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.     

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     

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     

Afferent and efferent connections of the sexually dimorphic medial preoptic nucleus of the male quail revealed by in vitro transport of DiI

The medial preoptic nucleus of the Japanese quail is a testosterone-sensitive structure that is involved in the control of male copulatory behavior. The full understanding of the role played by this nucleus in the control of reproduction requires the identification of its afferent and efferent connections. In order to identify neural circuits involved in the control of the medial preoptic nucleus, we used the lipophilic fluorescent tracer DiI implanted in aldheyde-fixed tissue. Different strategies of brain dissection and different implantation sites were used to establish and confirm afferent and efferent connections of the nucleus. Anterograde projections reached the tuberal hypothalamus, the area ventralis of Tsai, and the substantia grisea centralis. Dense networks of fluorescent fibers were also seen in several hypothalamic nuclei, such as the anterior medialis hypothalami, the paraventricularis magnocellularis, and the ventromedialis hypothalami. A major projection in the dorsal direction was also observed from the medial preoptic nucleus toward the nucleus septalis lateralis and medialis. Afferents to the nucleus were seen from all these regions. Implantation of DiI into the substantia grisea centralis also revealed massive bidirectional connections with a large number of more caudal mesencephalic and pontine structures. The substantia grisea centralis therefore appears to be an important center connecting anterior levels of the brain to brain-stem nuclei that may be involved in the control of male copulatory behavior.     

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)     

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     

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.     

The rat submaxillary gland contains predominantly P-type tachykinin binding sites

The specific binding of the ¹²⁵I-Bolton-Hunter labeled tachykinins substance K (BHSK), eledoisin (BHE), and substance P (BHSP) was examined in crude membrane suspensions and by autoradiography in rat submaxillary gland. All three ligands at 0.1 nM concentrations exhibited binding that was inhibited by tachykinins in a potency rank order of substance P > physalaemin > substance K > eledoisin > kassinin > neuromedin K with slope factors essentially equal to unity. All tachykinins were 5 to 10 times more potent in inhibiting BHSK and BHE binding compared to BHSP binding. Autoradiographic visualization of BHSK and BHSP binding sites in the gland revealed extensive labeling of mucous and serous acini. The intensity of labeling was much less for BHSK than for BHSP. The results indicate that the rat submaxillary gland contains predominantly P-type tachykinin binding sites.     

Molecular evolution of prepro-thyrotropin-releasing hormone in the chicken (Gallus gallus) and its expression in the brain

A cDNA encoding prepro-thyrotropin-relaesing hormone (ppTRH) in chicken (Gallus gallus) was isolated and the sites of expression in the brain were determined. The chicken ppTRH cDNA encodes 260 amino acids, including four TRH progenitor sequences (-Lys/Arg-Arg-Gln-His-Pro-Gly-Lys/Arg-Arg-). It is interesting to note that chicken ppTRH harbors four TRH progenitor-like sequences. According to the hydropathy profile of chicken ppTRH, not only the TRH progenitor sequences but also the TRH progenitor-like sequences are localized in hydrophilic regions. The TRH progenitor-like sequences might be related to structural conservation in the evolution of ppTRH, although they cannot be processed into TRH due to the mutation of several amino acids. According to the alignment of the deduced amino-acid sequences of known vertebrate ppTRHs and the molecular phylogenetic tree we constructed, we speculate on the molecular evolution of ppTRH in vertebrates. In situ hybridization demonstrated experession of the ppTRH gene in the nucleus preopticus periventricularis, nucleus preopticus medialis, regio lateralis hypothalami, paraventricular nucleus, nucleus periventricularis hypothalami, and nucleus ventromedialis hypothalami in the chicken brain.     

Action of the newly discovered mammalian tachykinins, substance K and neuromedin K, on gastroduodenal motility of anesthetized dogs

The present experiments examined the local effects of two new mammalian tachykinins isolated from porcine spinal cord, substance K and neuromedin K, on gastroduodenal motility of anesthetized dogs. Tachykinins were injected through the gastroepiploic and cranial pancreaticoduodenal arteries at concentrations ranging from 1 to 100 ng/ml. Substance K, neuromedin K and substance P increased gastroduodenal smooth muscle contractions in a dose-dependent manner. The contractile response of the gastric antrum to newly discovered tachykinins was not as long-lasting as that to substance P. The potencies of various tachykinins on contractile responses showed the following rank order of potencies: physalaemin = eledoisin = substance P greater than substance K = neuromedin K in gastric smooth muscle; physalaemin = substance P = eledoisin greater than substance K = neuromedin K in the duodenal smooth muscle. Administration of atropine (100-200 micrograms/kg) inhibited the effect of tachykinins both in the gastric antrum and in the proximal duodenum. These results indicate that substance K and neuromedin K could act as transmitters or as modulators of neuronal activity influencing gastroduodenal motility.     

Possible influence of tachykinins on body fluid homeostasis in the rat

The effect on water intake, urine flow and vasopressin release of intracranial injections of substance P, physalaemin and eledoisin was studied in Wistar and Brattleboro, homozygous and heterozygous, rats. The tachykinins strongly inhibited water intake both in Wistar and in Brattleboro, homozygous and heterozygous, rats. Physalaemin and eledoisin reduced urine flow in Wistar and heterozygous, but not in homozygous, Brattleboro rats. Substance P never affected urine elimination. Physalaemin and eledoisin produced a dose-dependent, long lasting release of vasopressin in Wistar rats. Substance P did not affect the release of vasopressin. The results suggest that both substance P and physalaemin could influence brain mechanisms which control water intake, acting as thirst inhibitors, and that physalaemin could also participate in body fluid control by conserving water through vasopressin release.     

Pharmacologic characterization and autoradiographic distribution of binding sites for iodinated tachykinins in the rat central nervous system

P-type, E-type, and K-type tachykinin binding sites have been identified in the mammalian CNS. These sites may be tachykinin receptors for which the mammalian neuropeptides substance P, neuromedin K, and substance K are the preferred natural agonists, respectively. In the present investigation, we have compared the pharmacology and the autoradiographic distribution of CNS binding sites for the iodinated (¹²⁵I-Bolton-Hunter reagent) tachykinins substance P, eledoisin, neuromedin K, and substance K. Iodinated eledoisin and neuromedin K exhibited an E-type binding pattern in cortical membranes. Iodinated eledoisin, neuromedin K, and substance K each labeled sites that had a similar distribution but one that was considerably different from that of sites labeled by iodinated substance P. CNS regions where there were detectable densities of binding sites for iodinated eledoisin, neuromedin K, and substance K and few or no sites for iodinated substance P included cortical layers IV–VI, mediolateral septum, supraoptic and paraventricular nuclei, interpeduncular nucleus, ventral tegmental area, and substantia nigra pars compacta. Binding sites for SP were generally more widespread in the CNS. CNS regions where there was a substantial density of binding sites for iodinated substance P and few or no sites for iodinated eledoisin, neuromedin K, and substance K included cortical layers I and II, olfactory tubercle, nucleus accumbens, caudate-putamen, globus pallidus, medial and lateral septum, endopiriform nucleus, rostral thalamus, medial and lateral preoptic nuclei, arcuate nucleus, dorsal raphe nucleus, dorsal parabrachial nucleus, parabigeminal nucleus, cerebellum, inferior olive, nucleus ambiguus, retrofacial and reticular nuclei, and spinal cord autonomic and somatic motor nuclei. In the brainstem, iodinated substance P labeled sites in both sensory and motor nuclei whereas iodinated eledoisin, neuromedin K, and substance K labeled primarily sensory nuclei. Our results are consistent with either of two alternatives: (1) that iodinated eledoisin, neuromedin K, and substance K bind to the same receptor site in the rat CNS, or (2) that they bind to multiple types of receptor sites with very similar distribution.     

Luminal tachykinin receptors on canine tracheal epithelium: functional subtyping

Luminal addition of tachykinins to the open-circuited canine tracheal epithelium produces a biphasic response in the transmucosal potential difference (PD). A rapid, transient decrease is followed by a subsequent rise, both phases being associated with changes in conductance. Concentration-response curves demonstrated the following orders of potency: substance P greater than physalaemin greater than eledoisin = kassinin for the tachykinins, and substance P greater than substance P-(4-11) greater than substance P-(6-11) using the C-terminal fragments. Both sequences are similar to those reported for the dog carotid artery. These observations were confirmed by cross-tachyphylaxis experiments. SP-O-methyl ester, a selective agonist for the SP-P (or NK-1) receptor, elicited identical responses, and exhibited cross-tachyphylaxis to substance P. Bradykinin produced similar luminal responses, though different receptors are involved, since no cross-tachyphylaxis was observed between bradykinin and the tachykinins.     

Distribution of FMRFamide-like immunoreactivity in the brain of the elasmobranch fish Scyliorhinus canicula.

The distribution of FMRFamide-like-immunoreactive peptides was investigated in the brain and pituitary of the elasmobranch fish Scyliorhinus canicula using the indirect immunofluorescence technique. FMRFamide-immunoreactive cells and fibers were mainly observed in the telencephalon and the diencephalon, while other brain structures were almost unstained. In the telencephalon, FMRFamide-like-containing neurons were seen in the caudal part of the area periventricularis pallialis, in the posterior area of the nucleus septi medialis and in the nucleus septi caudoventralis. In the diencephalon, numerous FMRFamide-positive cell bodies were observed in the hypothalamus, ventral thalamus and posterior tuberculum. The highest density of immunofluorescent perikarya was found in the nucleus lobi lateralis hypothalami and in the nucleus periventricularis hypothalami. More caudally, the mesencephalon and the caudal brainstem only contained scattered varicose FMRFamide-immunoreactive fibers. Stained fibers were also identified in the median eminence and several FMRFamide-like-positive cells were detected in the dorsal and rostral parts of the neurointermediate lobe of the pituitary. These data indicate that substances related to the molluscan cardioexcitatory peptide FMRFamide are widely distributed in the brain of S. canicula, suggesting their implication in neuroendocrine and/or neuromodulatory functions.     

Demonstration and Distribution of Kassinin-Like Material (Substance K) in the Rat Central Nervous System

Antiserum was raised against kassinin in rabbits. Cross-reactivity with other tachykinins was determined; these included substance K (100%) and substance P (0.1%). Peptides extracted from rat brain and synthetic tachykinins were chromatographed by reverse-phase HPLC. The major peak of kassinin-like material eluted at a time different from that of synthetic kassinin, eledoisin, physalaemin, neurokinin beta, and substance P but coeluted with substance K. Measurement of kassinin-like material in macrodissected and microdissected brain regions indicated that the distribution of kassinin-like material was similar to that of substance P.     

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     

Demonstration of two distinct tachykinin receptors in rat brain cortex

Eledoisin and substance P are members of a class of peptides termed tachykinins. They share a similar spectrum of biological activities but their relative potencies in various pharmacological assays differ. We have investigated whether there is more than one receptor for these tachykinins in rat brain cortex membranes. 125I-Bolton Hunter-conjugated eledoisin specifically binds to rat brain cortex membranes with high affinity. The binding is inhibited over 95% by unlabeled eledoisin (6.6 microM). Scatchard analysis of the binding of this ligand is curvilinear suggesting that there are two binding sites with KD values of 0.9 +/- 0.7 nM and 20 +/- 10 nM. We tested various analogs and fragments of substance P and eledoisin for their ability to inhibit the binding of 125I-Bolton Hunter-conjugated eledoisin and 125I-Bolton Hunter-conjugated substance P to these membranes. The following peptides are more potent as inhibitors of the 125I-Bolton Hunter-conjugated eledoisin binding site than of the 125I-Bolton Hunter-conjugated substance P binding site: nonradioactive Bolton Hunter-conjugated eledoisin (greater than 100-fold), eledoisin (12-fold), kassinin (22-fold), neuromedin K (greater than 58-fold), and pyroglutamyl substance P(6-11)hexapeptide (4-fold). In contrast, substance P (21-fold), physalaemin (8-fold), and substance P methyl ester (1200-fold) were more potent as inhibitors of 125I-Bolton Hunter-conjugated substance P binding. These results suggest that these two ligands may bind to distinct receptors. 125I-Bolton Hunter-conjugated substance P binds specifically to rat parotid cell receptors, but 125I-Bolton Hunter-conjugated eledoisin does not, indicating that parotid cells contain only one of the receptor subtypes. The cortex membrane binding of both ligands is stimulated by low concentrations of MnCl2 (ED50 = 0.05 mM) and is inhibited by guanylyl-5'-(beta, gamma-imido)diphosphate (IC50 = 0.5 microM).     

Autoradiographic studies with 3H dihydrotestosterone in the brain of sex reversed mice, heterozygous for androgen insensitive testicular feminization (Tfm). A comparison with normal female mice and sex reversed male mice

Specific binding sites for 3H dihydrotestosterone are demonstrated by autoradiography in brain nuclei of sex reversed mice heterozygous for testicular feminization (Tfm) which are phenotypically intersexes with testes and accessory sex glands that consist of a mosaic of androgen insensitive Tfm cells which lack specific dihydrotestosterone binding and androgen sensitive normal cells. The nuclear group evaluated include: nucleus (n.) septi lateralis, n. interstitialis striae terminalis, n. medialis amygdalae, the hypothalamic n. arcuatus, n. ventromedialis lateralis, n. pre-mammillaris ventralis, n. preopticus medialis, and nuclei of the cranial nerves VII, X, and XII. In the sex reversed males and the female, used as controls, the frequency of neurons with specific DHT binding show a distinct male-female difference in the caudal part of the arcuate nucleus. In the sex reversed Tfm heterozygotes, in all brain nuclei studied, the frequency of labeled neurons is reduced. The extent of reduction of androgen binding in the different brain nuclei varies among as well as within individual sex reversed Tfm heterozygotes, suggesting variations of the ratio of normal to Tfm neurons in sex reversed Tfm heterozygotes. The differentially reduced androgen binding of different brain systems corresponds to a differentially reduced androgen dependent behaviour reported in the literature.     

Immunohistochemical Localization of C-RFamide, a FMRF-related Peptide, in the Brain of the Goldfish, Carassius auratus

Carassius RFamide (C-RFa) is a novel peptide found in the brain of the Japanese crucian carp. It has been demonstrated that mRNA of C-RFa is present in the telencephalon, optic tectum, medulla oblongata, and proximal half of the eyeball in abundance. Immunohistochemical methods were employed to elucidate the distribution of the peptide in the brain of the goldfish (Carassius auratus) in detail. C-RFaimmunoreactive perikarya were observed in the olfactory bulb, the area ventralis telencephali pars dorsalis and lateralis, nucleus preopticus, nucleus preopticus periventricularis, nucleus lateralis tuberis pars posterioris, nucleus posterioris periventricularis, nucleus ventromedialis thalami, nucleus posterioris thalami, nucleus anterior tuberis, the oculomotor nucleus, nucleus reticularis superior and inferior, facial lobe, and vagal lobe. C-RFa immunoreactive fibers and nerve endings were present in the olfactory bulb, olfactory tract, area dorsalis telencephali pars centralis and medialis, area ventralis telencephali, midbrain tegmentum, diencephalon, medulla oblongata and pituitary. However, in the optic tectum the immunopositive perikarya and fibers were less abundant. Based on these results, some possible functions of C-RFa in the nervous system were discussed.     

Binding sites for tachykinin peptides in the brain and stomach of the dogfish, Scyliorhinus canicula.

In membranes of dogfish brain and stomach, two binding sites for tachykinins were identified. One site specifically bound [125I]-Bolton-Hunter substance P (BH-SP) and the rank potency of tachykinins to compete for BH-SP binding revealed similarities with the rank potency of an NK1 receptor. The pharmacology of the other site, which specifically bound [125I]-Bolton-Hunter scyliorhinin II (BH-Scy II), did not resemble any of the mammalian tachykinin receptors. The rank potency to inhibit BH-Scy II binding to this second site was: scyliorhinin II approximately scyliorhinin I greater than eledoisin approximately substance P approximately neurokinin A greater than phyllomedusin approximately physalaemin greater than [Sar9Met(O2)11]substance P. Neurokinin B and senktide did not displace BH-Scy II binding. In addition, nucleotide analogues inhibited BH-SP binding but not BH-Scy II binding. Our binding data suggest the existence of a mammalian-like NK1 receptor and of a nonmammalian tachykinin receptor in the dogfish.