Mapping of neuropeptide Y-like immunoreactivity in the feline hypothalamus and hypophysis

The distribution of neuropeptide Y (NPY) in the cat hypothalamus and hypophysis was studied with the indirect immunofluorescence technique of Coons and co-workers (Coons, Leduc, and Connolly: J. Exp. Med. 102:49-60, 1955), which provided a detailed map of NPY-like immunoreactive neurons. The immunolabelling was detected in cell bodies, fibers, and terminallike structures widely distributed throughout the whole hypothalamus. A large population of medium-sized NPY-like immunoreactive cell bodies was localized in the area of arcuate nucleus. The number of immunoreactive cell bodies visualized was dramatically increased after intracerebroventricular injections of colchicine. Numerous immunolabelled cell bodies were also visible in the median eminence and scattered in the lateral hypothalamic area. Dense plexuses of NPY-immunoreactive fibers were observed in the arcuate nucleus, internal layer of median eminence, periventricular zone, and paraventricular nucleus. Other regions of hypothalamus displaying numerous NPY-like immunoreactive fibers included dorsal and ventrolateral hypothalamic areas. In contrast, certain hypothalamic areas were almost devoid of NPY-like immunoreactive fibers-namely, the mammillary bodies and suprachiasmatic nucleus. Finally, in neurohypophysis, bright immunofluorescent fibers were observed along the pituitary stalk and penetrating the neural lobe. These results suggest the widespread distribution of the NPY-containing neuronal systems in the cat hypothalamus and hypophysis.     

Distribution of neuropeptide Y-like immunoreactivity in the normoganglionic and aganglionic segments of human colon

Summary The localisation and distribution of neuropeptide Y (NPY)-like immunoreactivity were studied by use of immunohistochemical methods in gut tissues from 19 patients with Hirschsprung's disease, including 4 cases of long segment aganglionosis. In the normoganglionic segment, immunoreactive cell bodies and nonvaricose processes were seen within both myenteric and submucous plexuses. A scarce supply of varicose fibres was found in the lamina propria mucosae, muscularis mucosae and longitudinal muscle layer. NPY fibres were more frequently encountered in the circular muscle layer, although with a weakly immunostaining intensity. In addition, blood vessels in the submucosal connective tissue were surrounded by a typical plexus of varicose, NPY-positive fibres. Immunoreactive endocrine cells could be detected in the colonic epithelium. In the aganglionic segment, numerous nerve fasciculi comprising a small to moderate number of NPY fibres with varicosities were observed throughout the entire layer of the colonic wall. A few varicose, NPY-positive fibres were also contained in the relatively large, hypertrophic nerve fasciculi located in the intermuscular zone and submucosal connective tissue. NPY-immunoreactive fasciculi were more densely distributed in the distal aganglionic segment than in the proximal aganglionic one. On the other hand, the distribution of NPY-positive fibres in long segment aganglionosis was quite different from that in short segment type; in cases of long segment type, no immunoreactive nerve fibres were detected within the circular muscle layer of the proximal aganglionic segment near the oligoganglionic segment and only a few fibres were observed within the hypertrophic nerve bundle of the intermuscular zone. The present results suggest that NPY-like immunoreactive nerves in the human colon have a dual origin of intrinsic and extrinsic elements. The origin and nature of extrinsic NPY nerve fibres in the human colon are discussed.     

Subcellular distribution of neuropeptide Y-like immunoreactivity in guinea pig neocortex

Neuropeptide Y-like immunoreactivity (NPY-LI) was enriched in synaptosomal fractions of neocortex, which on lysis yielded vesicle-rich fractions. The distribution of NPY-LI on a sucrose density gradient was similar to that of somatostatin, with a concentration in heavy vesicles. The peptides were not found in light vesicles in contrast to the distribution of noradrenaline. Both homogenate and vesicular NPY-LI coeluted with synthetic NPY on reverse-phase HPLC.     

Diazepam and buspirone alter neuropeptide Y-like immunoreactivity in rat brain

Neuropeptide Y-like immunoreactivity (NPY-LI) was investigated in naIve Sprague-Dawley rats subjected to acute, subchronic (7 days) or chronic (21 days) intraperitoneal treatment with diazepam (1 or 3 mg/kg once daily) or buspirone (1.5 or 5 mg/kg twice daily). NPY-LI was determined by radioimmunoassay in the amygdala, nucleus accumbens, hypothalamus and frontal cortex 24 h after the last dose of the drugs. Amygdala NPY-LI decreased after acute diazepam (3 mg/kg) or buspirone (1.5 mg/kg) and increased after subchronic treatment with both doses of diazepam and after chronic buspirone (1.5 mg/kg) treatment. Both diazepam and buspirone given in subchronic and chronic doses decreased NPY-LI levels in the nucleus accumbens. Hypothalamic NPY-LI changed only after chronic treatment: it decreased after diazepam and increased after buspirone (5 mg/kg). NPY-LI content in the frontal cortex decreased after subchronic diazepam (3 mg/kg) treatment and slightly increased after buspirone. The study has shown that both diazepam and buspirone affect NPY-LI levels in rats. These results suggest that the NPY system in the amygdala and nucleus accumbens is implicated in the anxiolytic effects of the drugs studied.     

Ultrastructural localization of neuropeptide Y-like immunoreactivity in the rat hippocampal formation.

Neuropeptide Y (NPY) has been implicated in the modulation of hippocampal neuronal activity and in the pathophysiology of several neurological disorders involving the hippocampal formation. Thus, this study examines the light and electron microscopic immunoperoxidase labeling of a rabbit polyclonal antibody against porcine NPY in single sections through each lamina of the CA1 and CA3 regions of the hippocampus and the dentate gyrus (DG) of normal adult rats. By light microscopy, the majority of perikarya with intense NPY-like immunoreactivity (NPY-LI) were located in stratum oriens of CA1 and CA3 of the hippocampus and in the hilus of the DG. Fine varicose processes with NPY-LI were found in all layers of the hippocampal formation, but were densest in the outer third of the molecular layer of the DG. The density of NPY-labeling was greater in the ventral portion of the hippocampal formation. By electron microscopy, most NPY-containing perikarya in all three hippocampal regions were: small (8-12 microns) or medium-sized (12-18 microns) and elongated; or medium-sized and round. A dense accumulation of NPY-LI was commonly observed within the individual saccules of Golgi complexes and some rough endoplasmic reticulum in the cytoplasm. Perikarya and dendrites with NPY-LI usually were directly apposed to other neuronal processes (mostly terminals) and lacked astrocytic appositions. The majority of terminals in contact with NPY immunoreactive neurons were unlabeled and synapsed with the shafts of large and small dendrites. In CA1 and CA3 of the hippocampus, the types of synapses formed by the unlabeled terminals were not significantly different; however, more asymmetric synapses than symmetric synapses were formed by the unlabeled terminals on the shafts of small NPY-labeled dendrites in the DG. The terminals with NPY-LI (0.25-1.2 microns) contained many small, clear vesicles and 0-2 large, dense-core vesicles. The types of synapses (i.e., asymmetric and symmetric) and distribution of NPY-labeled terminals on the targets were remarkably similar in each lamina of the hippocampal subregions. The NPY-labeled terminals usually synapsed with one unlabeled perikaryon or dendrite. However, others synapsed either (1) with two unlabeled perikarya or dendrites simultaneously or (2) with one NPY-containing perikaryon or dendrite. Most of the terminals with NPY-LI formed symmetric junctions with the shafts of small (distal) dendrites.(ABSTRACT TRUNCATED AT 400 WORDS)     

Distribution of neuropeptide Y-like immunoreactivity in the hypothalamus of the adult golden hamster

The distribution of neuropeptide Y (NPY)-like immunoreactivity within the hypothalamus of the adult golden hamster was investigated with conventional immunohistochemical techniques. Neuropeptide Y immunoreactive cell bodies were found in greatest numbers in the arcuate nucleus while a few stained perikarya were seen in the internal and subependymal zones of the median eminence. Isolated perikarya were observed in the anterior commissure and supracommissural portion of the interstitial nucleus of the stria terminalis. Immunoreactive axons were located throughout the hypothalamus with the highest concentrations in the subependymal and internal zones of the median eminence, the interstitial nucleus of the stria terminalis, the medial preoptic area, and in the following nuclei: periventricular, suprachiasmatic, paraventricular, perifornical, median preoptic, and arcuate. Moderate to dense plexuses of immunoreactive fibers were observed in the anterior, lateral, and posterior hypothalamic areas and in the infundibular stalk. The supraoptic nucleus and lateral preoptic area displayed a small number of labeled axons whereas the ventromedial nucleus contained only a few fibers. NPY immunoreactive fibers were present in the optic tract and in the dorsomedial aspect of the optic chiasm. Labeled fibers penetrated the ependymal lining of the third ventricle throughout the ventral aspect of the periventricular zone. Additional fibers were observed in the pia lining the ventral aspect of the hypothalamus. This systematic analysis of hypothalamic NPY immunoreactivity in the adult golden hamster suggests that a portion of the labeled fibers display a distribution that is similar to previously described noradrenergic fibers in the hypothalamus.     

The prepubertal ontogeny of neuropeptide Y-like immunoreactivity in the male Meishan pig brain

Neuropeptide Y (NPY) is widely distributed in the mammalian brain and is involved in numerous functions including the control of feeding, growth and reproduction. Therefore, NPY may be an important peptide to study in agricultural species. This study describes the immunohistochemical localization of NPY throughout prepubertal development in the Meishan pig, a Chinese breed known for its superior reproductive characteristics. Brains of animals from gestational day (g) 30 through postnatal day (pn) 50 (duration of pregnancy averaged 114 days) were processed using a standard immunohistochemical technique utilizing a commercially available rabbit anti-porcine NPY antibody. Neuropeptide Y-like immunoreactivity (NPY-IR) in cell bodies and fibers is evident in many areas of the brain at g30, including the basal telencephalon, hypothalamus, mesencephalon, pons, and medulla. Throughout prenatal development, cell bodies containing NPY-IR generally increase in number and distribution in the brain. During postnatal development the number of cell bodies displaying NPY-IR decreases. The arcuate nucleus of the hypothalamus, shows a dramatic reduction in the number of immunoreactive cell bodies between pn1 (day of birth) and pn20, just before weaning. The distribution of NPY-IR in fibers becomes more widespread throughout gestational development, showing a pattern by 8110 that was characteristic of postnatal ages. The intensity of NPY-IR in fibers also increases throughout gestation. Some additional increases in immunoreactivity occur postnatally, especially in the periventricular hypothalamus and the hippocampus. Other brain areas like the caudate nucleus and putamen show decreases in immunoreactivity postnatally. The distribution of NPY-IR in cell bodies and fibers is similar to that seen in other species, including the rat, and supports the hypothesis that NPY participates in controlling feeding, growth and reproduction in the pig.     

Distribution and characterization of neuropeptide Y-like immunoreactivity in the brain of the crested newt

The newt brain represents a simplified model for the increasingly complex vertebrate neuronal organization. The localization of neuropeptide Y-like (NPY-like) containing neurons in the brain of Triturus cristatus was studied by means of indirect immunofluorescence, peroxidase-antiperoxidase, and avidin-biotin techniques using a highly specific antiserum. NPY-like positive cell bodies were observed in several areas, most notably in the telencephalon (primordium hippocampi and amygdaloid complex), the preoptic and suprachiasmatic areas, the hypothalamus, the dorsal thalamus, the tegmentum, and the rhombencephalon (laterolateral grey column and raphe area). Nerve fibres were particularly abundant in the pallium, striatum, septum, amygdaloid, preoptic neuropils, and pars intercalaris diencephali. Bundles of NPY-immunoreactive fibres also were visualized in the dorsal thalamus and in the posterior hypothalamus. The pars intermedia lacked any NPY-like positive fibres. Neuronal processes also were found in the tectum mesencephali and in the body of the cerebellum. A prominent NPY-like fibre network was observed in the octavolateralis. Concentrations of NPY measured by means of a specific radioimmunoassay were threefold higher in the hypothalamus (15.2 +/- 1.3 ng/mg proteins) than in the rhombencephalon (4.9 +/- 0.3) and the mesencephalon (4.3 +/- 0.2). The concentration found in the telencephalon was 2.1 +/- 0.3 ng/mg proteins. Sephadex G-50 gel chromatography of whole brain extracts indicated the presence of high molecular weight forms of NPY-like material in addition to the authentic peptide. Both amphibian and mammalian NPY peptides had an apparent molecular weight of 4,000 daltons, as evidenced by immunoblotting analysis. High-performance liquid chromatography demonstrated, however, that the newt peptide was slightly less hydrophobic than porcine NPY. The present findings indicate that NPY-immunoreactive neurons are widely distributed in the brain of urodeles. Our data indicate that the NPY molecule has been relatively well preserved during evolution.     

Synaptic analysis of amacrine cells with neuropeptide Y-like immunoreactivity in turtle retina

Neuropeptide Y-like immunoreactivity has been localized previously within three classes of amacrine cells in the turtle retina. We have used the avidin-biotin with horseradish peroxidase technique to label these neurons for examination at the ultrastructural level to answer the following questions. Where are the synaptic contacts of these neurons made? What types of neurons are involved pre- and postsynaptically? What is the intracellular distribution of the immunoreactivity? Processes with neuropeptide Y-like immunoreactivity were located primarily within three regions of the inner plexiform layer: stratum 1, stratum 3, and at the border between strata 4 and 5. In all three regions the processes with neuropeptide Y-like immunoreactivity received synaptic contacts from both unlabeled amacrine and bipolar cells, but the majority of the synaptic input in all three regions was from unlabeled amacrine cells. Processes with neuropeptide Y-like immunoreactivity were presynaptic to unlabeled amacrine cells in all three regions, but also formed contacts onto unlabeled bipolar cells in the region between strata 4 and 5. The immunoreactivity within these cells gave rise to a diffuse reaction product that was distributed throughout the cytoplasm and within large vesicles. This localization of neuropeptide Y-like immunoreactivity within large vesicles suggests that this peptide may play a neuromodulatory role. Such a role would be consistent with previous studies of neuropeptides in the turtle retina.     

Distribution of neuropeptide Y-like immunoreactivity in the brain of the lizard Gallotia galloti.

The distribution of neuropeptide Y (NPY)-like immunoreactivity was studied in the brain of the lizard Gallotia galloti, in order to gain insight into the comparative topography of this peptide. Antisera against both NPY and its C-terminal flanking peptide (C-PON) were used, demonstrating a general coexistence of both peptides, as described in other vertebrates. Most NPY-like immunoreactive (NPY-LI) cell bodies were observed in the telencephalon, specifically in various olfactory structures, all cortices, septum, basal ganglia (except for the globus pallidus), the nucleus of the diagonal band of Broca, the amygdaloid complex, and the bed nucleus of the anterior commissure. NPY-LI cells were also seen in the preoptic and hypothalamic regions and the dorsal thalamus (mainly in the perirotundal belt), as well as in the mesencephalic tegmentum (in the ventral tegmental area, the substantia nigra, and the retrorubral area). NPY-LI fibers and terminals were widely distributed in the brain. All visual and auditory neuropiles were densely innervated. Specially dense plexuses were seen in the nucleus accumbens, the ventral pallidum, the suprachiasmatic and ventromedial hypothalamic nuclei, the nucleus medialis thalami, the left habenula, and the central nucleus of the torus semicircularis. Our analysis shows that the distribution of NPY-like immunoreactivity in the forebrain of Gallotia largely resembles that of other vertebrates, whereas differences are mainly observed in the brainstem. The widespread distribution of NPY in the lizard brain suggests several modulatory functional roles, either in local-circuit systems of the forebrain, or in various limbic, neuroendocrine, and sensory pathways.     

Conditioned fear-induced changes in neuropeptide Y-like immunoreactivity in rats: the effect of diazepam and buspirone

The study aimed to investigate the influence of conditioned fear, produced in the passive avoidance test, on neuropeptide Y-like immunoreactivity (NPY-LI) and the effect of anxiolytics on NPY-LI in frightened rats. Rats avoided the dark chamber, where they were previously subjected to electric footshock, and they exhibited increased numbers of defecations and gastric ulcers. Moreover, they showed increased NPY-LI in the amygdala, nucleus accumbens and hypothalamus, and decreased NPY-LI in the frontal cortex. Diazepam (1 or 3 mg/kg) and buspirone (1.5 or 5 mg/kg) dose-dependently inhibited passive avoidance and decreased the numbers of defecations, and they also decreased the number of gastric ulcers. Diazepam reversed while buspirone only attenuated the fear-induced changes in NPY-LI in all regions studied. In the amygdala, the effect of diazepam was dose-dependent. The effect of diazepam on both behaviour and NPY-LI was antagonized by flumazenil (15 mg/kg). Apart from supporting the role of the NPY system in fear and anxiety, the results of this study suggest that NPY is involved in the anxiolytic effects of diazepam and buspirone and that the effect of diazepam is mediated by benzodiazepine receptors.     

Short axon cells of the rat olfactory bulb display NADPH-diaphorase activity, neuropeptide Y-like immunoreactivity, and somatostatin-like immunoreactivity

Several types of short axon cells of the mammalian olfactory bulb have been described after Golgi impregnation. Two of these types have been observed in our material after treatment with the NADPH-diaphorase procedure or after immunohistochemistry for neuropeptide-Y (NPY). The cells stained by the two procedures have similar morphologies and distributions. A less extensive series of observations confirms that similar cells also display somatostatin (SS)-like immunoreactivity. One of these cell types corresponds to the superficial short axon cell of Golgi and electron microscopic studies. The dendrites of this cell lie within the periglomerular region and in the superficial external plexiform layer (EPL), generally lying parallel to the glomerular layer. In some cases the axon has been traced across the EPL into the granule cell layer (GCL). This cell may provide another route of interaction between the periglomerular region and the granule cells in addition to the influences conducted by basal dendrites and axon collaterals of some mitral and tufted cells. A type of deep short axon cell is also visible with these two procedures. It lies deep in the granule cell layer, frequently near the ventricular layer and its dendrites lie parallel to that layer. This deep short axon cell is stained with much greater frequency by the NADPH-diaphorase and NPY procedures than is the superficial short axon cell. It corresponds most closely to the Blanes or Golgi cells of the Golgi impregnation literature, but it appears to differ from these cells in the position and orientation of its dendrites. No spines have been observed on either the superficial or deep cells in this series. Many glomeruli are also stained by the NADPH-diaphorase procedure, but are not NPY or SS immunoreactive. This may provide additional evidence for functional differences between glomeruli in local regions of the olfactory bulb.     

Transient increases in neuropeptide Y-like immunoreactivity in dentate hilar neurons following fimbria/fornix transection

Neurons containing neuropeptide Y (NPY) are numerous in those hippocampal regions that receive septal and monoaminergic afferents. To assess the role of these afferents in the expression of NPY in hippocampal neurons, the number and distribution of perikarya with NPY-like immunoreactivity (NPY-LI) was examined quantitatively in the dentate gyrus of adult male rats following unilateral transection of the right fimbria/fornix. In unlesioned rats, immunoperoxidase labeling for the antibody to NPY was detected mostly in fibers and only a few perikarya in the dentate gyrus. Following fornix transections, the number of detectable NPY-containing neurons in the hilus of the dentate gyrus ipsilateral to the lesion increased at 3 days post-lesion (dpl), peaked at 6 and 9 dpl, then returned to basal levels at 14 dpl and 1 and 6 months post-lesion. This elevation followed a rostral to caudal gradient. No apparent changes were found in the distribution of NPY-labeled neurons at any post-lesion interval studied. Moreover, no significant changes at any of the post-lesion times were found in the number or distribution of neurons with NPY-LI in the hilus of sham lesioned (i.e., ablations of the cortex and anterior hippocampal formation sparing the fornix) rats. The observed increases in the number of hippocampal neurons containing detectable NPY suggests that the cellular levels of this peptide are dependent on pathways travelling through the fornix. The rapid and transient increases in NPY are not due exclusively to changes in cholinergic pathways but may involve changes in other pathways within the fornix or even indirect neurotrophic effects. © 1993 Wiley-Liss, Inc.     

Effect of substituted benzamides on feeding and hypothalamic neuropeptide Y-like immunoreactivity (NPY-LI) in rats

The study was conducted: (i) to evaluate the effects of three substituted benzamides on feeding behaviour in rats with free access to food and in those with access to food limited either to the light or to the dark phase of the diurnal cycle; and (ii) to determine whether the hypothalamic neuropeptide Y (NPY) system is involved in the action of these drugs on feeding. In free-feeding rats, a single dose of eticlopride (1 mg/kg, i.p.) or raclopride (1 mg/kg, i.p.) decreased 24-h food intake, whereas remoxipride (3 mg/kg, i.p.) produced no effect. Single doses of eticlopride and raclopride but not of remoxipride decreased hypothalamic neuropeptide Y-like immunoreactivity (NPY-LI). Eticlopride administered once daily for 14 days decreased both food intake and hypothalamic NPY-LI. When given for 14 days, raclopride and remoxipride decreased food intake in rats with access to food in the dark (19.00-07.00) but not in thelight (07.00-19.00) phase of the diurnal cycle; both these compounds decreased hypothalamic NPY-LI only in the former group of rats. The results suggest that the effects of substituted benzamides on feeding behaviour depend on the drug and the time of administration and that these effects are related to the altered function of the hypothalamic NPY system.     

Somatostatin-, vasoactive intestinal polypeptide- and neuropeptide Y-like immunoreactivity in eye- and submandibular gland-projecting sympathetic neurons

Studies combine the use of the retrograde tracer, fluorogold, and immunocytochemical staining to determine whether superior cervical ganglion (SCG) neurons projecting to the iris or submandibular gland (SMG) in adult male and female rats show distinctive immunoreactivity to somatostatin (SS), vasoactive intestinal polypeptide (VIP), or neuropeptide Y. Overall, more SMG-projecting neurons than eye-projecting neurons contain VIP-like immunoreactivity (VIP-LI), and more eye-projecting neurons than SMG-projecting neurons contain SS-LI and VIP-LI. Thus, postganglionic neurons of the SCG that project to specific target tissues are heterogeneous in their peptide content, and there are differences in the pattern of peptide-immunoreactivity between neurons projecting to these two target tissues. In addition, the results indicate that there may be gender differences in the expression of these neuropeptides.     

Diurnal rhythm of neuropeptide Y-like immunoreactivity in the suprachiasmatic, arcuate and paraventricular nuclei and other hypothalamic sites

The diurnal rhythm of neuropeptide Y (NPY)-like immunoreactivity was examined in 9 discrete hypothalamic sites of rats maintained on a 12:12 h light/dark cycle. Significant bimodal rhythms of NPY concentration were detected in the suprachiasmatic and arcuate nuclei, with significant peaks just prior to onset of the nocturnal period and also at onset of the light period. In the parvocellular division of the paraventricular nucleus, a unimodal NPY peak was observed prior to dark onset. No diurnal rhythm was seen in the magnocellular division of the paraventricular nucleus, nor in 5 other hypothalamic areas examined.     

Somatostatin- and neuropeptide Y-like immunoreactivity in the dentate area, hippocampus, and subiculum of the domestic pig.

With the principal aim of providing baseline observations for future experimental studies, the distribution of somatostatin-like and neuropeptide Y-like immunoreactivities is described in the dentate area, hippocampus, and subiculum of the domestic pig (Sus scrofa domesticus) and compared with the distribution described in other mammals. Intensely stained somatostatin-like immunoreactive nerve cell bodies were present throughout the region, with highest densities in the dentate hilus, stratum radiatum and stratum oriens of the hippocampal regio inferior, stratum oriens of the hippocampal regio superior, and in the subicular cell layer. Somatostatin-like immunoreactive terminals were represented by both stained fibers and stained puncta. Scattered somatostatin-like immunoreactive nerve fibers were seen in most areas, but regular fiber plexuses were present in the dentate molecular layer and dentate hilus, stratum moleculare of the hippocampus, and in the subicular plexiform layer. Somatostatin-like immunoreactive puncta were seen in the dentate molecular layer, stratum moleculare of the hippocampus, and in the subicular plexiform layer. Neuropeptide Y-like immunoreactive nerve cell bodies were less numerous than somatostatin-like immunoreactive ones. They were mainly seen in the dentate granule cell layer and dentate hilus, stratum radiatum and stratum oriens of the hippocampus, and in the subicular cell layer. Intensely stained neuropeptide Y-like immunoreactive fibers were numerous, and present in all areas examined. They formed fiber plexuses in the dentate molecular layer and dentate hilus, stratum moleculare of the hippocampal regio superior, and in the subicular plexiform layer. Neuropeptide Y-like immunoreactive puncta were present in the dentate molecular layer, stratum moleculare of the hippocampus, and in the subicular plexiform layer. Consistent and very characteristic variation in the distribution of somatostatin-like and neuropeptide Y-like immunoreactivity was found along the septotemporal axis of the hippocampus. The distribution of somatostatin-like and neuropeptide Y-like neurons and terminals in the domestic pig displayed striking similarities with the basic pattern of organization of these neuropeptides in other species, although more subtle species-specific characteristics were also observed in the pig.     

Distribution of neuropeptide Y-like immunoreactivity and its relationship to FMRF-amide-like immunoreactivity in the sixth lumbar and first sacral spinal cord segments of the rat

The present study was aimed at describing the distribution of neuropeptide Y (NPY)-like immunoreactivity in the sixth lumbar (L6) and first sacral segments (S1) of the rat spinal cord, comparing this distribution to that of FMRF-amide-like immunoreactivity and determining whether NPY- and FMRF-amide-like immunoreactivities are present in the same neurons in the dorsal gray commissure (DGC) in L6 and S1 of the rat spinal cord. For distribution studies tissue from colchicine-treated animals was processed according to the peroxidase-antiperoxidase technique using anti-NPY as the primary antiserum. For co-localization studies serial 5-micron sections were processed for immunofluorescence. Adjacent sections were incubated with either anti-NPY or anti-FMRF-amide as the primary antiserum. The number of immunoreactive cells per section was counted and each section was photographed. The sections were then restained with the other antiserum (i.e., tissue first stained with anti-NPY was stained with anti-FMRF-amide and vice versa), the number of cells per section was recounted, and the sections were rephotographed. NPY-like immunoreactive cells and fibers were identified in the DGC, sacral parasympathetic nucleus, substantia gelatinosa, marginal zone, nucleus proprius, and ventral horn. Every cell in the DGC that contained NPY-like immunoreactivity was found also to contain FMRF-amide-like immunoreactivity, and the distribution of NPY-like immunoreactive fibers was found to be similar, although denser than FMRF-amide-like immunoreactive fibers. The distribution of NPY-like immunoreactivity in L6 and S1 of the rat spinal cord suggests that an NPY-like peptide may be involved in regulation of pelvic viscera, processing of primary afferent information, and motor regulation of pelvic muscles. The presence of NPY- and FMRF-amide-like immunoreactivities in the same neurons in the DGC together with the lack of bona fide FMRF-amide in the rat central nervous system, the presence of NPY in the rat central nervous system, and the cross-reactivity of anti-FMRF-amide with NPY support the hypothesis that the FMRF-amide antiserum recognizes an NPY-like peptide in the rat spinal cord.     

Distribution of nestin immunoreactivity in the normal adult human forebrain

The distribution of nestin immunoreactivity was studied in the whole normal adult human forebrains using new anti-human nestin mouse monoclonal and rabbit polyclonal antiserum. The nestin immunoreactive cells could be divided into three types according to their morphological characteristics. The first type contained neuron-like nestin immunoreactive cells, distributed in CA1–3 of hippocampus, septum, the nucleus of diagonal band, amygdala and basal nucleus of Meynert. The second type contained astrocyte-like cells, distributed in the subependymal zone and subgranular layer of dentate gyrus. The third type of cells had smaller cell bodies and fewer processes, also distributed in the subependymal zone and subgranular layer of dentate gyrus. Double immunohistochemical staining showed that the nestin positive, neuron-like cells in the nucleus of diagonal band and hippocampus also expressed NSE. However, the astrocyte-like nestin immunoreactive cells of the subependymal zone and subgranular layer of dentate gyrus were not double labeled with GFAP. Although some nestin immunoreactive fibers were distributed in the infundibulum, no nestin-immunoreactive cells were detected in the cortex. These data indicate that nestin exist in the adult human brain outside of the subependymal zone and dentate gyrus and also implies that nestin-immunoreactive cells may play a role in the modulation of basal forebrain function.     

Effects of haloperidol and clozapine on neuropeptide Y-like immunoreactivity in the nucleus accumbens and striatum of rats pretreated with psychostimulants

It has been shown that the synthesis, release and levels of neuropeptide Y (NPY), a peptide linked to the dopamine system, are altered by stimulants with psychotomimetic properties and by antipsychotic drugs. This study was designed to evaluate the effect of 3-day haloperidol (HAL) (2 mg/kg i.p.) or clozapine (CLOZ) (25 mg/kg i.p.) treatment on neuropeptide Y-like immunoreactivity (NPY-LI) in nucleus accumbens and striatum (caudate-putamen) in rats pretreated with d-amphetamine or phencyclidine. D-amphetamine (5 mg/kg s.c. twice daily for 6 days and once on day 7) and phencyclidine (10 mg/kg i.p. once daily for 2 days and 15 mg/kg once on day 3) induced marked stereotypy with different symptomatology. Stereotypy is thought to resemble psychosis-related behavior. The first dose of either HAL or CLOZ was given 3 or 2h after the final d-amphetamine or phencyclidine injection, respectively. The control groups were injected with either saline alone, saline instead of psychostimulants, which was followed by antipsychotics, or psychostimulants followed by saline. Rats were sacrificed 24h after antipsychotics or 72 h after the last psychostimulant dose. Both psychostimulants similarly reduced nucleus accumbens and striatal NPY-LI. In saline-pretreated rats, HAL and CLOZ decreased nucleus accumbens NPY-LI, but only HAL decreased striatal NPY-LI. In both the structures examined the effects of HAL and d-amphetamine on NPY-LI were additive. HAL slightly enhanced but CLOZ reversed the phencyclidine-induced decrease in accumbens NPY-LI. The present study has shown that HAL and CLOZ produce different effects on nucleus accumbens and striatal NPY-LI in d-amphetamine or phencyclidine pretreated rats, and it suggests that these effects are related particularly to the dopaminergic and glutamatergic systems whose activities were altered by psychostimulants.