System-specific distribution of zinc in the chick brain

Summary The brain of young domestic chicks was investigated using a Timm sulfide silver method. Serial Vibratome sections were analyzed under the light microscope, and the localization of zinc-positive structures in selected areas was determined at the ultrastructural level. Both strong and differential staining was visible in the avian telencephalon whereas most subtelencephalic structures showed a pale reaction. The highest staining intensity was found in the nonprimary sensory regions of the telencephalon such as the hyperstriatum dorsale, hyperstriatum ventrale, hippocampus, palaeostriatum augmentatum, lobus parolfactorius and caudal parts of neostriatum. There was an overall gradient of staining intensity in neostriatal areas from rostral to caudal with the heaviest zinc deposits in the caudal neostriatum. Primary sensory projection areas, such as the ectostriatum (visual), hyperstriatum intercalatum superius (visual), nucleus basalis (beak representation), the input layer L₂ of the auditory field L and the somatosensory area rostral to field L were selectively left unstained. Fiber tracts throughout the brain were free of zinc deposits except for glial cells. In electron micrographs of stained regions, silver grains were localized in some presynaptic boutons of asymmetric synapses (Gray type I), within the cytoplasm of neuronal somata and sporadically in the nucleus. The possible involvement of zinc in synaptic transmission and other processes is discussed.Abbreviations for Anatomical Structures used in the Text and Figures Ac Nucleus accumbens - Ad Archistriatum dorsale - Ai Archistriatum intermedium - Am Archistriatum mediale - Ap Archistriatum posterior - APH Area parahippocampalis - BAS Nucleus basalis - BO Bulbus olfactorius - Cb Cerebellum; - CbI Nucleus cerebellaris internus - CbM Nucleus cerebellaris intermedius - CDL Area corticoidea dorsolateralis - CPi Cortex piriformis - CT Commissura tectalis - DMP Nucleus dorsomedialis posterior thalami - E Ectostriatum - H Hyperstriatum - HA Hyperstriatum accessorium - HD Hyperstriatum dorsale - HIS Hyperstriatum intercalatum superius - Hp Hippocampus - HV Hyperstriatum ventrale - ICo Nucleus intercollicularis - Ipc Nucleus isthmi, pars parvocellularis - L Lingula - L _{1, 2, 3} Field L - La Nucleus laminaris - LFM Lamina frontalis suprema - LFS Lamina frontalis superior - LH Lamina hyperstriatica - LMD Lamina medullaris dorsalis - LNH Rostrolateral neostriatum/Hyperstriatum ventrale - LPO Lobus parolfactorius - M Medulla - MLd Nucleus mesencephalicus lateralis, pars dorsalis - MNH Rostromedial neostriatum/Hyperstriatum ventrale - N Neostriatum - NC Neostriatum caudale - NEB Nucleus of ectostriatal belt - NHA Nucleus of HA - PA Palaeostriatum augmentatum - Pap Nucleus papillioformis - PL Nucleus pontis lateralis - PP Palaeostriatum primitivum - RP Nucleus reticularis pontis caudalis - Rt Nucleus rotundus - S Nucleus septalis - SS Somatosensory area - TeO Tectum opticum - Tn Nucleus taeniae - TPO Area temporoparieto-occipitalis - V Ventricle - Va Vallecula     

The distribution of gonadotropin-releasing hormone (GnRH) neurons and fibers throughout the chick brain (Gallus domesticus)

Summary Nerve fibers and perikarya containing gonadotropin-releasing hormone (GnRH-like) immunoreactivity were investigated in the brain of the three-week-old chick, Gallus domesticus using the technique of immunocytochemistry. Six major groups of perikarya were found to include the olfactory bulb, olfactory tubercle/lobus parolfactorius, nucleus accumbens, septal preoptic hypothalamic region (three sub-nuclei), lateral anterior thalamic nucleus and in and about the oculomotor complex. The immunostaining was unusual in the latter group, suggesting that the neurons may contain a GnRH-II like material. Immunoreactive fibers for GnRH were found throughout the entire brain extending from the olfactory bulbs to the caudal brainstem. Two anatomical areas, not emphasized in the past literature, which had distinct GnRH-like immunoreactivity, included the lateral anterior thalamic nucleus and the preoptic recess. The former included a group of GnRH perikarya that is also known to be a retino-recipient area while the latter contained neuronal terminals some of which appeared to be contacting the cerebrospinal fluid of the preoptic recess. An attempt was made to list all anatomical structures that contained or were juxta-positioned to sites that displayed immunoreactive perikarya and fibers including circumventricular organs.Abbreviations used in figure legends Ac Nucleus accumbens - Ap Archistriatum posterior - APH Area parahippocampalis - AVT Area ventralis (Tsai) - BO Bulbus olfactorius - CA Commissura anterior (rostralis) - CDL Area corticoidea dorsolateralis - CO Chiasma opticum - CP Commissura posterior - CPi Cortex piriformis - CPP Cortex praepiriformis - CT Commissura tectalis - CTz Corpus trapezoideum - EW Nucleus of Edinger-Westphal - FV Funiculus ventralis - GCt Substantia grisea centralis - GLv Nucleus geniculatus lateralis, pars ventralis - HD Hyperstriatum dorsale - HM Nucleus habenularis medialis - Hp Hippocampus - ICo Nucleus intercollicularis - IH Nucleus inferior hypothalami - IN Nucleus infundibuli hypothalami - IP Nucleus interpeduncularis - LA Nucleus lateralis anterior (rostralis) thalami - LHy Regio lateralis hypothalami - LPO Lobus parolfactorius - LSO Organum septi lateralis (lateral septal organ) - LT Lamina terminalis - ME Eminentia mediana - INT. Z Internal zone - EXT. Z External zone - ML Nucleus mamillaris lateralis - MM Nucleus mamillaris medialis - nBOR Nucleus opticus basalis (n. of basal optic root) - nCPa Nucleus commissurae pallii - N III Nervus oculomotorius - N V Nervus trigeminus - n V M Nucleus mesencephalicus nervi trigemini - OA Nucleus olfactorius anterior (rostralis) - OMdl Nucleus nervi oculomotorii, pars dorsomedialis - OMv Nucleus nervi oculomotorii, pars ventralis - OVLT Organum vasculosum laminae terminalis - P Glandula pinealis - PA Palaeostriatum augmentatum (caudate putamen) - PHN Nucleus periventricularis hypothalami - POM Nucleus praeopticus medialis - POMn Nucleus praeopticus medianus - POP Nucleus praeopticus periventricularis - PP Palaeostriatum primitivum - PT Nucleus praetectalis - PVN Nucleus paraventricularis magnocellularis - RPaM Nucleus reticularis paramedianus - RPR Recessus praeopticus - b, RPR Basal region, RPR - F, RPR Floor, RPR - R, RPR Roof, RPR - S Nucleus tractus solitarii - SCO Organum subcommissurale - SGP Stratum griseum periventriculare - SHL Nucleus subhabenularis lateralis - SL Nucleus septalis lateralis - SM Nucleus septalis medialis - SO Stratum opticum - SSO Organum subseptale - TO Tuberculum olfactorium - TIO Tractus isthmo-opticus - TPc Nucleus tegmenti pedunculopontinus, pars compacta (substantia nigra) - TrO Tractus opticus - TSM Tractus septomesencephalicus - VeD Nucleus vestibularis descendens - VeM Nucleus vestibularis medialis - VL Ventriculus lateralis - VLT Nucleus ventrolateralis thalami - VO Ventriculus olfactorius - V III Ventriculus tertius (third ventricle)     

Biogene Amine im Gehirn vom Frosch (Rana esculenta)

Zusammenfassung Mit Hilfe der Methode zur fluoreszenzmikroskopischen Lokalisation von Catechol- und Tryptaminen wurde die Verteilung dieser Stoffe im ZNS von Rana esculenta untersucht. Catecholamin- und serotoninhaltige Neurone liegen im Nucleus reticularis mesencephali. Außerdem finden sich catecholaminhaltige Nervenzellen im Organon vasculosum hypothalami und in der Area praeoptica. Diese aminproduzierenden Zellen entsenden Zellfortsätze durch die Ependymschicht in den Ventrikel. Über diese Ausläufer erfolgt möglicherweise eine Sekretion biogener Amine in den Liquor cerebrospinalis. Catecholamin- und serotoninhaltige Axone erreichen voneinander verschiedene Kerngebiete und Areale. Neben dem periventrikulären Zellager im Tuber cinereum und in der Area praeoptica werden vor allem der ventrolaterale Teil des lateralen Septumkerns, Striatum ventrale und Epistriatum von Endstrecken catecholaminhaltiger Axone durchdrungen. Serotoninhaltige Varicositäten finden sich dagegen vor allem in Kerngebieten, die in sensorische Bahnen eingeschaltet sind (Nucleus isthmi, corpus geniculatum laterale, Area praetectalis, Tectum opticum, Thalamus dorsalis, Neostriatum). Weitere Ausbreitungsgebiete 5-Hydroxytryptamin-haltiger Fasern sind die Habenula und der Nucleus interpeduncularis, Kerngebiete, über die Erregungen aus dem limbischen System auf vegetative Zentren der Medulla oblongata geleitet werden.

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Biogenic amines in the brain of the frog (Rana esculenta)

Summary The distribution of biogenic amines in the central nervous system of Rana esculenta was investigated by means of the fluorescence-microscopical detection of catecholand tryptamines. The nucleus reticularis mesencephali was found to contain numerous neurones rich in catechol- and tryptamines. Apart from this nucleus nerve cells in the organon vasculosum hypothalami and in the area praeoptica were found to contain catecholamines. The clublike processes of these neurones penetrate the ependymal layer and extend into the ventricle. These structures are presumably responsible for a secretion of biogenic amines into the cerebrospinal fluid. Catecholamine- and serotonin-containing axons terminate on different nuclei and areas. Besides the periventricular cellular layer of the tuber cinereum and the area praeoptica, the pars ventrolateralis of the nucleus septalis lateralis, striatum ventrale and epistriatum are pervaded by terminals of catecholamine-containing neurons. Serotonincontaining varicosities are mainly to be found in nuclei, which are intercalated in sensory pathways (nucleus isthmi, corpus geniculatum laterale, area praetectalis, tectum opticum, thalamus dorsalis, neostriatum). Further areas of distribution of 5-hydroxytryptamine-fibers are the habenula and the nucleus interpeduncularis, nuclei which coordinate impulses from the limbic system projecting them on visceral centers of the medulla oblongata.

Mit dankenswerter Unterstützung durch die Deutsche Forschungsgemeinschaft.     

Sensory inputs to the nucleus basalis prosencephali,a feeding-pecking centre in the pigeon

Summary Evoked potentials were recorded from the nucleus basalis prosencephali (Bas) of the pigeon through chronically implanted electrodes. The auditory sensitivity of the Bas was assessed by the amplitude of the potentials. Audiograms thus obtained were comparable to those similarly measured from stations of the orthodox auditory pathway and resembled those obtained by others with behavioural techniques from the same species. The sensitivity to vibration applied to the beak was also measured. The vibrogram revealed two separate optima, one located in the lower frequency and another in the higher frequency region. These were shown to be due to trigeminal mechanoreceptive sensitivity and to bone/cochlea mediated sound sensitivity, respectively. Evoked potentials of the Bas in response to vestibular stimulation are described for the first time. The possibility that they were artefacts was excluded with several control procedures. These findings confirm recent anatomical evidence of a direct pathway from the vestibular nucleus to the nucleus basalis prosencephali. All afferents to the Bas are discussed in conjunction with the probable function of the nucleus as a sensorimotor coordinator of the pigeon's pecking/feeding behaviour.Abbreviations A archistriatum - aL area L of the medial neostriatum caudale - Bas nucleus basalis prosencephali - Cb cerebellum - FA tractus fronto-archistriatalis - HA hyperstriatum accessorium - Hp hippocampus - HRP horseradish peroxidase - HV hyperstriatum ventrale - LLv nucleus lemnisci lateralis, pars ventralis - LPO lobus parolfactorius - MV nucleus motorius nervi trigemini - MLd nucleus mesencephalicus lateralis, pars dorsalis - nVI nucleus nervi facialis - nVIII nervus vestibulocochlearis - N neostriatum - NFL neostriatum frontolaterale - OM tractus occipitomesencephalicus - Ov nucleus ovoidalis - PrV nucleus sensorius principalis nervi trigemini - QF tractus quintofrontalis - Rpv nucleus reticularis parvocellularis, pars lateralis - TrO tractus opticus - VS nucleus vestibularis superior     

Localization of neuropeptide Y-immunoreactive cells and fibres in the brain of the Japanese quail

Summary In the present study, we have demonstrated, by means of the biotin-avidin method, the widespread distribution of neuropeptide Y (NPY)-immunoreactive structures throughout the whole brain of the Japanese quail (Coturnix coturnix japonica). The prosencephalic region contained the highest concentration of both NPY-containing fibres and perikarya. Immunoreactive fibres were observed throughout, particularly within the paraolfactory lobe, the lateral septum, the nucleus taeniae, the preoptic area, the periventricular hypothalamic regions, the tuberal complex, and the ventrolateral thalamus. NPY-immunoreactive cells were represented by: a) small scattered perikarya in the telencephalic portion (i.e. archistriatal, neostriatal and hyperstriatal regions, hippocampus, piriform cortex); b) medium-sized cell bodies located around the nucleus rotundus, ventrolateral, and lateral anterior thalamic nuclei; c) small clustered cells within the periventricular and medial preoptic nuclei. The brainstem showed a less diffuse innervation, although a dense network of immunopositive fibres was observed within the optic tectum, the periaqueductal region, and the Edinger-Westphal, linearis caudalis and raphes nuclei. Two populations of large NPY-containing perikarya were detected: one located in the isthmic region, the other at the boundaries of the pons with the medulla. The wide distribution of NPY-immunoreactive structures within regions that have been demonstrated to play a role in the control of vegetative, endocrine and sensory activities suggests that, in birds, this neuropeptide is involved in the regulation of several aspects of cerebral functions.Abbreviations AA archistriatum anterius - AC nucleus accumbens - AM nucleus anterior medialis - APP avian pancreatic polypeptide - CNS centrai nervous system - CO chiasma opticum - CP commissura posterior - CPi cortex piriformis - DIC differential interferential contrast - DLAl nucleus dorsolateralis anterior thalami, pars lateralis - DLAm nucleus dorsolateralis anterior thalami, pars medialis - E ectostriatum - EW nucleus of Edinger-Westphal - FLM fasciculus longitudinalis medialis - GCt substantia grisea centralis - GLv nucleus geniculatus lateralis, pars ventralis - HA hyperstriatum accessorium - Hp hippocampus - HPLC high performance liquid chromatography - HV hyperstriatum ventrale - IF nucleus infundibularis - IO nucleus isthmo-opticus - IP nucleus interpeduncularis - IR immunoreactive - LA nucleus lateralis anterior thalami - LC nucleus linearis caudalis - LFS lamina frontalis superior - LH lamina hyperstriatica - LHRH luteinizing hormone-releasing hormone - LoC locus coeruleus - LPO lobus paraolfactorius - ME eminentia mediana - N neostriatum - NC neostriatum caudale - NPY neuropeptide Y - NIII nervus oculomotorius - NV nervus trigeminus - NVI nervus facialis - NVIIIc nervus octavus, pars cochlearis - nIV nucleus nervi oculomotorii - nIX nucleus nervi glossopharyngei - nBOR nucleus opticus basalis (ectomamilaris) - nCPa nucleus commissurae pallii - nST nucleus striae terminalis - OM tractus occipitomesencephalicus - OS nucleus olivaris superior - PA palaeostriatum augmentatum - PBS phosphate-buffered saline - POA nucleus praeopticus anterior - POM nucleus praeopticus medialis - POP nucleus praeopticus periventricularis - PP pancreatic polypeptide - PYY polypeptide YY - PVN nucleus paraventricularis magnocellularis - PVO organum paraventriculare - R nucleus raphes - ROT nucleus rotundus - RP nucleus reticularis pontis caudalis - Rpc nucleus reticularis parvocellularis - RPgc nucleus reticularis pontis caudalis, pars gigantocellularis - RPO nucleus reticularis pontis oralis - SCd nucleus subcoeruleus dorsalis - SCv nucleus subcoeruleus ventralis - SCNm nucleus suprachiasmaticus, pars medialis - SCNl nucleus suprachiasmaticus, pars lateralis - SL nucleus septalis lateralis - SM nucleus septalis medialis - Ta nucleus tangentialis - TeO tectum opticum - Tn nucleus taeniae - TPc nucleus tegmenti pedunculo-pontinus, pars compacta - TSM tractus septo-mesencephalicus - TV nueleus tegmenti ventralis - VeL nucleus vestibularis lateralis - VLT nucleus ventrolateralis thalami - VMN nucleus ventromedialis hypothalami A preliminary report of this study was presented at the 15th Conference of European Comparative Endocrinologists, Leuven, Belgium, September 1990     

Comparative immunocytochemical localization of putative opioid ligands in the central nervous system

Summary We report a detailed comparative immunocytochemical mapping of enkephalin, CCK and ACTH/gb-endorphin immunoreactive nerves in the central nervous system of rat and guinea pig. Enkephalin immunoreactivity was detected in many groups of nerve cell bodies, fibers and terminals in the limbic system, basal ganglia, hypothalamus, thalamus, brain stem and spinal cord. -endorphin and ACTH immunoreactivity was limited to a single group of nerve cell bodies in and around the arcuate nucleus and in fibers and terminals in the midline areas of the hypothalamus, thalamus and mesencephalic periaqueductal gray with lateral extensions to the amygdaloid area. Cholecystokinin immunoreactive nerve fibers and terminals displayed a distribution similar to that of enkephalin in many regions; but striking differences were also found. An immunocytochemical doublestaining technique, which allowed simultaneous detection of two different peptides in the same tissue section, showed that enkephalin-, CCK- and ACTH/-endorphin-immunoreactive nerves although closely intermingled in many brain areas, occurred separately. The distributions of nerve terminals containing these neuropeptides showed striking overlaps and also paralleled the distribution of opiate receptors. This may suggest that enkephalin, CCK, ACTH and -endorphin may interact with each other and with opiate receptors.Index of Abbreviations CA Commissura anterior - CAI Capsula interna - CO Chiasma opticum - CPF Cortex piriformis - CSDD Commissura supraoptica dorsalis, pars dorsalis (Ganser) - CSDV Commissura supraoptica dorsalis, pars ventralis (Meynert) - FMP Fasciculus medialis prosencephali - FOR Formatio reticularis - GD Gyrus dentatus - GP Glubus pallidus - H Habenula - HI Hippocampus - S Subiculum - SGCD Substantia grisea centralis, pars dorsalis - SGCL Substantia grisea centralis, pars lateralis - SGPV Substantia grisea periventricularis - SNC Substantia nigra, zona compacta - SNL Substantia nigra, pars lateralis - ST Stria terminalis - STP Stria terminalis, pars precommissuralis - TD Tractus diagonalis (Broca) - TO Tractus opticus - TSHT Tractus septohypothalamicus - TUOP Tuberculum olfactorium, pars corticalis - SUM Decussatio supramamillaris - a Nucleus accumbens - ac Nucleus amygdaloideus centralis - aco Nucleus amygdaloideus corticalis - am Nucleus amygdaloideus medialis - ar Nucleus arcuatus - cp Nucleus caudatus putamen - dcgl Nucleus dorsalis corporis geniculati lateralis - em Eminentia mediana - fm Nucleus paraventricularis, pars magnocellularis - fp Nucleus paraventricularis, pars parvocellularis - ha Nucleus anterior (hypothalami) - hd Nucleus dorsomedialis (hypothalami) - hl Nucleus lateralis (hypothalami) - hp Nucleus posterior (hypothalami) - hpv Nucleus periventricularis (hypothalami) - hv Nucleus ventromedialis (hypothalami) - ip Nucleus interpeduncularis - mcgm Nucleus marginalis corporis geniculatic medialis - mm Nucleus mammillaris medialis - ml Nucleus mammillaris lateralis - mh Nucleus medialis habenulae - p Nucleus pretectalis - pf Nucleus parafascicularis - pom Nucleus preopticus medialis - pop Nucleus preopticus periventricularis - posc Nucleus preopticus, pars suprachiasmatica - pt Nucleus paratenialis - pvs Nucleus periventricularis stellatocellularis - re Nucleus reuniens - sc Nucleus suprachiasmaticus - sl Nucleus septi lateralis - so Nucleus supraopticus - st Nucleus interstitialis striae terminalis - tad Nucleus anterior dorsalis thalami - tam Nucleus anterior medialis thalami - tav Nucleus anterior ventralis thalami - td Nucleus tractus diagonalis (Broca) - th Nuclei thalami - tl Nucleus lateralis thalami - tlp Nucleus lateralis thalami, pars posterior - tm Nucleus medialis thalami - tml Nucleus medialis thalami, pars lateralis - tmm Nucleus medialis thalami, pars medialis - tpo Nucleus posterior thalami - tr Nucleus reticularis thalami - tv Nucleus ventralis thalami - tvd Nucleus ventralis thalami, pars dorsomedialis - tvm Nucleus ventralis medialis thalami, pars magnocellularis     

黄雀发声核团与部分听觉中枢内P物质的分布和性双态比较

用免疫组织化学方法研究P物质在雌雄黄雀发声控制核团和听觉中枢内的分布,结合计算机图像分析仪检测SP免疫阳性细胞和末梢的灰度值,并作雌雄比较。结果如下：1．在发声学习中枢嗅叶X区有大量的SP阳性神经末梢和一些神经细胞。2．在发声控制核团前脑高级发声中枢(HVc)、古纹状体栎核、发声学习中枢新纹状体巨细胞核和丘脑背内侧核外侧部内有许多的SP免疫阳性细胞。3．在发声控制中枢中脑背内侧核和延髓舌下神经核气管鸣管部、听觉中枢丘脑卵圆核的壳区、中脑背外侧核壳区及中脑丘间核等有密集的SP免疫阳性神经末梢和纤维分布;雄性发声中枢内SP的分布比雌性丰富,两者有显著的差异。结果表明：SP的分布在雌雄发声中枢之间存在显著的性双态;SP广泛分布于黄雀发声控制核团和部分听觉中枢内,提示SP可能在发声控制及听觉中枢内具有重要的生理功能。     

Afferent connections of the optic tectum in channel catfish Ictalurus punctatus

Summary Horseradish peroxidase was injected unilaterally into the optic tectum of the channel catfish, Ictalurus punctatus. The sources of tectal afferents were thereby revealed by retrogradely labeled neurons in various brain centers. Retrogradely labeled cells were seen in both the ipsilateral and contralateral telencephalon. The superficial pretectal area was labeled on both sides of the brain. Ipsilateral projections were also observed coming from the entopeduncular nucleus. Both the anterior thalamic nucleus and the ventro-medial thalamic nucleus projected to the ipsilateral optic tectum. Cells in the ipsilateral nucleus of the posterior commissure were seen to project to the tectum. Labeled fibers were visualized in the lateral geniculate nucleus ipsilateral to the injected tectum, however, no labeled cell bodies were observed. Therefore, tectal cells project to the lateral geniculate nucleus, but this projection is not reciprocal. No labeled cells were found in the cerebellum. Labeled cells occurred in both the ipsilateral and contralateral medial reticular formation; they were also observed in the ipsilateral nucleus isthmi. A projection was seen coming from the dorsal funicular nucleus. Furthermore, labeled cells were shown in the inferior raphe nucleus.Abbreviations AP Area pretectalis - C Cerebellum - DPTN Dorsal posterior tegmental nucleus - H Habenula - IRF Inferior reticular formation - LI Inferior lobe - LGN Lateral geniculate nucleus - LR Lateral recess - MB Mammillary body - MRF Medial reticular formation - MZ Medial zone of the telencephalon - NC Nucleus corticalis - NDL-M Nucleus opticus dorsolateralis/pars medialis - NI Nucleus isthmi - NPC Nucleus of the posterior commissure - OPT Optic tectum - OT Optic tract - PC Posterior commissure - PN Pineal organ - PrOP Preoptic nucleus - PT Pretectum - TBt Tectobulbar tract - TEL Telencephalon - TL Torus longitudinalis - TS Torus semicircularis - VC Valvula cerebelli - VLTN Ventrolateral thalamic nucleus - VMTN Ventromedial thalamic nucleus     

Functional organization of some auditory nuclei in the Guinea Fowl demonstrated by the 2-Deoxyglucose technique

Summary The auditory pathway of the Guinea Fowl was labeled with [C¹⁴]2-deoxy-D-glucose after stimulation with pure tones, harmonic tones and species-specific calls. In addition to other auditory nuclei, which showed more or less uniform labeling with the present technique, the n. mesencephalicus lateralis dorsalis (MLD) of the midbrain, as well as field L and parts of the hyperstriatum ventrale in the telencephalon, showed a stripe-pattern of labeling after stimulation with a pure tone. The position and orientation of the tone-activated striped areas in field L, observed after stimulation with different tones, correspond to isofrequency contours obtained with microelectrode recordings. The labeling of the three congruent tonotopically organized layers of field L (L₁, L₂, and L₃) was not uniform along the anterior-posterior axis of the field.Harmonic tones produced multiple reactive stripes each of which corresponded to the stripe characteristic of a particular harmonic presented as a pure tone. The species-specific Iambus-call labeled the tonotopic area of field L that corresponds to the frequency band with the highest energy of the call. The hyperstriatum ventrale generally showed a weaker pattern of labeling that, however, resembled the labeling in field L.     

In situ demonstration of changes in the preoptico-neurohypophysical complex after electrical stimulation of the olfactory tract in the catfish Clarias batrachus (Linn.)

Summary Electrical stimulation (five minutes) of the olfactory tract in Clarias batrachus results in total degranulation of the neurons of the pars magnocellularis (PMC), while a ten-minute treatment is required for degranulation of the entire nucleus preopticus (NPO). The preoptico-neurohypophysial tract (PNT) and neurohypophysis (NH) of these animals are feebly stained. By 15 minutes of stimulation the neurosecretory material (NSM) is depleted from the entire system; only a few granules may be present in the PNT and NH. A delay for 30 minutes after a 15-minute stimulation causes restoration of NSM in the NH and PNT, while a 60-minute delay results in a higher degree of accumulation of NSM.

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Zusammenfassung Eine 5 min dauernde elektrische Stimulierung des Tractus olfactorius von Clarias batrachus bewirkt eine vollständige Entgranulierung der sekretorischen Neurone der Pars magnocellularis nuclei praeoptici (PMC), während für die Entgranulierung des ganzen Nucleus praeopticus (NPO) eine Stimulierungsdauer von 10 min erforderlich ist. Die Neurosekretfärbung des Tractus praeoptico-neurohypophyseus (PNT) und der Neurohypophyse (NH) fällt bei diesen Versuchstieren mäßig aus. Nach 15 minütiger Stimulierung ist das färbbare Material (NSM) im ganzen neurosekretorischen System weitgehend abgebaut; nur noch wenige Granula finden sich im PNT und in der NH. Eine Ruhephase von 30 min, die auf eine 15 minütige Stimulierung folgt, führt zum Wiederauftreten des NSM in der NH und im PNT, während nach einer 60 minütigen Pause die Menge des NSM weiter zunimmt.

     

Functional organization of the avian auditory field L

Summary The 2-deoxyglucose (2DG) autoradiographic method is used to analyse the functional organization of the auditory forebrain nucleus, field L, in parrots, ducks, pigeons, gulls and passerine birds. The data are compared to earlier studies in domestic and Guinea fowls. In all birds field L is a trilaminar structure, placed at the border between neostriatum mediale and caudale. The orientation and spatial extent within the forebrain, however, shows considerable variability. There is a close spatial relationship between field L and the overlying hyperstriatum ventrale, which is a secondary auditory center receiving input from field L. Stimulation with tones produces stripe like patterns of metabolic activity which are continuous across the layers of field L and the hyperstriatum ventrale. In all birds the position of the stripes in both areas shift in medio-lateral direction with decreasing tone frequency. In none of the birds the representation of frequencies above 3 kHz cover more than 20% of the neuronal space. Thus, high frequency hearing is underrepresented. Frequencies between 500 Hz and 3 kHz with somewhat variable representation, cover most of the neuronal space. Fowls and pigeons appear to have a low frequency specialization in field L.Abbreviations 2DG 2-deoxyglucose - FM frequency modulated     

A thalamo-cerebral connection in vocal center of canary

Canary song is controlled by two groups of thalamo-cerebral nuclei. One, the hyperstriatum ventrale pars caudale (HVc) and the robust nucleus of the archistriatum (RA), is a motor driving system for vocalization. The other group, which includes the HVc, the nucleus magnocellularis of neostriatum (MAN), Area X and the nucleus dorsointermedius posterior thalami (DIP), modulates the driving system. The HVc receives synaptic projections from the MAN and sends fibers to Area X. Axons of Area X monosynaptically innervate the thalamic nucleus, the DIP, from which neurons extend axons back to the cerebral nucleus, the MAN. DIP neurons relay incoming impulses by way of Area X to the MAN. Double labeling of DIP neurons with HRP and Fast Blue shows that axonal terminals from Area X connect directly with DIP neurons which send fibers to the MAN. The axon formed a bulge from which multiple branches extended to the postsynaptic cell bodies covering most of the surface. The structure of the DIP synapse may be related to a characteristic pattern of discharge of the DIP neuron, which is transmitted over thalamic projection to cerebral vocal nuclei.     

Gap detection in the starling (Sturnus vulgaris)

Summary Gap-detection thresholds of single units were determined from auditory forebrain neurons of the awake starling. Nine different response types were statistically defined from the discharge pattern to a 400 ms broadband noise stimulus. The gap stimuli consisted of two broadband noise bursts which were separated by a gap ranging from 0.4 to 204.8 ms duration. The median minimumdetectable gap for 121 out of 145 units that had a significant threshold 204.8ms was 12.8 ms; 20% of the neurons showed thresholds between 0.4 and 3.2 ms. The neurons of the nine response types differed significantly in their minimum-detectable gaps; neurons with phasic-tonic and phasic excitation exhibited the best (i.e. shortest) minimum-detectable gaps. The neurons of the three different recording areas (field L, NCM and HV) were significantly different in their minimumdetectable gaps; field L neurons showed the best temporal resolution for gaps in broadband noise. Gap-detection thresholds are compared with psychophysical thresholds determined with the same stimuli and the relevance of forebrain units for temporal resolution is discussed.Abbreviations CS control stimulus - HV hyperstriatum ventrale - HVc hyperstriatum ventrale pars caudalis - NB noise burst - NCM neostriatum caudale pars medialis - NS noise stimulus - SGS standard gap series - TW time window     

Sensory projections to the nucleus basalis prosencephali of the pigeon

Summary The afferent pathways to the nucleus basalis prosencephali of the pigeon were studied by use of the horseradish peroxidase (HRP) technique. It was confirmed that this nucleus receives a direct pathway from the nucleus sensorius principalis nervi trigemini and that, as in the starling, it receives a direct input from the nucleus lemnisci lateralis, pars ventralis, an auditory relay. Totally novel is the finding that the nucleus basalis prosencephali is the target of a direct pathway originating in the medullary nucleus vestibularis superior. All three pathways bypass the thalamus. From within the telencephalon the nucleus basalis prosencephali also receives fibres from the tuberculum olfactorium and the peri-ectostriatal belt, suggestive of olfactory and visual input. Marked cell bodies were also found in the neostriatum frontolaterale. It is assumed that these arose from HRP uptake by axons of the tractus fronto-archistriatalis that course through the nucleus basalis prosencephali to the anterodorsal archistriatum. Marked fibres and bouton-like formations were observed in the latter structure. The afferents to the nucleus basalis prosencephali are discussed in conjunction with the probable role of the nucleus as a sensorimotor coordinator of the pecking/feeding behaviour of the pigeon.     

Das visuelle System von Zonotrichia leucophrys gambelii

Zusammenfassung Der Verlauf der Sehbahn und die Lokalisation der optischen Zentren wurden bei Zonotrichia leucophrys gambelii (nordamerikanischer Ammernfink) nach einseitiger Augenexstirpation mit den Techniken von Nauta-Fink-Heimer, Bodian und Bielschowsky erforscht. Die Untersuchungen erstreckten sich über einen Zeitraum von 3 bis zu 120 Tagen nach der Operation. Zonotrichia leucophrys gambelii besitzt ein für Vögel typisches visuelles System. Die Hauptmasse der Optikusfasern endet im Stratum griseum et fibrosum superficiale des Tectum opticum. Weitere zentrale Endgebiete sind: Nucleus geniculatus lateralis, Nucleus lateralis anterior, Nucleus superficialis synencephali, Nucleus externus, tectales Grau und Nucleus ectomamillaris als Kern der basalen optischen Wurzel. Alle Fasern werden im Chiasma opticum total gekreuzt, auch der Tractus isthmo-opticus, ein efferentes Bündel, dessen Ursprung im Nucleus isthmo-opticus zu finden ist. Dieses efferente Fasersystem läßt sich im Stumpf des durchtrennten N. opticus noch 120 Tage nach der Operation gut versilbern. Eine direkte Verbindung von Retina und Hypothalamus war lichtmikroskopisch nicht nachweisbar. Neurosekretorisch aktive Zellen des Hypothalamus können zwar einen engen räumlichen Kontakt mit den optischen Fasern haben, Synapsen sind aber an diesen Stellen nicht zu erkennen. Es werden passagere Opticusfasern beschrieben, die auf dem Weg zum Nucleus lateralis anterior und Nucleus superficialis synencephali den Hypothalamus durchsetzen.

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Neurohistological and experimental studies of the visual system in Zonotrichia leucophrys gambelii

Summary The course of the optic pathways and the positions of the optic centers have been investigated with unilaterally enucleated white-crowned sparrows, Zonotrichia leucophrys gambelii, using the techniques of Nauta-Fink-Heimer, Bodian, and Bielachowsky. The investigation involved birds examined 3–120 days after enucleation. The white-crowned sparrow has a typically avian visual system. The major bundles of optic fibers terminate in the stratum griseum et fibrosum superficiale of the tectum opticum. Further terminal areas are the nucleus geniculatus lateralis, nucleus lateralis anterior, nucleus superficialis synencephali, nucleus externus, the tectal gray, and the nucleus ectomamillaris of the basal optic root. There is a complete crossing of all fibers in the chiasma, including those of the tractus isthmo-opticus, an efferent bundle with its origin in the nucleus isthmo-opticus. This efferent fiber system can be well impregnated in the stump of the sectioned optic nerve up to 120 days after the operation. No direct connection between the retina and hypothalamus could be demonstrated by light microscopy. Hypothalamic neurosecretory cells can occur in close contact with optic fibers but no synapses have been recognized. Some optic fibers pass through the hypothalamus enroute to the nucleus lateralis anterior and the nucleus superficialis synencephali.

Mit Unterstützung durch die Deutsche Forschungsgemeinschaft. Herrn Prof. Dr. D.S. Farner, Department of Zoology, University of Washington, Seattle, Wash., danke ich für die Förderung dieser Studien (National Institutes of Health Research Grant No. 5 ROI NB 06187 to Professor D. S. Farner).     

Catecholamine im Gehirn der Eidechse (Lacerta viridis und Lacerta muralis)

Zusammenfassung Mit Hilfe der Methode zur fluoreszenzmikroskopischen Lokalisation von Catechol- und Tryptaminen wurde die Verteilung von Catecholaminen im Zentralnervensystem von Lacerta viridis und muralis untersucht. Die meisten Kerngebiete des Mittel-, Zwischen- und Vorderhirns werden von Endaufsplitterungen catecholaminhaltiger Neurone erreicht, deren Verteilungsmuster für jedes Kerngebiet charakteristisch ist; die Ursprungsgebiete dieser Fasersysteme liegen im Tegmentum (Nucleus reticularis mesencephali) und im Hypothalamus (Nucleus diffusus tuberis). Außer diesen Ursprungskernen findet sich im Hypothalamus ein paraventrikulär gelegenes, catecholaminhaltiges Kerngebiet (Nucleus ependymalis hypothalami), dessen kurze, transmitterreiche Neurone die Hauptkerngebiete des Hypothalamus (Nucleus ventromedialis tuberis; Area praeoptica) und wahrscheinlich auch die Commissurenkerne innervieren.Spektrographische und histochemische Befunde legen die Vermutung nahe, daß die fluoreszierende Substanz im Palaeostriatum von Lacerta hauptsächlich Noradrenalin ist und daß die Neurone des Nucleus ependymalis hypothalami neben Adrenalin primäre Catecholamine enthalten. Es wird die Möglichkeit diskutiert, daß die im ZNS von Lacerta nachgewiesenen Catecholamine als Transmitterstoffe wirken.

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Summary The distribution of catecholamines in the central nervous system of Lacerta viridis and muralis was investigated by means of the method for fluorescence-microscopical detection of catechol- and tryptamines. Most nuclear areas of the mes-, di- and telencephalon receive terminal ramifications of catecholamine-containing neurones, the distribution pattern of which is typical for each nucleus; these neurones originate in the tegmentum (nucleus reticularis mesencephali) and in the hypothalamus (nucleus diffusus tuberis). Apart from these nuclei another paraventricular nucleus (nucleus ependymalis hypothalami) was found to contain catecholamines. The short neurones of this nucleus mainly innervate the nucleus ventromedialis tuberis and the area praeoptica. It is assumed that these neurones also supply the nuclei commissurales of the telencephalon.According to the results of spectrographical and histochemical tests it is assumed that the fluorescent substance in the palaeostriatum of Lacerta is mainly noradrenaline and that the neurones of the nucleus ependymalis hypothalami besides little adrenaline contain huge amounts of primary catecholamines. The possibility of the fluorescent substances acting as transmitters is discussed.

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Mit dankenswerter Unterstützung durch die Deutsche Forschungsgemeinschaft und die Joachim Jungius-Gesellschaft zur Förderung der Wissenschaften, Hamburg.     

Retinohypothalamic projections and immunocytochemical analysis of the suprachiasmatic region of the desert iguana Dipsosaurus dorsalis

Two separate and distinct retinal projections to the hypothalamus in the iguanid lizard Dipsosaurus dorsalis were described using horseradish peroxidase and cobalt-filling techniques. Both of the projections were unilateral and completely crossed; one terminated in the supraoptic nucleus and the other in the suprachiasmatic nucleus. Immunocytochemical analysis showed that the supraoptic nucleus contained cell bodies and fibers that cross-react with antibodies raised against arginine vasopressin, while the suprachiasmatic nucleus contained arginine vasopressin-like immunoreactive fibers emanating from cells in the nearby paraventricular nucleus. The suprachasmatic nucleus contained a dense plexus of fibers that cross-reacted with neuropeptide-Y antibody. Antiserum against vasoactive intestinal polypeptide showed no reactivity in any part of the forebrain, while antiserum against serotonin showed sparse and uniform reactivity throughout the forebrain, including the suprachiasmatic nucleus. These results, together with other data, indicate that the suprachiasmatic nucleus of D. dorsalis is homologous to the suprachiasmatic nuclei of rodents, structures known to contain circadian pacemakers. We suggest that the suprachiasmatic nucleus may play a similar role in the circadian system of D. dorsalis.     

Postnatal development of central auditory frequency maps

Summary In the early postnatal period of many mammals and in the perihatching period of chicks the auditory ranges are restricted to the species-specific low- and mid-frequency ranges. During subsequent development, the high frequency hearing expands (depending on the species) by 1–4 octaves. Adult-like audition is established between the 4th and the 7th week. It is still discussed controversially, how the extension of the auditory ranges relates to the maturation of orderly frequency representation in the cochleae of the respective species. The present review summarizes investigations of the development of tonotopy in nuclei of the central auditory system, and discusses how the centrally acquired data might contribute to the understanding of the maturation of cochlear stimulus transduction and to the development of frequency maps.Abbreviations ANF auditory nerve fibers - BF best frequency - CN cochlear nucleus - DAB days after birth - DCN dorsal cochlear nucleus - IC inferior colliculus - IHC inner hair cells - HS Hipposideros speoris - LSO lateral superior olive - MGB medial geniculate body (auditory thalamus) - NL Nucleus laminaris - NM Nucleus magnocellularis - OHC outer hair cells - RR Rhinolophus rouxi - SOC superior olivary complex - 2-DG 2-deoxyglucose     

Distribution of gastrin-releasing peptide immunoreactivity in the brain of the collared dove (Streptopelia decaocto)

The distribution of immunoreactivity after applying an antibody against gastrin-releasing peptide (GRP) was studied in the brain of the collared dove (Streptopelia decaocto). In the forebrain GRP-immunoreactive (GRP-ir) cells were found in the hyperstriatum accessorium, medial and lateral parts of the neostriatum, corticoidea dorsolateralis and temporoparieto-occipitalis areas, hippocampus, pre- and parahippocampal areas and prepiriform cortex. In the brainstem, GRP-ir cells were restricted mainly to the substantia nigra and ventral tegmental nucleus. Areas with densely packed GRP-ir clusters of varicosities were the medial intermediate hyperstriatum ventrale and lateral septal nucleus; dense GRP-ir neuropil was found in the parolfactory lobe, and in the dorsal half of the intermediate and caudal archistriatum. The ventral lamina medullaris contained many GRP-ir fibers. Forebrain areas devoid of immunoreactivity were the basal nucleus, ectostriatum, rostral archistriatum, most of the paleostriatum augmentatum and the lateral bed nucleus of the stria terminalis. Moderate densities of GRP-ir elements were found in the other telencephalic areas and further in, among others, the preoptic and hypothalamic region, ventral area of Tsai, cerulean nuclei, parabrachial complex, dorsal glossopharyngeal and vagus motor nuclei and medial nuclei of the solitary complex. The observations are compared with data from the literature and the implications for the definition of specific centers within the avian brain are discussed, with emphasis on systems with a role in visceral and motivational functions and in learning.     

Distribution of the nuclear receptor for vitamin D in female and male zebra finches,Taeniopygia guttata

In this study, we describe the distribution of high affinity binding sites for 1,25(OH)₂-vitamin D₃ (1,25-D₃) in the zebra finch (Taeniopygia guttata). Four hours following the injection of tritiated 1,25-D₃, binding of the steroid hormone was found primarily in the cell nuclei of a variety of differnt organs. Neurons in numerous discrete regions of the forebrain were labeled. These forebrain regions included the nucleus accumbens, nucleus dorsomedialis posterior thalami, lobus parolfactorius, nucleus septalis lateralis and medialis, nucleus septalis, lamina medullaris dorsalis, nucleus striae terminalis, palaeostriatum augmentatum, and stratum griseum. The choroid plexuses, however, remained clear. Labeled cells were seen in several organs of the alimentary canal, in both the exocrine and the endocrine pancreas, in the proximal tubules of the kidney, in the spleen, in the bursa of Fabricius, and in the heart. The basal cells of the uropygial gland were also labeled. No specific retention was evident in the gonads of either sex. Vitamin D is thus bound by cells in systems with widely different functions. Since several of the labeled tissues are not primarily involved in calcium homeostasis, the data support the concept that vitamin D-soltriol is a steroid hormone that acts as a seasonal neuroendocrine-endocrine regulator and somatotrophic modulator.