Galanin-like immunoreactivity in the chicken brain

The anatomical distribution of neurons containing galanin has been studied in the central nervous system of the chicken by means of immunocytochemistry using antisera against rat galanin. Major populations of immunostained perikarya were detected in several brain areas. The majority of galanin-immunoreactive cell bodies was present in the hypothalamus and in the caudal brainstem. Extensive groups of labeled perikarya were found in the paraventricular, periventricular, dorsomedial and tuberal hypothalamic nuclei, and in the nucleus of the solitary tract in the medulla oblongata. In the telencephalon, immunoreactive perikarya were observed in the preoptic area, in the lateral septal nucleus and in the hippocampus. The mesencephalon contained only a few galanin-positive perikarya located in the interpeduncular nucleus. Immunoreactive nerve fibers of varying density were detected in all subdivisions of the brain. Dense accumulations of galanin-positive fibers were seen in the preoptic area, periventricular region of the diencephalon, the ventral hypothalamus, the median eminence, the central gray of the brainstem, and the dorsomedial caudal medulla. The distributional pattern of galanin-immunoreactive neurons suggests a possible involvement of a galanin-like peptide in several neuroregulatory mechanisms.     

Peptide YY-like immunoreactivity in the central nervous system of the rat

The concentration of peptide YY (PYY)-like immunoreactivity in rat brain and spinal cord was determined by radioimmunoassay. The highest concentrations were found in the cervical spinal cord (18.1 +/- 1.3 ng/g, mean +/- S.E.M.) and in the medulla oblongata (16.3 +/- 1.5 ng/g). Lower amounts were found in the pons and in the hypothalamus. Chromatographic analysis of the PYY-like immunoreactivity from various regions of the brain revealed 95% of the immunoreactive material to be indistinguishable from synthetic porcine PYY. PYY-immunoreactive nerve cell bodies could be demonstrated by immunocytochemistry in the medulla oblongata of colchicine-treated rats, the largest group of cells being found in the midline area between and partly in the raphe pontis and obscurus nuclei. Another large group of immunoreactive cells was detected more laterally in the medial parts of the gigantocellular reticular nucleus. A few cells, finally, were seen in the dorsal parts of the medulla, including the nucleus of the solitary tract. Varicose nerve fibers displaying PYY immunoreactivity were observed in many parts of the hypothalamus, pons, medulla and spinal cord.     

Distribution of immunoreactive thyrotropin-releasing hormone in the forebrain and hypophysis of the bullfrog,Rana catesbeiana

The distribution of immunoreactive thyrotropin-releasing hormone (TRH) in the forebrain and hypophysis of Rana catesbeiana was studied by means of specific radioimmunoassay and immunohistochemistry based on peroxidase-antiperoxidase (PAP) techniques. A relatively high concentration of immunoassayable TRH is present in the hypothalamus. Immunoreactive TRH cell bodies are found in the anterior part of the preoptic nucleus, the dorsal infundibular nucleus, the nucleus of diagonal band of Broca, and the medial part of the amygdala. Immunoreactive nerve terminals are observed in the neurohypophysis and the external layer of the median eminence, where the terminals are in close contact with the capillary loops of the hypophyseal portal vessels. The possible role of TRH in the frog brain is discussed.     

Topographical localisation of endothelin mRNA and peptide immunoreactivity in neurones of the human brain

The distribution of endothelin mRNA and immunoreactivity in the human brain was investigated using the technique of in situ hybridization and immunocytochemistry. Cryostat sections from 22 cases of neurologically normal adult human brain, collected 3-7 h post-mortem were hybridized with 35S-labelled complementary (c)RNA probes prepared from the 3' non-coding region of endothelin-1 cDNA, and the chromosomal genes encoding endothelin-2 and -3. In situ hybridization with all three cRNA probes revealed labelled neuronal cell bodies in laminae III-VI of the parietal, temporal and frontal cortices. Labelled cells were also seen, scattered throughout the para- and periventricular, supraoptic and lateral hypothalamic nuclei, the caudate nucleus, amygdala, hippocampus, basal nucleus of Meynert, substantia nigra, raphe nuclei, Purkinje cell layer of the cerebellum and in the dorsal motor nuclei of the vagus of the medulla oblongata. The distribution of neurones immunoreactive to endothelin was similar to that of endothelin mRNA, although fewer immunoreactive cells throughout the brain, were noted. Immunoreactive fibres were present mainly in the cortex and hypothalamus, and to a lesser extent in the brain stem. Combined in situ hybridization and immunocytochemistry on the same section revealed the presence of endothelin-1 mRNA and immunoreactivity in the same cortical neuronal cell. Colocalisation studies in the cortex revealed endothelin-1 mRNA and immunoreactivity in a number of cells which also expressed neuropeptide Y mRNA and immunoreactivity. In the hypothalamus and basal nucleus of Meynert endothelin immunoreactivity was colocalised to a subset of neurophysin- and galanin-immunoreactive cell bodies respectively. Endothelin mRNA and immunoreactivity was also seen in some blood vessel endothelial cells. The findings of endothelin mRNAs and immunoreactivity in heterogenous neuronal populations further emphasises the potential role of endothelin as a neuropeptide, probably having diverse actions in the nervous system of man.     

New data on the immunocytochemical localization of thyrotropin-releasing hormone in the rat central nervous system

An antiserum raised against the synthetic tripeptide pyroglutamyl-histidyl-proline (free acid) was used to localize thyrotropin-releasing hormone (TRH) in the rat central nervous system (CNS) by immunocytochemistry. The distribution of TRH-immunoreactive structures was similar to that reported earlier; i.e., most of the TRH-containing perikarya were located in the parvicellular part of the hypothalamic paraventricular nucleus, the suprachiasmatic portion of the preoptic nucleus, the dorsomedial nucleus, the lateral basal hypothalamus, and the raphe nuclei. Several new locations for TRH-immunoreactive neurons were also observed, including the glomerular layer of the olfactory bulb, the anterior olfactory nuclei, the diagonal band of Broca, the septal nuclei, the sexually dimorphic nucleus of the preoptic area, the reticular thalamic nucleus, the lateral reticular nucleus of the medulla oblongata, and the central gray matter of the mesencephalon. Immunoreactive fibers were seen in the median eminence, the organum vasculosum of the lamina terminalis, the lateral septal nucleus, the medial habenula, the dorsal and ventral parabrachial nuclei, the nucleus of the solitary tract, around the motor nuclei of the cranial nerves, the dorsal vagal complex, and in the reticular formation of the brainstem. In the spinal cord, no immunoreactive perikarya were observed. Immunoreactive processes were present in the lateral funiculus of the white matter and in laminae V-X in the gray matter. Dense terminal-like structures were seen around spinal motor neurons. The distribution of TRH-immunoreactive structures in the CNS suggests that TRH functions both as a neuroendocrine regulator in the hypothalamus and as a neurotransmitter or neuromodulator throughout the CNS.     

Glucagon-related peptides in the rat hypothalamus

Summary Immunohistochemically, nerve fibers and terminals reacting with anti-N-terminal-specific but not with anti-C-terminal-specific glucagon antiserum were observed in the following rat hypothalamic regions: paraventricular nucleus, supraoptic nucleus, anterior hypothalamus, arcuate nucleus, ventromedial hypothalamic nucleus and median eminence. Few fibers and terminals were demonstrated in the lateral hypothalamic area and dorsomedial hypothalamic nucleus. Radioimmunoassay data indicated that the concentration of gut glucagon-like immunoreactivity was higher in the ventromedial nucleus than in the lateral hypothalamic area. In food-deprived conditions, this concentration increased in both these parts. This was also verified in immunostained preparations in which a marked enhancement of gut glucagon-like immunoreactivity-containing fibers and terminals was observed in many hypothalamic regions. Several immunoreactive cell bodies were found in the ventromedial and arcuate nuclei of starved rats. Both biochemical and morphological data suggest that glucagon-related peptides may act as neurotransmitters or neuromodulators in the hypothalamus and may be involved in the central regulatory mechanism related to feeding behavior and energy metabolism.     

Immunocytochemical localization of growth hormone releasing factor (GHRF)-containing structures in the rat brain using anti-rat GHRF serum

The distribution of growth hormone releasing factor (GHRF) immunoreactive structures in the rat hypothalmus was studied after colchicine treatment with PAP immunocytochemistry in vibratome sections using an antiserum directed to rat hypothalamic GHRF. The majority of the GHRF-immunoreactive cell bodies were found in the arcuate nucleus, the medial perifornical region, and the ventral premammillary nuclei of the hypothalamus. Scattered cells were seen in the lateral basal hypothalamus, the medial and lateral portions of the ventromedial nucleus, and the dorsomedial and paraventricular nuclei. Immunoreactive fibers were observed in all the regions mentioned above. GHRF terminals were located in the central region of the median eminence. In addition, GHRF-immunoreactive neuronal processes were seen in the ventral region of the dorsomedial nucleus, the medial preoptic and suprachiasmatic regions, dorsal portion of the suprachiasmatic nucleus, bed nucleus of the stria terminals and the hypothalamic portion of the stria terminals. The localization of GHRF-immunoreactive terminals in the median eminence reinforces the view that GHRF plays a physiological role in the regulation of pituitary function. In addition, the localization of GHRF-immunoreactive structures in areas not usually considered to project to the median eminence suggest that GHRF may act as a neuromodulator or neurotransmitter.     

Calcitonin gene-related peptide: detailed immunohistochemical distribution in the central nervous system

With the use of an antiserum generated in rabbits against synthetic human calcitonin gene-related peptide (CGRP) the distribution of CGRP-like immunoreactive cell bodies and nerve fibers was studied in the rat central nervous system. A detailed stereotaxic atlas of CGRP-like neurons was prepared. CGRP-like immunoreactivity was widely distributed in the rat central nervous system. CGRP positive cell bodies were observed in the preoptic area and hypothalamus (medial preoptic, periventricular, anterior hypothalamic nuclei, perifornical area, medial forebrain bundle), premamillary nucleus, amygdala medialis, hippocampus and dentate gyrus, central gray and the ventromedial nucleus of the thalamus. In the midbrain a large cluster of cells was contained in the peripeduncular area ventral to the medial geniculate body. In the hindbrain cholinergic motor nuclei (III, IV, V, VI, VII XII) contained CGRP-immunoreactivity. Cell bodies were also observed in the ventral tegmental nucleus, the parabrachial nuclei, superior olive and nucleus ambiguus. The ventral horn cells of the spinal cord, the trigeminal and dorsal root ganglia also contained CGRP-immunoreactivity. Dense accumulations of fibers were observed in the amydala centralis, caudal portion of the caudate putamen, sensory trigeminal area, substantia gelatinosa, dorsal horn of the spinal cord (laminae I and II). Other areas containing CGRP-immunoreactive fibers are the septal area, nucleus of the stria terminalis, preoptic and hypothalamic nuclei (e.g., medial preoptic, periventricular, dorsomedial, median eminence), medial forebrain bundle, central gray, medial geniculate body, peripeduncular area, interpeduncular nucleus, cochlear nucleus, parabrachial nuclei, superior olive, nucleus tractus solitarii, and in the confines of clusters of cell bodies. Some fibers were also noted in the anterior and posterior pituitary and the sensory ganglia. As with other newly described brain neuropeptides it can only be conjectured that CGRP has a neuroregulatory action on a variety of functions throughout the brain and spinal cord.     

Immunohistochemical localization and biochemical characterization of two novel decapeptides derived from POMC-A in the trout hypothalamus

Several vertebrate species which underwent duplication of their genome, such as trout, salmon and Xenopus, possess two proopiomelanocortin (POMC) genes. In the trout, one of the POMC molecules, called POMC-A, exhibits a unique C-terminal extension of 25 amino acids which has no equivalent in other POMCs characterized so far. This C-terminal peptide contains three pairs of basic residues, suggesting that it may be the source of novel regulatory peptides. The aim of the present study was to investigate the occurrence of these peptides in the brain of the trout Oncorhynchus mykiss by using specific antibodies raised against two epitopes derived from the C-terminal extension of POMC-A, i.e., EQWGREEGEE and YHFQ-NH2. Immunohistochemical labeling of brain sections revealed the presence of EQWGREEGEE- and YHFQ-NH2-immunoreactive cell bodies in the anterior part of the nucleus lateralis tuberis of the hypothalamus. Immunoreactive fibers were observed in the dorsal hypothalamus, the thalamus, the telencephalon, the optic tectum and the medulla oblongata. In contrast, no labeling was detected using antibodies against the non-amidated peptide YHFQG. Biochemical characterization was performed by combining high-performance liquid chromatography (HPLC) analysis with radioimmunoassay (RIA) quantification. Two peptides exhibiting the same retention time as synthetic EQWGREEGEE and ALGERKYHFQ-NH2 were resolved. However, no peptide co-eluting with YHFQ-NH2 or YHFQG could be detected. These results demonstrate that, in the trout brain, post-translational processing of POMC-A generates the two decapeptides EQWGREEGEE and ALGERKYHFQ-NH2. The wide distribution of immunoreactive fibers in the diencephalon, telencephalon, optic tectum and medulla oblongata suggests that these peptides may exert neurotransmitter and/or neuromodulator activities.     

Alpha-melanocyte-stimulating hormone (alpha-MSH) in the brain of the cartilagenous fish. Immunohistochemical localization and biochemical characterization

The distribution of immunoreactive alpha-melanocyte-stimulating hormone (alpha-MSH) in the central nervous system and pituitary of the elasmobranch fish Scyliorhinus canicula was determined by the indirect immunofluorescence and the peroxidase-antiperoxidase methods using a highly specific antiserum. Perikarya containing alpha-MSH-like immunoreactivity were localized in the dorsal portion of the posterior hypothalamus, mainly in the tuberculus posterioris and sacci vasculosus nuclei. Immunoreactive alpha-MSH cell bodies were found in the dorsal wall and ventral region of the caudal part of the tuberculum posterioris. These structures were densely innervated by fine beaded immunoreactive fibers. Some alpha-MSH immunoreactive cells were occasionally detected in the ventral part of the nucleus periventricularis. Scattered cell bodies and fibers were also observed in the dorsal wall of the posterior recess. Outside the hypothalamus very few fibers were detected in the dorsal thalamus and mesencephalon. No immunoreactivity was found in any other parts of the brain. The alpha-MSH immunoreactive material localized in the brain was characterized by combining high-performance liquid chromatography (HPLC) analysis and radioimmunological detection. Brain and pituitary extracts exhibited displacement curves which were parallel to that obtained with synthetic alpha-MSH. The concentrations of alpha-MSH immunoreactive material were determined in 5 different regions of the brain. The highest concentration was found in the hypothalamus. HPLC analysis resolved two major forms of immunoreactive alpha-MSH in the hypothalamus, which had been same retention times as des-N alpha-acetyl-alpha-MSH and its sulfoxide derivative. These results provide the first evidence for the presence of alpha-MSH-like peptides in the fish brain.(ABSTRACT TRUNCATED AT 250 WORDS)     

Thyrotropin-releasing hormone (TRH)-immunoreactive structures in the brain of the domestic mallard

Summary The distribution of immunoreactive thyrotropin-releasing hormone (TRH) in the central nervous system of the domestic mallard was studied by means of the peroxidase-antiperoxidase technique. After colchicine pretreatment, the highest number of TRH-immunoreactive perikarya was found in the parvocellular subdivision of the paraventricular nucleus and in the preoptic region; a smaller number of immunostained perikarya was observed in the lateral hypothalamic area and in the posterior medial hypothalamic nucleus. TRH-immunoreactive nerve fibers were detected throughout the hypothalamus, forming a dense network in the periventricular area, paraventricular nucleus, preoptic-suprachiasmatic region, and baso-lateral hypothalamic area. TRH-containing nerve fibers and terminals occurred in the organon vasculosum of the lamina terminalis and in the external zone of the median eminence in juxtaposition with hypophyseal portal vessels. Scattered fibers were also seen in the internal zone of the median eminence and in the rostral portion of the neural lobe. Numerous TRH-immunoreactive fibers were detected in extra-hypothalamic brain regions: the highest number of immunoreactive nerve fibers was found in the lateral septum, nucleus accumbens, olfactory tubercle, and parolfactory lobe. Moderate numbers of fibers were located in the basal forebrain, dorsomedial thalamic nuclei, hippocampus, interpeduncular nucleus, and the central gray of the mesencephalon. The present findings suggest that TRH may be involved in hypophysiotropic regulatory mechanisms and, in addition, may also act as neuromodulator or neurotransmitter in other regions of the avian brain.     

Topographical localisation of endothelin mRNA and peptide immunoreactivity in neurones of the human brain

Summary The distribution of endothelin mRNA and immunoreactivity in the human brain was investigated using the technique of in situ hybridization and immunocytochemistry. Cryostat sections from 22 cases of neurologically normal adult human brain, collected 3–7 h post-mortem were hybridized with³⁵S-labelled complementary (c)RNA probes prepared from the 3 non-coding region of endothelin-1 cDNA, and the chromosomal genes encoding endothelin-2 and -3. In situ hybridization with all three cRNA probes revealed labelled neuronal cell bodies in laminae III–VI of the parietal, temporal and frontal cortices. Labelled cells were also seen, scattered throughout the para- and periventricular; supraoptic and lateral hypothalamic nuclei, the caudate nucleus, amygdala, hippocampus, basal nucleus of Meynert, substantia nigra, raphe nuclei, Purkinje cell layer of the cerebellum and in the dorsal motor nuclei of the vagus of the medulla oblongata. The distribution of neurones immunoreactive to endothelin was similar to that of endothelin mRNA, although fewer immunoreactive cells throughout the brain, were noted. Immunoreactive fibres were present mainly in the cortex and hypothalamus, and to a lesser extent in the brain stem. Combined in situ hybridization and immunocytochemistry on the same section revealed the presence of endothelin-1 mRNA and immunoreactivity in the same cortical neuronal cell. Colocalisation studies in the cortex revealed endothelin-1 mRNA and immunoreactivity in a number of cells which also expressed neuropeptide Y mRNA and immunoreactivity. In the hypothalamus and basal nucleus of Meynert endothelin immunoreactivity was colocalised to a subset of neurophysin- and galanin-immunoreactive cell bodies respectively. Endothelin mRNA and immunoreactivity was also seen in some blood vessel endothelial cells. The findings of endothelin mRNAs and immunoreactivity in heterogenous neuronal populations further emphasises the potential role of endothelin as a neuropeptide, probably having diverse actions in the nervous system of man.     

Immunocytochemical distribution of FMRFamide-like substance in the brain of the cloudy dogfish,Scyliorhinus torazame

Summary The distribution of the molluscan cardioexcitatory tetrapeptide FMRFamide (Phe-Met-Arg-Phe-NH₂) in the brain of the cloudy dogfish, Scyliorhinus torazame, was examined by immunocytochemistry. FMRFamide-like immunoreactivity was demonstrated to occur extensively in various regions of the dogfish brain, except for the corpus cerebelli. Immunoreactive neuronal perikarya were located in the ganglion of the nervus terminalis, the preoptic area, and the hypothalamic periventricular gray matter consisting of the nucleus medius hypothalamicus, the nucleus lateralis tuberis, and the nucleus lobi lateralis. some of the immunoreactive cells in the hypothalamus were identified as cerebrospinal fluid-contacting neurons. The bulk of the immunostained fibers in the nervus terminalis penetrated into the midventral portion of the telencephalon and ran dorsocaudally toward the basal telencephalon and hypothalamus, showing radial projections or ramifications. The labeled fibers were abundant in the midbasal part of the telencephalon and in the hypothalamus, where some fibers were found in loose networks around the cell bodies of the nucleus septi and hypothalamic periventricular nuclei. The fibers demonstrated in the hypothalamus terminated around the vascular wall of the primary capillary plexus of the median eminence or penetrated deeply into the pars intermedia of the hypophysis. These results suggest that, in the dogfish, an FMRFamide-like substance participates in the regulation of adenohypophysial function. This molecule may have a role as a neurotransmitter and/or neuromodulator in the central nervous system.     

Distribution of a novel avian gonadotropin-inhibitory hormone in the quail brain

We recently identified a novel hypothalamic neuropeptide inhibiting gonadotropin release in the quail brain and termed it gonadotropin inhibitory hormone (GnIH). In this study, we investigated the localization and distribution of GnIH in both sexes of adult quails by immunohistochemistry with a specific antiserum against GnIH and in situ hybridization. Quantitative analysis demonstrated that the concentration of GnIH in the diencephalon was greater than that in the mesencephalon without sex difference. GnIH concentrations in the cerebrum and cerebellum were below the level of detectability. Clusters of GnIH-like immunoreactive (GnlH-ir) cell bodies were localized in the paraventricular nucleus (PVN) of the hypothalamus. There was no significant difference in the number of GnlH-ir cells in the PVN between males and females. By double immunostaining with antisera reacting with GnIH or avian posterior pituitary hormones (vasotocin and mesotocin), GnIH-ir cells were found to be parvocellular neurons in the ventral portion of PVN, which showed no immunoreaction with the antisera against vasotocin and mesotocin. In situ hybridization revealed the cellular localization of GnIH mRNA in the PVN. GnIH-ir nerve fibers were however widely distributed in the diencephalic and mesencephalic regions. Dense networks of immunoreactive fibers were found in the ventral paleostriatum, septal area, preoptic area, hypothalamus, and optic tectum. The most prominent fibers were seen in the median eminence of the hypothalamus and the dorsal motor nucleus of the vagus in the medulla oblongata. Thus, GnIH may participate not only in neuroendocrine functions, but also in behavioral and autonomic mechanisms.     

四种细胞因子在中华蟾蜍脑中的分布

采用免疫组织化学SABC法,研究白介素-1α、干扰素-γ、神经生长因子-β和肿瘤坏死因子-α在成体中华蟾蜍脑中的表达和分布特点。结果发现,白介素-1α阳性细胞数量很多,分布于脑的各个区域。白介素-1α多在细胞的胞体中,而原始海马锥体细胞,中脑的背前侧被盖核和腹后侧被盖核中的细胞可见阳性的突起。干扰素-γ阳性细胞数量较多,分布在端脑的原始海马和隔区,丘脑腹外侧核,下丘脑的视前区、视交叉上核和腹侧漏斗核,中脑被盖的背前侧被盖核、腹前侧被盖核、背后侧被盖核和腹后侧被盖核中,小脑的Purkinje细胞层和延髓的网状核,其中原始海马,背前侧被盖核和背后侧被盖核,视交叉上核,Purkinje细胞层和网状核中的细胞中可见阳性突起。神经生长因子-β阳性细胞数量较少,主要存在于下丘脑的视前区和视交叉上核,中脑被盖的腹前侧被盖核,小脑的Purkinje细胞层和延髓的网状核中,其中视前区、Purkinje细胞层和网状核中细胞可见阳性突起。肿瘤坏死因子-α阳性细胞数量最少,分布范围仅限于中脑被盖背前侧区和延髓的网状核及中缝核,但细胞具有阳性突起。因此,白介素-1α和干扰素-γ在成体动物脑中分布较为广泛,可能是神经细胞生命活动所必需的;而神经生长因子-β和肿瘤坏死因子-α在成体动物脑中分布范围狭窄,其作用可能仅限于脑中的某些特殊区域。     

Distribution of atrial natriuretic factor-like immunoreactivity in the brain of the frog Rana ridibunda

The localization of atrial natriuretic factor (ANF)-like immunoreactivity in the central nervous system of the frog Rana ridibunda was examined by the indirect immunofluorescence technique, using an antiserum against synthetic ANF (Arg101-Tyr126). Immunoreactive cell bodies were principally found in the dorsal and medial pallium, the medial septal nucleus, the ventrolateral and anteroventral areas of the thalamus, the lateral forebrain bundle, the posterolateral thalamic nuclei, the preoptic nucleus, the dorsal infundibular nucleus, and the anteroventral tegmentum nucleus of the mesencephalon. Numerous cell bodies and a very dense fiber bundle were visualized in the interpeduncular nucleus. All the areas mentioned above contained a high density of immunoreactive fibers. In addition, the amygdala, the infundibular nucleus, the median eminence, and most of the areas of the mesencephalon contained a moderate number of ANF-positive nerve processes. In the frog pituitary, fibers and nerve terminals were found in the peripheral zone of the neural lobe. The intermediate and anterior lobes of the frog pituitary were totally devoid of ANF immunoreactivity. These results indicate that ANF-like material is widely distributed in the frog brain and that ANF may be involved in various brain functions including neuroendocrine regulations.     

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.     

Immunoreactive material resembling ovine prolactin in perikarya and nerve terminals of the rat hypothalamus

Summary The presence of prolactin (PRL)-like material is demonstrated in the brain of rats with the aid of anti-ovine PRL (oPRL) IgG as primary antibody in the unlabeled antibody-enzyme method. Immunoreactive deposits are visualized as an intraneuronal constituent with a widespread distribution in the hypothalamus and neural lobe of the pituitary. Dense networks of reactive nerve terminals derived from two prominent fibre tracts, a ventral (VHT) and a dorsal hypothalamo-neurohypophysial tract (DHT) are seen. The VHT is confined to the median eminence and pars oralis tuberis, the DHT to the pars caudalis tuberis. Both fibre tracts pass through the infundibular stalk into the neural lobe. The origin of the immunoreactive nerve terminals can be elucidated only to some extent. The VHT gives off beaded fibres entering the ependymal and glandular layer of the median eminence. Immunoreactive perikarya are observed in the supraoptic nucleus, the paraventricular nucleus, the anterior hypothalamic nucleus, the anterior commissural nucleus, the preoptic nucleus and the interstitial nucleus of the stria terminalis. A few of the immunoreactive perikarya are observed in close connection with brain vessels and the ependymal cells of the third ventricle. The results indicate that the anti-oPRL has a unique region specificity implying that only a segment of the mammalian PRL molecule is present in these nuclei of the brain. Fragments of PRL may function as neuromodulators or neurotransmitters in the rat brain.We are indebted to Dr. Mogens Hammer, Rigshospitalet, Copenhagen for the gift of Arg-VP and anti-VP, and to NIAMDD for the gift of ovine PRL, ratPRL, anti-rPRL, anti-hPRL and bovineSTH     

Immunohistochemical localization of neuropeptide Y-like substance in the brain and hypophysis of the brown hagfish,Paramyxine atami

The distribution of neuropeptide Y-like immunoreactivity in the brain and hypophysis of the brown hagfish, Paramyxine atami, was examined by use of the peroxidase-antiperoxidase method. Immunoreactive cells were found in two areas of the brain, the nucleus hypothalamicus of the diencephalon and the ventrolateral area of the caudal tegmentum, at the level of the nucleus motorius V–VII. The labeled cells of the nucleus hypothalamicus were loosely grouped and recognized as bipolar neurons. Immunolabeled fibers were widely distributed in the brain, showing the highest density in the diencephalon. They were sparse, or absent, in the olfactory bulb, habenula, primordium hippocampi, neurohypophysis, corpus interpedunculare, and dorsolateral area of the medulla oblongata. The fibers appeared to project exclusively from the ventral hypothalamus to various other portions of the brain: the anterolateral areas of the telencephalon via the basal hypothalamus, the pars dorsalis thalami, the dorsocaudal region of the mesencephalon, and the ventromedial portions of the tegmentum and anterior medulla oblongata. These findings suggest that, in the brown hagfish, NPY-like substance is involved in neuroregulation of various cerebral areas, but it may be of little significance in the control of pituitary function.     

Corticotropin-releasing hormone-like immunoreactivity in the brain of the snake Bothrops jararaca

The distribution of corticotropin-releasing hormone in the brain of the snake Bothrops jararaca was studied immunohistochemically. Immunoreactive neurons were detected in telencephalic, diencephalic and mesencephalic areas such as dorsal cortex, subfornical organ, paraventricular nucleus, recessus infundibular nucleus, nucleus of the oculomotor nerve and nucleus of the trigeminal nerve. Immunoreactive fibres ran along the hypothalamo-hypophysial tract to end in the outer layer of the median eminence and the neural lobe of the hypophysis. In general, immunoreactive fibres occurred in the same places of immunoreactive neurons. In addition, immunoreactive fibres were observed in the septum, amygdala, lamina terminalis, supraoptic nucleus, nucleus of the paraventricular organ, ventromedial hypothalamic nucleus and interpeduncular nucleus. These results indicate that, as for other vertebrates, corticotropin-releasing hormone in B. jararaca brain, besides being a releasing hormone, may also act as a central neurotransmitter and/or neuromodulator.