Somatostatin-immunoreactive fiber projections into the brain stem and the spinal cord of the rat

Summary By use of the PAP-immunohistochemical staining technique with serial sections, somatostatin-immunoreactive fiber projections into the brain stem and the spinal cord are described. These projections originate in the periventricular somatostatin-immunoreactive perikarya of the hypothalamus and form three main pathways: (1) along the stria medullaris thalami and the fasciculus retroflexus into the interpeduncular nucleus; (2) along the medial forebrain bundle into the mammillary body; and (3) via the periventricular gray and the bundle of Schütz into the midbrain tegmentum. Densely arranged immunoreactive fibers and/or basket-like fiber terminals are observed within the following afferent systems: somatic afferent systems (nucleus spinalis nervi trigemini, substantia gelatinosa dorsalis of the entire spinal cord), and visceral afferent systems (nucleus solitarius, regio intermediolateralis and substantia gelatinosa of the sacral spinal cord). These projections form terminals around the perikarya of the second afferent neuron. Perikarya of the third afferent neuron are influenced by somatostatin-immunoreactive projections into the auditory system (nucleus dorsalis lemnisci lateralis, nucleus corporis trapezoidei). Furthermore, a somatostatin-immunoreactive fiber projection is found in the ventral part of the medial accessory olivary nucleus, in nuclei of the limbic system (nucleus habenularis medialis, nuclei supramamillaris and mamillaris lateralis) and in the formatio reticularis (nucleus Darkschewitsch, nuclei tegmenti lateralis and centralis, nucleus parabrachialis lateralis, as well as individual perikarya of the reticular formation). Targets of these projections are interneurons within interlocking neuronal chains.Supported by the Deutsche Forschungsgemeinschaft (Grant Nr. Kr 569/3) and Stiftung Volkswagenwerk     

Distribution of NT-IR perikarya in the brain of the guinea pig with special reference to cardiovascular centers in the medulla oblongata

Summary The occurrence and distribution of neurotensin-immunoreactive (NT-IR) perikarya was studied in the central nervous system of the guinea pig using a newly raised antibody (KN 1). Numerous NT-IR perikarya were found in the nuclei amygdaloidei, nuclei septi interventriculare, hypothalamus, nucleus parafascicularis thalami, substantia grisea centralis mesencephali, ventral medulla oblongata, nucleus solitarius and spinal cord. The distribution of NT-IR perikarya was similar to that previously described in the rat and monkey. In the gyrus cinguli, hippocampus and nucleus olfactorius, though, no NT-IR neurons were detected in this investigation. Additional immunoreactive perikarya, however, were observed in areas of the ventral medulla oblongata, namely in the nucleus paragigantocellularis, nucleus retrofacialis and nucleus raphe obscurus.The relevance of the NT-IR perikarya within the ventral medulla oblongata is discussed with respect to other neuropeptides, which are found in this area, and to cardiovascular regulation.Abbreviations abl nucleus amygdaloideus basalis lateralis - abm nucleus amygdaloideus basalis medialis - acc nucleus amygdaloideus centralis - aco nucleus amygdaloideus corticalis - ahp area posterior hypothalami - ala nucleus amygdaloideus lateralis anterior - alp nucleus amygdaloideus lateralis posterior - ame nucleus amygdaloideus medialis - atv area tegmentalis ventralis - bst nucleus proprius striae terminalis - CA commissura anterior - CC corpus callosum - cgld corpus geniculatum laterale dorsale - cglv corpus geniculatum laterale ventrale - cgm corpus geniculatum mediale - CHO chiasma opticum - CI capsula interna - co nucleus commissuralis - cod nucleus cochlearis dorsalis - cp nucleus caudatus/Putamen - cs colliculus superior - cu nucleus cuneatus - dmh nucleus dorsomedialis hypothalami - DP decussatio pyramidum - em eminentia mediana - ent cortex entorhinalis - epi epiphysis - FLM fasciculus longitudinalis medialis - fm nucleus paraventricularis hypothalami pars filiformis - FX fornix - gd gyrus dentatus - gp globus pallidus - gr nucleus gracilis - hl nucleus habenulae lateralis - hm nucleus habenulae medialis - hpe hippocampus - ift nucleus infratrigeminalis - io oliva inferior - ip nucleus interpeduncularis - LM lemniscus medialis - MT tractus mamillo-thalamicus - na nucleus arcuatus - nls nucleus lateralis septi - nms nucleus medialis septi - npca nucleus proprius commissurae anterioris - ns nucleus solitarius - n III nucleus nervi oculomotorii - nt V nucleus tractus spinalis nervi trigemini - ntm nucleus mesencephalicus nervi trigemini - osc organum subcommissurale - P tractus cortico-spinalis - PC pedunculus cerebri - PCI pedunculus cerebellaris inferior - pir cortex piriformis - pol area praeoptica lateralis - pom area praeoptica medialis - prt area praetectalis - pt nucleus parataenialis - pvh nucleus paraventricularis hypothalami - pvt nucleus paraventricularis thalami - r nucleus ruber - re nucleus reuniens - rgi nucleus reticularis gigantocellularis - rl nucleus reticularis lateralis - rm nucleus raphe magnus - ro nucleus raphe obscurus - rp nucleus raphe pallidus - rpc nucleus reticularis parvocellularis - rpgc nucleus reticularis paragigantocellularis - sch nucleus suprachiasmaticus - SM stria medullaris thalami - snc substantia nigra compacta - snl substantia nigra lateralis - snr substantia nigra reticularis - ST stria terminalis - tad nucleus anterior dorsalis thalami - tam nucleus anterior medialis thalami - tav nucleus anterior ventralis thalami - tbl nucleus tuberolateralis - tc nucleus centralis thalami - tl nucleus lateralis thalami - tmd nucleus medialis dorsalis thalami - TO tractus opticus - TOL tractus olfactorium lateralis - tpo nucleus posterior thalami - tr nucleus reticularis thalami - trs nucleus triangularis septi - TS tractus solitarius - TS V tractus spinalis nervi trigemini - tvl nucleus ventrolateralis thalami - vmh nucleus ventromedialis hypothalami - vh ventral horn, Columna anterior - zi zona incerta Supported by the Deutsche Forschungsgesellschaft (DFG) SFB 90, Carvas     

The distribution of corticotropin releasing factor-like immunoreactive neurons in rat brain

Using the indirect immunofluorescent technique, corticotropin releasing factor (CRF)-like immunoreactive nerve fibers and cell bodies were observed to be widely distributed in rat brain. A detailed stereotaxic atlas of CRF-like immunoreactive neurons was prepared. Large numbers of CRF-containing perikarya were observed in the nucleus paraventricularis, with scattered cells in the following nuclei: accumbens, interstitialis stria terminalis, preopticus medialis, supraopticus, periventricularis hypothalami, amygdaloideus centralis, dorsomedialis, substantia grisea centralis, parabrachialis dorsalis and ventralis, tegmenti dorsalis lateralis, vestibularis medialis, tractus solitarius and reticularis lateralis. The most intense staining of CRF-containing fibers was observed in the external lamina of the median eminence. Moderate numbers of CRF-like fibers were observed in the following nuclei: lateralis and medialis septi, tractus diagonalis, interstitialis stria terminalis, preopticus medialis, supraopticus, periventricularis thalami and hypothalami, paraventricularis, anterior ventralis and medialis thalami, rhomboideus, amygdaloideus centralis, habenulae lateralis, dorsomedialis, ventromedialis, substantia grisea centralis, cuneiformis, parabrachialis dorsalis and ventralis, tegmenti dorsalis lateralis, cerebellum, vestibularis medialis, reticularis lateralis, substantia gelatinosa trigemini and lamina I and II of the dorsal horn of the spinal cord. The present findings suggest that a CRF-like peptide may be involved in a neurotransmitter or neuromodulator role, as well as a hypophysiotropic role.     

Mapping of neurons in the central nervous system of the guinea pig by use of antisera specific to the molluscan neuropeptide FMRFamide

Summary Immunoreactive neurons were mapped in the central nervous system of colchicine-treated and untreated guinea pigs with the use of two antisera to the molluscan neuropeptide FMRFamide ¹. These antisera were especially selected for their incapability to react with peptides of the pancreatic polypeptide family. Only one group of perikarya was stained by both antisera; this group was mainly located in the nucleus dorsomedialis hypothalami and extended to the nucleus paraventricularis and nucleus periventricularis hypothalami. The perikarya were found to project fibers to all regions of the hypothalamus, to the septum, nucleus proprius striae terminalis, nucleus paraventricularis thalami, nucleus centralis thalami, nucleus reuniens, medial, central and basal amygdala, area praetectalis, area tegmentalis ventralis of Tsai, substantia grisea centralis mesencephali, formatio reticularis mesencephali, nucleus centralis superior, locus coeruleus, nuclei parabrachiales, nucleus raphe magnus, A 5-region, vagus-solitarius complex, ventral medulla, nucleus spinalis nervi trigemini, and substantia gelatinosa of the spinal cord. In many brain regions FMRFamide-immunoreactive processes were found in close contact with blood vessels.Abbreviations of Amino Acids D aspartic acid - F phenylalanine - G glycine - H histidine - L leucine - M methionine - P proline - R arginine - V valine - W tryptophan - Y tyrosine     

Vasoactive intestinal polypeptide immunoreactivity in the spinal cord of the guinea pig

Summary The distribution of vasoactive intestinal polypeptide-immunoreactive (VIP-IR) neurons in the lower medulla oblongata and the spinal cord has been analyzed in guinea pigs. This study includes results obtained by colchicine treatment and transection experiments. In the spinal cord, numerous VIP-IR varicosities were observed in the substantia gelatinosa of the columna dorsalis; some were also found in the substantia intermedia and the columna anterior. The spinal VIP-IR nerve fibers were mainly of intraspinal origin and oriented segmentally. VIP-IR nuclei in the spinal cord extended dorsally into corresponding regions of the caudal medulla oblongata, namely from the substantia intermedia medialis and lateralis into the vagus-solitarius complex and from the nucleus spinalis lateralis into the area of the nucleus reticularis lateralis. Additional VIP-IR perikarya were observed in the pars caudalis of the nucleus spinalis nervi trigemini. The VIP-IR nuclei within the caudal medulla oblongata probably form a continuous system with those localized within the spinal cord. They may be involved functionally in the modulation of cardiovascular and respiratory regulation in the guinea pig.Supported by the DFG, Carvas SFB 90     

大白鼠脚内核的传入性联系

众所周知,肉食动物和大白鼠的脚内核,相当于灵长类的内侧苍白球(Nagy et al.1978;Fox and Schmitz 1944);它们的细胞形态、传入及传出均相同。早期以及近年来的一些研究工作者,虽然在研究其他核团的投射时,联系到一些本核团的传入,但是尚缺乏对本核团传人的系统研究。本实验即是应用辣根过氧化物酶的逆行传递法来研究大白鼠脚内核的传入性联系。     

Afferent projections from the brainstem to the area hypothalamica dorsalis: a horseradish peroxidase study in the cat

Experiments using the retrograde transport of horseradish peroxidase were performed in order to identify the cells of origin the ascending projections from different brainstem regions to the area hypothalamica dorsalis (aHd) in the cat. The afferent inputs to this area originate mainly from the midbrain and medulla oblongata regions. The main afferent source of the area hypothalamica dorsalis arises from the substantia grisea centralis, where a large number of labeled cells were observed bilaterally, although more abundant on the ipsilateral side. Substantial afferents reach the aHd from the nuclei vestibularis medialis and inferior and the formatio reticularis mesencephali. A modest number of peroxidase-labeled neurons were observed in the nuclei ruber, interpeduncularis, substantia nigra, reticularis gigantocellularis, vestibularis lateralis, cuneatus and gracilis. From the pons, the nucleus raphe magnus sends a weak projection to the aHd. These anatomical data suggest that such area could be involved in visceral, sexual, nociceptive somatosensorial, sleep-waking and motor mechanisms.     

Somatostatin-immunoreactive nerve cell bodies and fibers in the medulla oblongata et spinalis.

Complete serial sectioning of the medulla oblongata in monkey, cat, guinea pig, and japanese dancing mouse and incubation for somatostatin-immunoreaction was carried out. Numerous regions of the medulla oblongata such as the nucleus reticularis gigantocellularis, nucleus cuneatus et gracillis, nucleus raphe magnus, nucleus tractus solitarius, nucleus vestibularis, and parts of the oliva contain dense networks of somatostatin-immunoreactive nerve fibers. Cell bodies were seen in the nucleus reticularis medullae oblongatae. In the spinal cord the sections from each segment were analyzed, showing the highest concentrations of somatostatinergic fibers in the substantia gelantinosa of the columna dorsalis. Cell bodies were seen in the zona intermedia centralis, especially in the upper cervical segments. Many positive fibers were also seen in the entire zona intermedia and the columna ventralis. Especially prominent was the immunoreactivity in the zona intermediolateralis of the thoracic segments and the columna ventralis of the lower lumbar and sacral segments.     

Distribution of NT-IR perikarya in the brain of the guinea pig with special reference to cardiovascular centers in the medulla oblongata

The occurrence and distribution of neurotensin-immunoreactive (NT-IR) perikarya was studied in the central nervous system of the guinea pig using a newly raised antibody (KN 1). Numerous NT-IR perikarya were found in the nuclei amygdaloidei, nuclei septi interventriculare, hypothalamus, nucleus parafascicularis thalami, substantia grisea centralis mesencephali, ventral medulla oblongata, nucleus solitarius and spinal cord. The distribution of NT-IR perikarya was similar to that previously described in the rat and monkey. In the gyrus cinguli, hippocampus and nucleus olfactorius, though, no NT-IR neurons were detected in this investigation. Additional immunoreactive perikarya, however, were observed in areas of the ventral medulla oblongata, namely in the nucleus paragigantocellularis, nucleus retrofacialis and nucleus raphe obscurus. The relevance of the NT-IR perikarya within the ventral medulla oblongata is discussed with respect to other neuropeptides, which are found in this area, and to cardiovascular regulation.     

Afferent brainstem projections to the hypothalmic locomotor region of the cat brain

The location of sources of direct projections to the hypothalamic locomotor region, electrical stimulation of which in the lightly anesthetized animal induced stepping along a moving treadmill, was studied by the retrograde axonal transport of horseradish peroxidase method in the cat brain stem. Different formations in the brain stem were shown to have direct connections with hypothalamic locomotor regions on both sides. Most sources of these afferent projections were located at sites of catecholamine- (nucl. reticularis lateralis, locus coeruleus, nucl. tractus solitarii) and serotonin-containing (nucl. raphe and substantia grisea centralis) neurons, parabrachial nuclei, and various sensory nuclei. Hypothalamic locomotor regions of both sides form bilateral connections.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 16, No. 3, pp. 353–362, May–June, 1984.     

Opiocortin and catecholamine projections to raphe nuclei

Afferent projections to the nucleus raphe magnus (NRM) and dorsal raphe nucleus (DRN) were identified using retrograde transport of horseradish peroxidase conjugated wheat germ agglutinin (HRP-WGA). Neurons were labeled in important nociceptive regions including periaqueductal gray (PAG), arcuate nucleus, lateral hypothalamus and medial thalamic nuclei following both injections. We have immunocytochemically identified opiocortin/WGA neurons in the arcuate nucleus following NRM and DRN injections. Dual stained catecholamine/WGA perikarya were found in zona incerta, locus coeruleus, substantia nigra, nucleus tractus solitarius and adjacent A2, C2 and C3, lateral paragigantocellular reticular nucleus/C1 and lateral reticular nucleus/A1 following DRN injections and in zona incerta, substantia nigra, nucleus tractus solitarius/A2 and lateral reticular nucleus/A1 after NRM injections. These results provide further evidence for opiocortin and catecholamine modulation of analgesia.     

Efferent connections of the centrum medianum of the cat thalamus revealed by autoradiography

Efferent connections of the centrum medianum and parafascicular nucleus of the thalamus (CM-Pf complex) in cats were studied by the method of anterograde axonal transport of tritiated amino acids followed by autoradiography. Projections from CM-Pf ascend to nuclei of the ventral group and nonspecific nuclei of the thalamus, preoptic, dorsal, lateral, and posterior areas of the hypothalamus, and also into the subthalamic region. Descending pathways are formed only by neurons of the caudomedial part of CM-Pf. They project into the pretectal region, superior colliculus, reticular formation, locus coeruleus, region of the ramus communicans, and substantia grisea centralis of the mesencephalon and pons, and also into the nuclei raphe, magnocellular reticular area, and inferior olivary nucleus of the medulla. In agreement with previous observations it was found that the caudomedial part of CM-Pf does not send direct projections into the cortex and striatum.I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. Translated from Neirofiziologiya, Vol. 16, No. 2, pp. 224–230, March–April, 1984.     

Neuronal-vascular relationships in the raphe nuclei, locus coeruleus, and substantia nigra in primates.

A fluorescence histochemical and electron microscopic study of the monoaminergic cell groups in the squirrel monkey and Rhesus monkey brains has revealed the direct apposition of blood vessels to perikarya and dendrites of monoaminergic neurons. Capillaries and small arterioles or venules, ranging from 8-50 microns in diameter, showed perikarya and dendrites abutting the basement membrane without evidence of glial interposition. This neuronal-vascular relationship was present in 20% to 30% of the small vessels in the serotonergic nuclei raphe dorsalis and centralis superior and in the noradrenergic locus coeruleus. Such contacts were clearly present but observed less frequently in the dopaminergic substantia nigra pars compacta and in the serotonergic nuclei raphe obscurus, pallidus, magnus, and pontis. We postulate that monoamine-containing neurons apposed to blood vessels in certain regions of the brain may be influenced directly by hormones or other substances in blood.     

Immunohistochemical mapping of galanin-like neurons in the rat central nervous system

Using an antiserum generated in rabbits against synthetic galanin (GA) and the indirect immunofluorescence method, the distribution of GA-like immunoreactive cell bodies and nerve fibers was studied in the rat central nervous system (CNS) and a detailed stereotaxic atlas of GA-like neurons was prepared. GA-like immunoreactivity was widely distributed in the rat CNS. Appreciable numbers of GA-positive cell bodies were observed in the rostral cingulate and medial prefrontal cortex, the nucleus interstitialis striae terminalis, the caudate, medial preoptic, preoptic periventricular, and preoptic suprachiasmatic nuclei, the medial forebrain bundle, the supraoptic, the hypothalamic periventricular, the paraventricular, the arcuate, dorsomedial, perifornical, thalamic periventricular, anterior dorsal and lateral thalamic nuclei, medial and central amygdaloid nuclei, dorsal and ventral premamillary nuclei, at the base of the hypothalamus, in the central gray matter, the hippocampus, the dorsal and caudoventral raphe nuclei, the interpeduncular nucleus, the locus coeruleus, ventral parabrachial, solitarii and commissuralis nuclei, in the A1, C1 and A4 catechaolamine areas, the posterior area postrema and the trigeminal and dorsal root ganglia. Fibers were generally seen where cell bodies were observed. Very dense fiber bundles were noted in the septohypothalamic tract, the preoptic area, in the hypothalamus, the habenula and the thalamic periventricular nucleus, in the ventral hippocampus, parts of the reticular formation, in the locus coeruleus, the dorsal parabrachial area, the nucleus and tract of the spinal trigeminal area and the substantia gelatinosa, the superficial layers of the spinal cord and the posterior lobe of the pituitary. The localization of the GA-like immunoreactivity in the locus coeruleus suggests a partial coexistence with catecholaminergic neurons as well as a possible involvement of the GA-like peptide in a neuroregulatory role.     

Immunofluorescence localization of corticoliberin neurons in the brain of pigeons

With immunofluorescence techniques using one anti-rat or two different anti-ovine CRF, the localization of corticotropin-releasing factor (CRF) producing neurons was characterized in frozen sections of pigeon brain. Colchicine was administered intraventricularly at various day hours. The CRF neurons were localized in the telencephalon: lobus parolfactorius, nucleus (n.) accumbens, anterior commissure; in the diencephalon: n. dorso-medialis and lateralis thalami and in different structures of the hypothalamus: n. praeopticus periventricularis and medialis, paraventricularis, supraopticus medialis, lateralis, ectomamillaris and in the stratum cellulare externum. Concerning the hypothalamic localizations, results are discussed in the light of physiological studies on corticotropic regulations in pigeons. Additional populations of CRF neurons were also located in various brainstem areas substantia grisea centralis, locus caeruleus, n. tegmenti dorsalis, sensorius principalis nervi trigemini, vestibularis latetalis, solitarius, nervi hypoglossi, in the dorsal area of the n. pontis lateralis and in the n. paramedianus paragiganto--cellularis, raphes, nervi facialis, subcaeruleus and the area ventralis. These particular localizations may lead to the assumption that CRF might be involved in nervous regulations other than those related to the corticotropic function.     

An HRP study in the cat of brainstem projections to the spinal cord, with particular reference to sacral afferents

Cells of origin of the spinal projections from the brainstem of the cat have been studied by means of retrograde axonal transport of horseradish peroxidase (HRP). Following injections of HRP into various levels of the spinal cord, many labeled cells were found in several structures in the brainstem. The labeled cells occurred in the raphe nuclei, reticular formation, vestibular complex, and nuclei of the dorsolateral pontine tegmentum. In the dorsolateral pontine tegmentum, many labeled cells were found in the nuclei of locus coeruleus, subcoeruleus and K?lliker-Fuse. In the coeruleus and subcoeruleus, the greatest number of labeled cells were found, when HRP was injected into the sacral cord. No difference emerged, however, in the number of labeled cells appearing in the K?lliker-Fuse nucleus after injection of the enzyme into different levels of the spinal cord. It appears that neurons in the lateral vestibular nucleus which project to different levels of the spinal cord are located in different parts of this nucleus.     

Electrophysiological Study of Supraspinal Input and Spinal Output of Cat's Subnucleus Reticularis Dorsalis (SRD) Neurons

This work addressed the study of subnucleus reticularis dorsalis (SRD) neurons in relation to their supraspinal input and the spinal terminating sites of their descending axons. SRD extracellular unitary recordings from anesthetized cats aimed to specifically test, 1) the rostrocaudal segmental level reached by axons of spinally projecting (SPr) neurons collateralizing or not to or through the ipsilateral nucleus reticularis gigantocellularis (NRGc), 2) whether SPr fibers bifurcate to the thalamus, and 3) the effects exerted on SRD cells by electrically stimulating the locus coeruleus, the periaqueductal grey, the nucleus raphe magnus, and the mesencephalic locomotor region. From a total of 191 SPr fibers tested to cervical 2 (Ce2), thoracic 5 (Th5) and lumbar5 (Lu5) stimulation, 81 ended between Ce2 and Th5 with 39 of them branching to or through the NRGc; 21/49 terminating between Th5 and Lu5 collateralized to or through the same nucleus, as did 34/61 reaching Lu5. The mean antidromic conduction velocity of SPr fibers slowed in the more proximal segments and increased with terminating distance along the cord. None of the 110 axons tested sent collaterals to the thalamus; instead thalamic stimulation induced long-latency polysynaptic responses in most cells but also short-latency, presumed monosynaptic, in 7.9% of the tested neurons (18/227). Antidromic and orthodromic spikes were elicited from the locus coeruleus and nucleus raphe magnus, but exclusively orthodromic responses were observed following stimulation of the periaqueductal gray or mesencephalic locomotor region. The results suggest that information from pain-and-motor-related supraspinal structures converge on SRD cells that through SPr axons having conduction velocities tuned to their length may affect rostral and caudal spinal cord neurons at fixed delays, both directly and in parallel through different descending systems. The SRD will thus play a dual functional role by simultaneously regulating dorsal horn ascending noxious information and pain-related motor responses.     

Medullary reticular neurons in the Japanese toad: morphologies and excitatory inputs from the optic tectum

1. To elucidate the neural mechanisms that mediate visual responses of optic tectum (OT) to medullary and spinal motor systems, we analyzed medullary reticular neurons in paralyzed Japanese toads (Bufo japonicus). We examined their responses to electrical stimulation of OT, and stained some neurons intracellularly. Responses to stimulation of the glossopharyngeal nerve (IX) were also analyzed. 2. Extracellular single unit recording revealed excitatory responses of medullary neurons to OT and IX stimulation. Among 92 units encountered, 79 responded to OT stimuli, 10 to IX stimuli, and 3 to both. Some units responded to successive stimuli of short intervals with relatively stable lags. 3. Intracellular recording and staining experiments revealed morphologies of reticular neurons that received excitatory inputs from OT. Thirteen units were identified after complete reconstruction of somata and dendrites. Neurons in the nucleus reticularis medius received excitatory inputs from bilateral OT. They had wide dendrites in ventral, ventrolateral and lateral funiculi, and single axons descending in the ipsilateral ventral funiculus as far caudally as the cervical spinal cord. Some collaterals of these axons projected directly to the hypoglossal and spinal motor nuclei. Some neurons in other medullary nuclei (nuc. reticularis superior, pretrigeminal nucleus, nuc. reticularis inferior, and nuc. tractus spinalis nervi trigemini) also responded to the OT stimulation. 4. Activities in bilateral OT converge onto medullary reticular neurons, which may directly control medullary and spinal motor systems.     

A critical examination of the occurrence of FMRFamide immunoreactivity in the brain of guinea pig and rat

Summary Several reports (cf. Weber et al. (1981) Science 214: 1248–1251) have described the extensive occurrence, in rat brain, of material immunologically related to the molluscan neuropeptide FMRFamide. We have reexamined these data in guinea pig and rat, using six different antisera to FMRFamide. Immunoreactive perikarya and fibres were found to be distributed throughout the rodent brain (Table 1). This distribution was roughly similar to that found by Weber and coworkers. However, solid-phase absorption of the antisera with bovine pancreatic polypeptide, which shares an arginine and an amidated aromatic amino acid (RYamide) with FMRFamide, showed that staining in most regions could be due to crossreactivity with bovine pancreatic polypeptide-like (or neuropeptide Y-like) material. Double-labelling experiments with antisera to FMRFamide and bovine pancreatic polypeptide led to the same conclusion. The only structures where no apparent crossreactivity occurred were perikarya and fibres in the nucleus dorsomedialis, ventromedialis, periventricularis and paraventricularis hypothalami and fibres in the area lateralis hypothalami, nucleus parabrachialis, substantia grisea centralis mesencephali, various parts of the formatio reticularis, and spinal cord. Hence only these structures might contain material which is more related to the molluscan retrapeptide.Used one-letter abbreviations of amino acids D aspartic acid - F phenylalanine - G glycine - H histidine - L leucine - M methionine - P proline - R arginine - T threonine - V valine - W tryptophan - Y tyrosine     

Effect of glutaraldehyde fixation on the localization of various oxidative and hydrolytic enzymes in the brain of rhesus monkey, Macaca mulatta

Synopsis Histochemical investigations have been made on the localization of certain oxidative and hydrolytic enzymes in the different areas of rhesus monkey brain using unfixed, freshfrozen tissue and 3% glutaraldehyde-fixed material. After glutaraldehyde fixation, the oxidative enzymes lose most of their activity normally demonstrable in the fresh-frozen section. The hydrolytic enzymes are somewhat resistant to fixation but also lose about half of the enzyme activity observed after no fixing procedure. The glycogen is better preserved in the glutaraldehyde-fixed material compared to fresh-frozen or even formaldehyde-fixed tissue. The significance of these observations is discussed in relation to glutaraldehyde as a fixative of choice in electron histochemistry.List of abbreviations used in the Figures ALH area lateralis hypothalami - APH area posterior hypothalami - AS aquaeductus Sylvii - ATN anterior thalamic nuclei - BC brachium conjunctivum - CC corpus callosum - CD nucleus caudatus - CI capsula interna - CIS cortex insularis - CM centrum medianum thalami - COR corona radiata - CP commissura posterior - CSR colliculus superior - EM eminentia medialis - F fornix - GC substantia grisea centralis - GLM corpus geniculatum laterale, magnocellular part - GLP corpus geniculatum laterale, parvocellular part - GP globus pallidus - LD nucleus lateralis dorsalis thalami - LME lamina medullaris externa thalami - LMI lamina medullaris interna thalami - LP nucleus lateralis posterior thalami - MD nucleus medialis dorsalis thalami - ML nucleus lateralis corpus mammillaris - MM nucleus medialis corpus mammillaris - NC nucleus centralis thalami - NCI nucleus colliculi inferioris - NLL nucleus lemnisci lateralis - NR nucleus ruber - NSTH nucleus subthalamicus - N III nervus oculomotorius - PC nucleus paracentralis thalami - PCR pedunculus cerebri - PUT Putamen - PV nucleus paraventricularis hypothalami - R nucleus reticularis thalami - RU nucleus reuniens thalami - SM stria medullaris thalami - SMH nucleus supramammillaris hypothalami - SMT nucleus submedius thalami - SN substantia nigra - TO tractus opticus - VL nucleus ventralis lateralis thalami - VP nucleus ventralis posterior thalami - ZI zona incerta - II ventriculus lateralis - III ventriculus tertius