Galanin is Co‐Expressed with Substance P,Calbindin and Corticotropin‐Releasing Factor (CRF) in The Enteric Nervous System of the Wild Boar (Sus scrofa) Small Intestine

Galanin is a neuropeptide widely present in the enteric nervous system of numerous animal species and exhibiting neurotransmittery/neuromodulatory roles. Colocalization patterns of galanin with substance P (SP), corticotropin‐releasing factor (CRF) and calbindin were studied in the small intestine of the wild boar using immunofluorescence technique. We demonstrated the presence of SP in substantial populations of galanin‐immunoreactive (IR) submucous neurons. Additionally, different amounts of nerve fibres exhibiting simultaneous presence of galanin and SP were noted in the small intestinal smooth musculature, submucous ganglia, lamina muscularis mucosae and mucosa. In the wild boar duodenum, jejunum and ileum, the co‐expression of galanin and calbindin was limited to minor populations of submucous neurons only. Single galanin‐/CRF‐IR nerve fibres were exclusively present in the duodenal and jejunal (but not ileal) mucosa. These results strongly suggest that galanin participates in neuronal control of the wild boar small intestine also by functional co‐operation with other biologically active neuropeptides.     

Distribution of orexin B and its relationship with GnRH in the pig hypothalamus

Increasing evidence suggests that orexins--hypothalamic neuropeptides--act as neurotransmitters or neuromediators in the brain, regulating autonomic and neuroendocrine functions. Orexins are closely associated with gonadotropin-releasing hormone (GnRH) neurons in the preoptic area and alter luteinizing hormone (LH) release, suggesting that they regulate reproduction. Here, we investigated the distribution of orexin B (immunohistochemical technique) and the relationship between orexin B and GnRH containing fibres and neurons in the pig hypothalamus using double immunofluorescence and laser-scanning confocal microscopy. Orexin B immunoreactive neurons were mainly localized in the perifornical area (PeF), dorsomedial hypothalamic nucleus (DMH), zona incerta (ZI) and the posterior hypothalamic area (PH), with a sparser distribution in the preoptic and anterior hypothalamic area. Immunoreactive fibres were distributed throughout the central nervous system. Approximately 30% GnRH neurons were in close contact with orexin B immunoreactive fibres, among these approximately 6% of GnRH neurons co-localized with orexin B perikarya in the region between the caudal preoptic area and the anterior hypothalamic area. Orexin B may regulate reproduction by altering LH release in the hypothalamus.     

Concentration and Distribution of Neuropeptide Y, Galanin, β-endorphin, Vasoactive Intestinal Peptide and Gonadotrophin-Releasing Hormone in the Hypothalamus of Gilts during Oestrogen-Induced Surge Secretion of Luteinizing Hormone

Contents The relationship of neuropeptide Y (NPY), galanin (GAL), β-endorphin (β-END) and vasoactive intestinal peptide (VIP) to GnRH neurons were determined during the estradiol-induced LH surge. In experiment 1, 16 ovariectomized (OVX) gilts received 15 μg estradiol benzoate (EB)/kg BW at 0800 h and were slaughtered at either 24 h (n = 5), 48 h (n = 6) or 72 h (n = 5) later and five were injected with corn oil vehicle (0 h controls). Concentrations of neuropeptides were determined in tissue extracts by RIA. In experiment 2, nine OVX gilts were injected with EB as in experiment 1 and killed at either 24, 48 or 72 h (n = 3) later and three were not injected with EB (0 h controls). Frozen sections were processed to localize neuropeptides. In experiment 1, all measured neuropeptides were highest in pituitary stalk median eminence (SME). The GnRH concentration was not different at any time point in medial basal hypothalamus (MBH), preoptic area (POA) or SME. The NPY content in MBH was lower at 24, 48 and 72 h after EB than at 0 h (p < 0.001), and lower in SME at 48 and 72 h than at 24 h (p < 0.05) and 0 h (p < 0.01), respectively. Concentration of GAL in SME was four times higher at 72 h than at 0, 24 or 48 h (p < 0.001). The VIP concentration increased in POA (p < 0.05) and MBH (p < 0.001) at 24 h and 72 h (p < 0.05). Concentration of VIP in SME was lower at 24 and 48 h than at 0 h (p < 0.05) and increased to more than twice (p < 0.05) by 72 h. Concentrations of β-END were not different at any time point in POA and MBH but the highest content of β-END in SME occurred at 24 h (p < 0.001). In experiment 2 a moderate number of GnRH-immunoreactive (IR) fibres were found in the periventricular area of the POA and in organum vasculosum of the laminae terminalis (OVLT). The GnRH-IR fibres formed networks in the external and internal layer of the median eminence (ME). At 24 h, GnRH-IR neurons and fibres in the POA and ME were more numerous and noticeable differences were found in the arcuate nucleus (ARC) and ventromedial nucleus (NVM). At 48 and 72 h, numbers of IR neurons and fibres were higher in the ARC and NVM, but no changes occurred in the POA and ME. The ARC contained a moderate number of NPY-IR fibres, but less numerous small cell bodies. Only a few NPY-IR perikarya and fibres were in the NVM and fibre density was similar at all times after EB injection. VIP-IR fibres were scarcely distributed mostly in the posterior POA and the internal layer of ME. The number of VIP-IR fibres was similar at all time points and regions. A moderate number of varicose β-END fibres supplied the POA, and they were especially dense near the OVLT, but the cell bodies were moderate in number and did not show strong immunoreactivity. In ME, ARC and NVM, the number of β-END immunoreactive structures was greater at 24 and 48 h than at 0 h. The number of β-END-IR nerve fibres in POA was higher at 72 h than at 0 h. Levels of all neuropeptides studied were similar in the POA and MBH and content of NPY, GAL and β-END was very high in the SME of the pig forebrain. The dynamic changes of NPY, GAL, VIP and β-END content in pig hypothalamus during the oestrogen-induced negative and positive feedback phases of LH secretion indicate their potential role in modulating GnRH release from the median eminence.     

鸡脑催乳素免疫反应神经元的分布

运用ＡＢＣ法观察了催乳素（ＰＲＬ）免疫反应神经元在鸡脑的分布。结果,ＰＲＬ阳性胞体主要分布在视交叉上核、视前室旁核、视上核、下丘脑室旁核、弓状核和伏隔核,旧纹状体、正中隆起存在大量阳性纤维末梢,在侧脑室腹侧的室管膜和脑基底神经胶质板上也存在ＰＲＬ阳性神经元。视前室旁核、视交叉上核、下丘脑室旁核、弓状核等核团内的ＰＲＬ阳性神经元有突起向第三脑室投射,伏隔核内及侧脑室室管膜上的ＰＲＬ阳性神经元有突起伸至侧脑室,视上核的ＰＲＬ阳性神经元也有突起投射至脑基底神经胶质板,表明鸡脑内的ＰＲＬ可以释放入脑室系统,参与调节脑－脑脊液神经体液回路。     

Neuropeptide Y in the brain and retina of the adult teleost gilthead seabream (Sparus aurata L.)

The presence of neuropeptide Y (NPY) in the brain and retina of gilthead seabream (Sparus aurata L.) was investigated for the first time. For this investigation we employed an immunoperoxidase technique and the western immunoblot analysis using an antiserum raised against porcine NPY. The results showed that NPY-immunoreactivity was widely distributed in the brain of S. aurata. In particular, we have found NPY-immunoreactive (ir) neurons in the area ventralis telencephali pars centralis and pars lateralis, in the area dorsali telencephali pars centralis subdivision two and in nucleus intermedius thalami. An intense NPY-ir was detected in the telencephalon, in the optic tectum, in the thalamus, hypothalamus and in the vagal lobes. Scarce positive fibres were seen in the olfactory bulbs. NPY-ir amacrine cells were observed in the retina. The western immunoblot analysis revealed a protein band with a mobility corresponding to that of synthetic NPY. Our findings are, in general, in agreement with those obtained in other teleosts. The extensive distribution of NPY indicates for this peptide a key role in basic physiological actions, including visual and gustatory inputs processing.     

Immunohistochemical properties of motoneurons supplying the trapezius muscle in the rat

Combined retrograde tracing (using fluorescent tracer Fast blue) and double-labelling immunofluorescence were used to study the distribution and immunohistochemical characteristics of neurons projecting to the trapezius muscle in mature male rats (n = 9). As revealed by retrograde tracing, Fast blue-positive (FB+) neurons were located within the ambiguous nucleus and accessory nucleus of the grey matter of the spinal cord. Immunohistochemistry revealed that nearly all the neurons were cholinergic in nature [choline acetyltransferase (ChAT)-positive]. Retrogradely labelled neurons displayed also immunoreactivities to calcitonin gene-related peptide (CGRP; approximately 60% of FB+ neurons), nitric oxide synthase (NOS; 50%), substance P (SP; 35%), Leu5-Enkephalin (LEnk; 10%) and vasoactive intestinal polypeptide (VIP; 5%). The analysis of double-stained tissue sections revealed that all CGRP-, VIP- and LEnk-immunoreactive FB+ perikarya were simultaneously ChAT-positive. The vast majority of the neurons expressing SP- or NOS-immunoreactivity were also cholinergic in nature; however, solitary somata were ChAT-negative. FB+ perikarya were surrounded by numerous varicose nerve fibres (often forming basket-like structures) immunoreactive to LEnk or SP. They were also associated with some CGRP-, NOS- and neuropeptide Y-positive nerve terminals.     

Mapping of Neurotensin in the Alpaca (Lama pacos) Brainstem

We studied the distribution of cell bodies and fibres containing neurotensin (NT) in the brainstem of the alpaca using an indirect immunoperoxidase technique. Immunoreactive fibres were widely distributed throughout the brainstem, whereas the distribution of cell bodies was less widespread. Immunoreactive perikarya were only found in the mesencephalic and bulbar reticular formation, periaqueductal grey, nucleus of the solitary tract, laminar spinal trigeminal nucleus and in the inferior colliculus. A high density of fibres containing NT was found in the dorsal nucleus of the raphe, marginal nucleus of the brachium conjunctivum, locus coeruleus, inferior colliculus, inter‐peduncular nucleus, substantia nigra, periaqueductal grey, reticular formation of the mesencephalon, pons and medulla oblongata, nucleus of the solitary tract, laminar spinal trigeminal nucleus, hypoglossal nucleus, inferior central nucleus and in the tegmental reticular nucleus. The widespread distribution indicates that NT might be involved in multiple physiological actions in the alpaca brainstem; this must be investigated in the future as alpacas lives from 0 m above sea level to altitudes of up 5000 m and hence the involvement of this neuropeptide in special and unique regulatory physiological mechanisms could be suggested.     

Glycomolecule Modifications in the Seminiferous Epithelial Cells and in the Acrosome of Post‐testicular Spermatozoa in the Alpaca

A lectin histochemical investigation of the seminiferous epithelium and acrosomes of spermatozoa present in the efferent ductules and epididymal regions was carried out in the alpaca. The histochemical characterization was performed using a battery of different lectins: Con‐A, UEA‐I, LTA, WGA, GSA‐IB4, SBA, PNA, ECA, DBA, MAL‐II and SNA. Sialidase digestion and deglycosilation pre‐treatments were also employed. The cytoplasm of the Sertoli cells contained N‐linked oligosaccharides with α‐d ‐Man/α‐d ‐Glc and GlcNAc and O‐linked glycans with α‐l ‐Fuc, β‐GalNAc, β‐d ‐Gal‐(1‐4)‐d ‐GlcNAc, α–Gal and Neu5Acα2,6α‐GalNAc moieties whereas β‐d ‐Gal‐(1‐3)‐d ‐GalNAc residues were included in both O‐ and N‐glycoproteins. Spermatogonia expressed α‐d ‐Man/α‐d ‐Glc residues included in N‐glycoproteins and α‐Fuc in O‐glycoproteins. Spermatocytes contained the N‐glycoproteins residues α‐d ‐Man/α‐d ‐Glc and GlcNAc and the O‐glycoproteins residues α‐l ‐Fuc, β‐d ‐Gal‐(1‐4)‐d ‐GlcNAc, α–Gal, β‐GalNAc, Neu5Acα2,6α‐GalNAc and Neu5Acα2,6β‐d ‐Gal‐(1‐3)‐d ‐GalNAc. The results of the present study show differences in the presence and distribution of lectin reactive sites throughout the acrosomal development in the alpaca. In particular, Fuc moieties were found only during the Golgi‐phase of spermatids, α‐Gal were found in the acrosome of Golgi‐ and cap‐phase spermatids, sialic‐acid/α‐GalNAc sequence was revealed during the cap‐phase and elongated spermatids, and α‐d ‐Man/α‐d ‐Glc and GlcNAc were detected only in the acrosomes of elongated spermatids. Finally, β‐GalNAc, β‐d ‐Gal‐(1‐3)‐d ‐GalNAc and β‐d ‐Gal‐(1‐4)‐d ‐GlcNAc were added to acrosomal glycoproteins in the early stages of spermatogenesis and remained unchanged during the later phases. Differences in the carbohydrate expression were also demonstrated on the sperm acrosomes during passage through the post‐testicular ducts.     

Distribution of Neurotensin and Somatostatin‐28 (1–12) in the Minipig Brainstem

Using an indirect immunoperoxidase technique, an in depth study has been carried out for the first time on the distribution of fibres and cell bodies containing neurotensin and somatostatin‐28 (1–12) (SOM) in the minipig brainstem. The animals used were not treated with colchicine. The distribution of neurotensin‐ and SOM‐immunoreactive fibres was seen to be quite similar and was moderate in the minipig brainstem: a close anatomical relationship between both neuropeptides was observed. The distribution of cell bodies containing neurotensin or SOM was quite different and restricted. Cell bodies containing neurotensin were found in four brainstem nuclei: nucleus centralis raphae, nucleus dorsalis raphae, in the pars centralis of the nucleus tractus spinalis nervi trigemini and in the nucleus ventralis raphae. Cell bodies containing SOM were found in six nuclei/regions of the brainstem: nucleus ambiguus, nucleus dorsalis motorius nervi vagus, formatio reticularis, nucleus parabrachialis medialis, nucleus reticularis lateralis and nucleus ventralis raphae. According to the observed anatomical distribution of the immunoreactive structures containing neurotensin or SOM, the peptides could be involved in sleep‐waking, nociceptive, gustatory, motor, respiratory and autonomic mechanisms.     

Integration Between Different Hypothalamic Nuclei Involved in Stress and GnRH Secretion in the Ewe

This study investigated possible integrated links in the neuroanatomical pathways through which the activity of neurones in the paraventricular nucleus and arcuate nucleus may modulate suppression of gonadotrophin‐releasing hormone (GnRH) secretion during stressful situations. Double‐label immunofluorescence and laser scanning confocal microscopy were used to examine the hypothalamic sections from the follicular phase ewes. Noradrenergic terminals were in close contact with 65.7 ± 6.1% corticotrophin‐releasing hormone (CRH) and 84.6 ± 3.2% arginine vasopressin (AVP) cell bodies in the paraventricular nucleus but not with β‐endorphin cell bodies in the arcuate nucleus. Furthermore, γ‐amino butyric acid (GABA) terminals were close to 80.9 ± 3.5% CRH but no AVP cell bodies in the paraventricular nucleus, as well as 60.8 ± 4.1%β‐endorphin cell bodies in the arcuate nucleus. Although CRH, AVP and β‐endorphin cell terminals were identified in the medial pre‐optic area, no direct contacts with GnRH cell bodies were observed. Within the median eminence, abundant CRH but not AVP terminals were close to GnRH cell terminals in the external zone; whereas, β‐endorphin cells and terminals were in the internal zone. In conclusion, neuroanatomical evidence is provided for the ewe supporting the hypothesis that brainstem noradrenergic and hypothalamic GABA neurones are important in modulating the activity of CRH and AVP neurones in the paraventricular nucleus, as well as β‐endorphin neurones in the arcuate nucleus. These paraventricular and arcuate neurones may also involve interneurones to influence GnRH cell bodies in medial pre‐optic area, whereas the median eminence may provide a major site for direct modulation of GnRH release by CRH terminals.     

The Distribution and Chemical Coding of Intramural Nerve Structures Supplying the Porcine Stomach

The present study investigated the arrangement and chemical coding of intramural nerve structures supplying the porcine stomach. Tissue samples comprising all layers of the wall of the ventricular fundus were collected from juvenile female pigs (n = 4), which were first deeply anaesthetized and then transcardially perfused with buffered paraformaldehyde. The cryostat sections were processed for double‐labelling immunofluorescence to study the distribution of the intramural nerve structures (visualized with antibodies against protein gene‐product 9.5) and their neurochemical characteristics using antibodies against vesicular acetylcholine transporter (VAChT), nitric oxide synthase (NOS), galanin (GAL), vasoactive intestinal‐polypeptide (VIP), somatostatin (SOM) and substance P (SP). The study confirmed the presence of three distinct nerve plexuses within the wall of the porcine stomach including one myenteric plexus and two, outer and inner, submucous plexuses. The outer and inner submucous plexuses (OSP and ISP, respectively) were similar in respect to the chemical coding of neurons they contained. Most of the neurons expressed immunoreactivity to SP (ISP 58%; OSP 60%) or to VAChT (ISP 56%; OSP 56%), some of them stained for GAL (ISP 18%; OSP 15%) and solitary nerve cells were SOM‐positive (in ISP only). No neurons in the submucous plexuses displayed immunoreactivity to VIP or NOS. In the myenteric plexus, some neurons stained for NOS (20%), VAChT (15%), GAL (10%), VIP (8%) or SP (8%) while no neurons immunoreactive for SOM were encountered. In both submucous and myenteric plexuses, many varicose nerve fibres expressed immunoreactivity to VAChT, GAL or SP, while VIP‐, SOM‐ or NOS‐positive nerve terminals were less numerous. The comparison of the present results with those obtained by other authors has revealed distinct inter‐species differences regarding the arrangement and chemical coding of nerve structures supplying the mammalian stomach.     

Long-term estradiol-17β administration decreases the number of neurons in the caudal mesenteric ganglion innervating the ovary in sexually mature gilts

The effect of estradiol-17β (E(2)) on the number and distribution of neurons in the caudal mesenteric ganglion (CaMG) supplying the ovary of adult pigs was investigated. Also, the numbers of ovarian dopamine-β-hydroxylase (DβH-), neuropeptide Y (NPY-), somatostatin (SOM-), galanin (GAL-) and estrogen receptor (ER)-immunoreactive perikarya as well as the density of the intraganglionic nerve fibers containing DβH and/or NPY, SOM, GAL were determined. E(2) was administered i.m. from day 4 of the first studied estrous cycle to the expected day 20 of the second studied cycle. Injections of E(2) (1) increased the E(2) level in the peripheral blood approximately 4-5 fold, (2) decreased the number of small-sized Fast Blue-positive postganglionic neurons in the CaMG, (3) decreased the number of small perikarya in the ventral, dorsal and central regions of the CaMG, (4) decreased the number of large perikarya in the dorsal and central regions, (5) decreased the number of small and large perikarya in the CaMG that were DβH(+)/NPY(+), (6) decreased the number of small DβH(+) but NPY(-) perikarya, (7) decreased the number of small perikarya coded DβH(+)/SOM(+) and DβH(+)/SOM(-), (8) decreased the number of small DβH(+)/GAL(-) perikarya, (9) decreased the number of small and large perikarya expressing ER subtypes α and β and (10) decreased the total number of nerve fibers in the CaMG containing DβH and/or NPY and DβH and/or GAL. These results show that long-term E(2) treatment of adult gilts downregulates the populations of both noradrenergic and ERs expressing ovarian neurons in the CaMG. Our findings suggest also that elevated E(2) levels that occur during pathological states may regulate gonadal function(s) by affecting ovary supplying neurons.     

Immunohistochemical Localization of Galanin in Bovine Reproductive Organs

The vagina, uterus and oviduct were shown to receive galanin immunoreactive (GAL-IR) nerve fibres, the number of which varied between particular organs. In the ovary, GAL-IR nerves were absent. A small number of these nerves were located in the layers of the oviduct. A moderate number of GAL-IR nerves were situated in the body and uterine horns, whereas the uterine cervix and vagina wall contained a large number of GAL-IR nerve fibres, evenly distributed throughout particular membranes of the organs. GAL-IR nerves were found to contain, simultaneously, either vasoactive intestinal polypeptide (VIP), substance P (SP) or Leu⁵-enkephalin (ENK). Many of the GAL-IR nerves contained tyrosine hydroxylase (TH). A group of GAL-IR nerves that did not possess immunoreactivity to VIP, SP, ENK or TH was also observed.     

Immunohistochemical characterization of neurons in the porcine ciliary ganglion

The present study was aimed at disclosing the chemical coding of nerve structures in the porcine ciliary ganglion (CG) using immunohistochemical methods. The substances under investigation included markers of "classical" neurotransmitters, choline acetyltransferase (ChAT), vesicular acetylcholine transporter (VAChT), tyrosine hydroxylase (TH) and dopamine beta-hydroxylase (DbetaH) as well as neuropeptides, somatostatin (SOM), galanin (GAL), substance P (SP), calcitonin gene-related peptide (CGRP), vasoactive intestinal polypeptide (VIP) and neuropeptide Y (NPY). Immunoreactivity to ChAT and VAChT was found virtually in all the neuronal somata and in numerous intraganglionic, varicose nerve fibres which often formed basket-like formations around the nerve cell bodies. Many CG neurons contained immunoreactivity for SOM (46%) or GAL (29%). Interestingly, a small number (approx. 1%) of the cholinergic somata stained for TH but not for DbetaH; nevertheless, some extra- and intraganglionic nerve fibres displayed immunoreactivity for DbetaH or TH. The CG perikarya stained neither for vasoactive intestinal polypeptide (VIP) nor for neuropeptide Y (NPY), but some NPY- or VIP-positive nerve terminals were observed within nerve bundles distributed outside the ganglion. SP- and CGRP-immunoreactivity was found in some intraganglionic nerve fibres only. The present study revealed that the porcine CG consists of cholinergic neurons many of which contain SOM and GAL. Thus, it can be assumed that in the pig, these neuropeptides are involved, complementary to acetylocholine, in the parasympathetic postganglionic nerve pathway to structures of the eye including the ciliary and iris sphincter muscles.     

The distribution and chemical coding of neurons in the celiac-superior mesenteric ganglion complex supplying the normal and inflamed ileum in the pig

The present study investigated the chemical coding of neurons in the celiac-superior mesenteric ganglion complex supplying the normal (n=4) and inflamed (n=4) ileum (chemically-induced inflammation) in juvenile pigs using retrograde tracing combined with immunohistochemistry. Ileum-projecting neurons (IPN) were predominantly distributed in the left and right superior mesenteric pools of the ganglion. The majority of them were adrenergic (tyrosine hydroxylase-positive) and also contained neuropeptide Y, somatostatin or galanin. No clear-cut differences in the distribution and chemical coding of IPN were found between normal and inflamed pigs. However, in the inflamed group, the density of peptidergic, IPN-associated nerve fibres was higher than that found in the control group.     

Distribution of Prosaposin mRNA in the Central Nervous System of the Pigeon (Columba livia)

Bioassay and immunohistochemical studies have detected the presence of prosaposin in the central nervous system (CNS) of mammals. Here, first time, we have determined the partial cDNA sequence of pigeon prosaposin and mapped the distribution of its mRNA in the pigeon CNS. The predicted amino acid sequence of pigeon prosaposin showed 93 and 60% identity to chicken and human prosaposin, respectively. In situ hybridization, autoradiograms showed that the prosaposin mRNA expression was found in the olfactory bulb, prepiriform cortex, Wulst, mesopallium, nidopallium, hippocampal formation, thalamus, tuberis nucleus, pre‐tectal nucleus, nucleus mesencephalicus lateralis, pars dorsalis, nucleus isthmi, pars parvocellularis and magnocellularis, Edinger–Westphal nucleus, optic tectum, cerebellar cortex and nuclei, vestibular nuclei and gray matter of the spinal cord. These results suggest that the cDNA sequence of pigeon prosaposin is comparable to other vertebrates, and the general distribution pattern of prosaposin mRNA resembles those are found in mammals.     

Neurochemical properties of aquaporin 1-expressing sensory neurons from the ovine trigeminal ganglion

Aims of the present study were to investigate the distribution and morphology of aquaporin 1-immunoreactive (AQP1-IR) neurons in the sensory ganglia of the sheep. Double immunohistochemical staining was applied to figure out whether substance P (SP), calcitonin gene-related peptide (CGRP) and galanin are present in AQP1-bearing primary afferent neurons. The expression of AQP1 was present only in trigeminal ganglion, whereas in nodose ganglion, jugular ganglion as well as C(1) -C(7) dorsal root ganglia no presence of AQP1 was found. In trigeminal ganglion, 15.4 ± 2.3% of Hu C/D-IR neurons (pan-neuronal marker) showed the presence of AQP1. The vast majority of AQP1-IR trigeminal sensory neurons (approximately 69.6 ± 3.3%, n = 5) were classified as middle in size, 28.6 ± 3.0% of AQP1-IR neurons were small and only 1.8 ± 0.6% of AQP1-positive neurons were large in size. Amongst the population of AQP1-IR trigeminal neurons as many as 58.5 ± 3.9% were immunopositive to SP, 30.7 ± 2.3% showed the presence of CGRP and 10.9 ± 0.2% coexpressed galanin. In trigeminal ganglion, SP-IR as well as CGRP-IR (but not galanin-IR) nerve fibres were found in close neighbourhood of AQP1-IR neurons. It is concluded that AQP1 is present in certain neuronal subsets of the ovine trigeminal ganglion; however, the exact role of this water channel has to be elucidated.     

Localization of Neuropeptide Y-like immunoreactive structures in the brain of the pejerrey,Odontesthes bonariensis (Teleostei,Atheriniformes)

The aim of this study was to determine the distribution of Neuropeptide-Y (NPY) immunoreactive neurons and fibres in the brain and pituitary of Odontesthes bonariensis by immunohistochemical methods. A wide distribution of immunoreactive NPY (ir-NPY) cells and fibres in the forebrain and midbrain was observed. A prominent ir-NPY nucleus was found in the ventral telencephalon and other ir-NPY cells groups were recognized at the dorso-medial telencephalon. The diencephalon showed ir-NPY cells in the Nucleus entopeduncularis, the Nucleus preopticus periventricularis and in the Nucleus lateralis tuberis. Ir-NPY fibres were conspicuous in the preoptic region and the hypothalamus. There were also numerous ir-NPY fibres at the epithalamic level running ventrally to the hypothalamus and the pituitary stalk. At the rhomboencephalic level, the ir-NPY neurons were observed in the Locus coeruleus. Double-labelled immunostaining showed a close association between ir-NPY fibres that reach the adenohypophysis and growth hormone (GH)- and gonadotropin (GtH)-expressing cells. Although our results exhibit some relevant differences when compared to other fish groups, they support the existence of a conserved NPY system in teleosts.     

The distribution of calbindinD‐28k and parvalbumin immunoreactive neurons in the somatosensory area of the pigeon pallium

GABAergic interneurons regulate the degree of glutamatergic excitation and output of projection neurons. In this study, we investigated the distribution of calbindinD‐28k (CB) and parvalbumin (PV) in the somatosensory area of the pigeon pallium using immunohistochemical method. Our results show that anatomical structures of the somatosensory area of the pigeon pallium consisted of several subdivisions including the hyperpallium, intercalated hyperpallium, mesopallium, nidopallium and basorostralis. Neuronal density was significantly higher in the intercalated hyperpallium and basorostralis than that in the other subdivisions. The density of the CB immunoreactive neurons was generally similar in all the subdivisions; however, the density of PV immunoreactive neurons was particularly prominent in the basorostralis compared with that in the other subdivisions. In addition, the mean proportion of PV immunoreactive neurons to total neurons was higher than that in the CB immunoreactive neurons in all the subdivisions. In brief, our present study shows that PV immunoreactive neurons in the somatosensory area of the pigeon pallium were significantly abundant compared with CB immunoreactive neurons. This finding needs more studies regarding CB‐ and PV‐related functions in the somatosensory area of the avian pallium.