Immunohistochemical properties of motoneurons supplying the porcine trapezius muscle

The trapezius muscle (TRAP) belongs to the scapulothoracic group of muscles, which play a crucial role in the integrity and strength of the upper limb, trunk, head, and neck movements and, thus, in maintaining balance. Combined retrograde tracing (using fluorescent tracer Fast Blue, FB) and double-labelling immunohistochemistry were applied to investigate the chemical coding of motoneurons projecting to the porcine TRAP. FB-positive (FB+) motoneurons supplying the cervical (c-TRAP) and thoracic part (th-TRAP) of the right (injected with the tracer) TRAP were located within the IX-th Rexed lamina in the ipsilateral ventral horn of the grey matter of the spinal medulla. Immunohistochemistry revealed that nearly all the neurons were cholinergic in nature [choline acetyltransferase (CHAT)- or vesicular acetylcholine transporter (VACHT)-positive]. Many retrogradelly labelled neurons displayed also immunoreactivity to calcitonin gene-related peptide (CGRP; approximately 68% of FB+ neurons). The smaller number of nerve cells (5%, 3%, 2% or 1%, respectively) stained for nitric oxide synthase (n-NOS), vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY) and substance P (SP). The retrogradely labelled neurons were closely apposed by nerve fibres expressing immunoreactivity to CHAT, VACHT, CGRP, SP, DβH, VIP, n-NOS, NPY, GAL, Leu-Enk and Met-Enk. Taking into account the clinical relevance of TRAP, the present results may be useful in designing further research aimed at the management of various dysfunctions of the muscle.

Xanthohumol, a prenylated flavonoid from hops (Humulus lupulus L.) exerts multidirectional pro-healing properties towards damaged zebrafish hair cells by regulating the innate immune response

Xanthohumol (XN) is a prominent prenylated flavonoid present in the hop plant (Humulus lupulus L.). Despite undoubted pro-healing properties of hop plant, there is still a need for clinical investigations confirming these effects as well as the underlying molecular mechanisms. The present study was designed to (1) establish the role of XN in non-invasive inflammation induced by chemical damage to zebrafish hair cells, (2) clarify if it influences cell injury severity, neutrophil migration, macrophage activation, cell regeneration, and (3) find out whether it modulates the gene expression profile of chosen immune and stress response markers. All experiments were performed on 3 dpf zebrafish larvae. After fertilization the embryos were transferred to appropriate XN solutions (0.1 μM, 0.3 μM and 0.5 μM). The 40 min 10 μM CuSO4 exposure evoked severe damage to posterior lateral line hair cells triggering a robust acute inflammatory response. Four readouts were selected as the indicators of XN role in the process of inflammation: 1) hair cell death, 2) neutrophil migration towards damaged hair cells, 3) macrophage activation and recruitment to damaged hair cells, 4) hair cell regeneration. The assessments involved in vivo confocal microscopy imaging and qPCR based molecular analysis. It was demonstrated that XN (1) influences death pathway of damaged hair cells by redirecting their severe necrotic phenotype into apoptotic one, (2) impacts the immune response via regulating neutrophil migration, macrophage recruitment and activation (3) modulates gene expression of immune system markers and (4) accelerates hair cell regeneration.

The Effect of Simvastatin on the Dynamics of NF-κB-Regulated Neurodegenerative and Neuroprotective Processes in the Acute Phase of Ischemic Stroke

Statins are lipid-lowering drugs that act by inhibiting 3-hydroxy-3-methylglutaryl coenzyme A reductase, a rate-limiting enzyme in cholesterol biosynthesis. Animal studies have shown neuroprotective effects of statins in cerebral stroke. However, the underlying mechanisms are not fully understood. The nuclear factor-kappa B (NF-κB) transcription factor is involved in the regulation of apoptosis in stroke. Different dimers of NF-κB regulate the gene expression of proteins involved in both neurodegeneration and neuroprotection. We aimed to determine whether simvastatin improves stroke outcome via inhibition of the RelA/p65-containing subunit and downregulation of stroke-induced pro-apoptotic genes or via activation of NF-κB dimers containing the c-Rel subunit and upregulation of anti-apoptotic genes during the acute stroke phase. Eighteen-month-old Wistar rats, subjected to permanent MCAO or sham surgery, were administered simvastatin (20 mg/kg b.w.) or saline for 5 days before the procedure. Stroke outcome was determined by measuring cerebral infarct and assessing motor functions. The expression of NF-κB subunits in various cell populations was investigated using immunofluorescence/confocal microscopy. RelA and c-Rel were detected by WB. The NF-κB-DNA binding activity was investigated using EMSA, and expression of Noxa, Puma, Bcl-2, and Bcl-x genes was analyzed by qRT-PCR. Results showed a 50% infarct size reduction and significant motor function improvement in the simvastatin-treated animals which correlated with a decrease in RelA and a transient increase in the c-Rel level in the nucleus, normalization of the NF-κB-DNA binding activity, and downregulation of the NF-κB-regulated genes. Our results provide new insights into the statin-mediated neuroprotective action against stroke based on NF-κB pathway inhibition.

Kisspeptin and GPR54 Receptor Expression in Endometrial Cancer Tissue

Kisspeptin (KISS) is a natural peptide-discovered in 1996 as a factor inhibiting the ability to metastasize in malignant melanoma. This protein plays also a regulatory role in the process of puberty, the menstrual cycle, spermatogenesis, implantation and development of the human placenta. The present study aimed to evaluate the expression of KISS and its receptor GPR54 in endometrial cancer (EC) tissue, depending on the histological type of cancer, its stage, various demographic characteristics, and clinical conditions in 214 hysterectomy patients. Expression of KISS and GPR54 was confirmed in 99.5% and 100% of the cases, respectively. Hormone replacement therapy and the coexistence of the anti-Müllerian type 2 receptor in cancer tissue enhanced KISS expression. Smoking, on the other hand, decreased KISS expression. GPR54 expression increased with the advancement of the disease (according to FIGO classification). Also, the presence of the anti-Müllerian type 2 receptor in EC increased the level of GPR54. Hypertension, age and miscarriage harmed the presence of GPR54. The histological type of cancer, diabetes type 2, body mass index, hormonal contraception, number of deliveries, birth weight of newborns, breastfeeding time, and the presence of AMH in EC tissue were not associated with the expression of either KISS nor GPR54. The KISS level was also significantly related to the GPR54 level. Considering that KISS is a non-toxic peptide with antimetastatic properties, further investigation is essential to determine the clinical significance of this peptide.

Morphology and immunohistochemical characteristics of the otic ganglion in the chinchilla (Chinchilla laniger Molina)

INTRODUCTION

The available literature provides relatively little information on the morphology of the autonomic head ganglia in rodents including their neurochemical codding.

MATERIAL AND METHODS

Morphological investigations of the otic ganglion of the chinchilla were performed using the modified acetylcholinesterase method. The cellular structure was investigated with histological techniques and neurochemical properties were studied with the double-labelling immunofluorescence method.

RESULTS

Macromorphological investigations allowed the otic ganglion to be identified as a compact, oval agglomeration of neurons and nerve fibers. Multidimensional cross-sections revealed densely arranged neuronal perikarya and two populations of nerve cells differing in size were distinguished. The large cells (40-50 µm) accounted for about 80% of the neurons in the cross-sections. Moreover, a small number of intraganglionic nerve fibers was observed. Immunohistochemical staining revealed that over 85% of the neuronal cell bodies in the otic ganglion contained immunoreactivity to VAChT or ChAT. VIP-immunoreactive perikarya comprised approximately 10% of the ganglionic cells. Double staining revealed the presence of VAChT+ and NOS+ neurons which amounted to about 45% of the nerve cells in the otic ganglion. NOS+ only perikarya comprised approx. 15% of all the neurons. Immunoreactivity to enkephalins, substance P, somatostatin, and galanin was expressed in single nerve cell bodies and nerve fibers except numerous substance P+ intraganglionic nerve fibers. Some of them were stained also for CGRP. Single neurons stained for tyroxine hydroxylase.

CONCLUSIONS

Our results, compared with findings in other rodent species suggest the existence of interspecies differences in the morphology, cellular structure, and immunohistochemical properties of the head autonomic ganglia in mammals.

Dispersal and immunohistochemical characteristics of neurons in the stem of the porcine vagus nerve

The present study investigated the distribution and chemical properties of nerve cell bodies within the trunk of the vagus nerve in juvenile female pigs (n=4) using double-labelling immunofluorescence. The neurons appeared mostly as single cells or formed streaks of cells or small ganglia. Many of the perikarya were cholinergic (VAChT-positive; VAChT+) or adrenergic (DβH+) in nature and no SP+ or CGRP+ neurons were encountered. There were no distinct left-right differences regarding the number and chemical coding of the neuronal somata, however, these characteristics significantly varied between particular nerve segments investigated. The vagosympathetic trunks, and thoracic and abdominal segments of the vagus nerve contained on average (the numerical values represent the means for both the left and right corresponding nerve segments) 142, 236, and 111 PGP 9.5-positive neurons, respectively. Proportions of cholinergic and adrenergic neurons were as follows: 0% and 100%, 54.2% and 33.2%, and 52.8% and 35.4%, respectively. Relatively many neurons in the thoracic and abdominal segments stained also for NOS (39.2% and 39.9%, respectively). It remains to be determined whether the porcine intravagal neurons represent a developmental relic, or whether they have any specific functional significance.

Immunohistochemical characterization of nerve elements in porcine intrinsic laryngeal ganglia

The present study investigated the chemical coding of neurons and nerve fibres in local laryngeal ganglia in pigs (n=5) using double-labelling immunohistochemistry. Virtually all the neurons were cholinergic in nature (ChAT- or VAChT-positive). Only very solitary, small nerve cells (presumably representing interneurons) stained intensely for adrenergic marker, DβH. Many neurons also contained immunoreactivity for NOS (91%), VIP (62.7%), NPY (24.7%), galanin (10%), SP (1.3%) and CGRP (5.3%). No neurons expressing somatostatin or Leu-enkephalin were observed. Nearly all the neuronal somata were densely supplied with varicose cholinergic nerve terminals, which presumably represented preganglionic axons, and some of them were also closely apposed with CGRP- and/or SP-positive varicose nerve endings, which were putative collaterals of extrinsic primary sensory fibres. In conclusion, this study has revealed that intrinsic neurons in the porcine larynx, like in many other mammalian species studied, should be classified as parasympathetic cholinergic neurons expressing biologically active substances, predominantly NOS and VIP. Furthermore, they are likely to receive inputs from not only preganglionic neurons but also primary sensory nerve cells. Finally, it appears that the information on the occurrence of the local laryngeal ganglia should be regularly included in textbooks dealing with the cranial portion of the parasympathetic nervous system in mammals.

The influence of castration on intramural neurons of the urinary bladder trigone in male pigs

The present study investigated the influence of castration performed at neonatal age on neuronal elements in the intramural ganglia of the urinary bladder trigone (UBT) in male pigs using double-labeling immunohistochemistry. The ganglia were examined in intact (IP) 7-day-old (castration day) pigs, and at 3 and 6 months after surgery. In IP and control (3- and 6-month-old noncastrated pigs) groups, virtually, all neurons were adrenergic (68%) or cholinergic (32%) in nature. Many of them (32%, 51%, and 81%, respectively; 56%, 75%, and 85% adrenergic; and 32%, 52%, and 65% cholinergic, respectively) stained for the androgen receptor (AR), and only a small number of nerve cells were caspase-3 (CASP-3)-positive. In 3- and 6-month-old castrated pigs, an excessive loss (87.6% and 87.5%, respectively) of neurons and intraganglionic nerve fibers was observed. The majority of the surviving adrenergic (61% and 72%, respectively) and many cholinergic (41% and 31%, respectively) neurons expressed CASP-3 and were also AR-positive (61% and 66%, and 40% and 36%, respectively). This study revealed for the first time the excessive loss of intramural UBT neurons following castration, which could have resulted from apoptosis induced by androgen deprivation.

The Effect of Castration on Peripheral Autonomic Neurons Supplying Mammalian Male Genitourinary System

This review paper deals with the influence of androgens (testosterone) on pelvic autonomic pathways in male mammals. The vast majority of the relevant information has been gained in experiments involving castration (testosterone deprivation) performed in male rats, and recently, in male pigs. In both species, testosterone significantly affects the biology of the pathway components, including the pelvic neurons. However, there are great differences between rats and pigs in this respect. The most significant alteration is that testosterone deprivation accomplished a few days after birth results some months later in the excessive loss (approximately 90%) of pelvic and urinary bladder trigone intramural neurons in the male pig, while no changes in the number of pelvic neurons are observed in male rats (rats do not have the intramural ganglia). In the castrated pigs, much greater numbers of pelvic neurons than in the non-castrated animals express CGRP, GAL, VIP (peptides known to have neuroprotective properties), and caspase 3, suggesting that neurons die due to apoptosis triggered by androgen deprivation. In contrast, only some morpho-electrophysiological changes affecting neurons following castration are found in male rats. Certain clinicopathological consequences of testosterone deprivation for the functioning of urogenital organs are also discussed.

Inferior vagal ganglion galaninergic response to gastric ulcers

Galanin is a neuropeptide widely expressed in central and peripheral nerves and is known to be engaged in neuronal responses to pathological changes. Stomach ulcerations are one of the most common gastrointestinal disorders. Impaired stomach function in peptic ulcer disease suggests changes in autonomic nerve reflexes controlled by the inferior vagal ganglion, resulting in stomach dysfunction. In this paper, changes in the galaninergic response of inferior vagal neurons to gastric ulceration in a pig model of the disease were analyzed based on the authors' previous studies. The study was performed on 24 animals (12 control and 12 experimental). Gastric ulcers were induced by submucosal injections of 40% acetic acid solution into stomach submucosa and bilateral inferior vagal ganglia were collected one week afterwards. The number of galanin-immunoreactive perikarya in each ganglion was counted to determine fold-changes between both groups of animals and Q-PCR was applied to verify the changes in relative expression level of mRNA encoding both galanin and its receptor subtypes: GalR1, GalR2, GalR3. The results revealed a 2.72-fold increase in the number of galanin-immunoreactive perikarya compared with the controls. Q-PCR revealed that all studied genes were expressed in examined ganglia in both groups of animals. Statistical analysis revealed a 4.63-fold increase in galanin and a 1.45-fold increase in GalR3 mRNA as compared with the controls. No differences were observed between the groups for GalR1 or GalR2. The current study confirmed changes in the galaninergic inferior vagal ganglion response to stomach ulcerations and demonstrated, for the first time, the expression of mRNA encoding all galanin receptor subtypes in the porcine inferior vagal ganglia.

Distribution and chemical coding of phoenixin-immunoreactive nerve structures in the spinal cord of the pig

Phoenixin (PNX) is a newly described peptide found in both neural and non-neural tissues. Until now, no attempts have been made to investigate the expression of PNX in the nervous system of animals other than laboratory rodents, in which an enzyme immunoassay revealed the highest quantity of the substance in the spinal cord. Since the domestic pig, due to its anatomical and histological resemblance to humans, is often used as an animal model in biomedical investigations, the present study was designed to examine PNX-immunoreactivity in the spinal cords of female pigs (n=5). The spinal cords were dissected and divided into the cervical, thoracic, lumbar, sacral and coccygeal segments, which were sectioned transversally into 10-μm-thick serial sections. The sections from each spinal cord segment were processed for double-labelling immunohistochemistry using antibodies against PNX in a mixture with those against calcitonin gene-related peptide (CGRP), substance P (SP) or choline acetyltransferase (CHAT). The PNX-immunoreactivity had a similar distribution in the grey matter of all the spinal cord sections examined and was mainly observed in varicose nerve fibres (NF) that formed a dense plexus in laminae I and II of the dorsal horn. Nearly all of the PNX-immunoreactive NF stained also for CGRP or SP and, interestingly, many of them were CHAT-positive. The present study has provided for the first time the detailed information on the arrangement and chemical features of nerve structures expressing PNX-immunoreactivity in the spinal cord of a large mammal. The exact function of PNX in the spinal cord is not known yet. However, the distribution pattern and immunohistochemical characteristics of PNX-IR NF clearly suggest that this peptite most likely plays a role in spinal noxious signalling.

Nerve structures of the heart and their immunohistochemical characterization in 10-week-old porcine foetuses

The aim of the present study was to investigate the distribution of neuronal perikarya and nerve fibres and their chemical coding in the heart of 10-week-old porcine foetuses. The foetuses, obtained from a local slaughterhouse, were fixed by immersion in 4% buffered (pH 7.4) paraformaldehyde. Cryostat sections of the hearts were processed for single- or double-labelling immunofluorescence methods using antibodies against protein gene product (PGP) dopamine beta-hydroxylase (DβH), acetylcholine vesicular transporter (VAChT) and calcitonin gene-related peptide (CGRP). Numerous clusters of the PGP-positive nerve cells were observed throughout the heart wall. The majority of the clusters were found beneath the epicardium around the root of the aorta, pulmonary trunk and main veins. Some single PGP-positive neurons or small clusters of nerve cells were observed in the epicardium of heart atria and ventricles. The richest network of PGP-positive nerve fibres was observed in the base of the heart near the main cardiac blood vessel openings. Many bundles of PGP-positive nerve fibres were observed throughout the four cardiac chambers. Double-immunohistochemical staining revealed that the majority of the neurons contained immunoreactivity to VAChT, some of them stained for CGRP and the single neuronal somata were DβH-positive. The nerve fibres supplying the heart expressed immunoreactivity to DβH, VAChT or CGRP. The distribution and neurochemical coding of the nerve structures in ten-week-old foetuses are different from those observed in the hearts of juvenile pigs.

Distribution and chemical coding of urinary bladder apex-projecting neurons in aorticorenal and testicular ganglia of the male pig

Combined retrograde tracing and double-labelling immunofluorescence were used to investigate the distribution and chemical coding of neurons in aorticoerenal (ARG) and testicular (TG) ganglia supplying the urinary bladder apex (UBA) in the juvenile male pig (n=4, 12 kg. body weight). Retrograde fluorescent tracer Fast Blue (FB) was injected into the wall of the bladder apex under pentobarbital anesthesia. After three weeks all the pigs were deeply anesthetized and transcardially perfused with 4% buffered paraformaldehyde. TG and ARG were collected and processed for double-labelling immunofluorescence. The presence of tyrosine hydroxylase (TH) or dopamine beta-hydroxylase (DBH), neuropeptide Y (NPY), somatostatin (SOM), galanin (GAL), nitric oxide synthase (NOS) and vesicular acetylcholine transporter (VAChT) were investigated. The cryostat sections were examined with a Zeiss LSM 710 confocal microscope equipped with adequate filter blocks. The TG and ARG were found to contain many FB-positive neurons projecting to the UBA (UBA-PN). The UBA-PN were distributed in both TG and ARG. The majority were found in the left ganglia, mostly in TG. Immunohistochemistry disclosed that the vast majority of UBA-PN were noradrenergic (TH- and/or DBH-positive). Many noradrenergic neurons also contained immunoreactivity to NPY, SOM or GAL. Most of the UBA-PN were supplied with varicose VAChT-, or NOS- IR (immunoreactive) nerve fibres. This study has revealed a relatively large population of differently coded ARG and TG neurons projecting to the porcine urinary bladder. As judged from their neurochemical organization these nerve cells constitute an important element of the complex neuro-endocrine system involved in the regulation of the porcine urogenital organ function.

Innervation of internal female genital organs in the pig during prenatal development

This study investigated the innervation of internal genital organs in 5-, 7- and 10-week-old female pig foetuses using single and double-labelling immunofluorescence methods. The structure and topography of the organs was examined using a scanning electron microscope (SEM). The investigations revealed differences in the innervation between the three developmental periods. Immunostaining for protein gene product 9.5 (PGP; general neural marker) disclosed solitary nerve fibres in the external part of the gonadal ridge and just outside of the mesenchyme surrounding mesonephric ducts in 5-week-old foetuses. Double-labelling immunohistochemistry revealed that nerve fibres associated with the ridge expressed dopamine β-hydroxylase (DβH; adrenergic marker) or vesicular acetylcholine transporter (VAChT; cholinergic marker). In 7-week-old foetuses, the PGP-positive nerve terminals were absent from the gonad but some of them ran outside and along, and sometimes penetrated into the mesenchyme surrounding the tubal and uterine segments of the paramesonephric ducts and uterovaginal canal. Few axons penetrated into the mesenchyme. DβH-positive fibres were found in single nerve strands or bundles distributed at the edge of the mesenchyme. VAChT-positive nerve terminals formed delicate bundles located at the edge of the mesenchyme, and the single nerves penetrated into the mesenchyme. DβH was also expressed by neurons which formed cell clusters comprising also DβH- or VAChT-positive nerve fibres. In 10-week-old foetuses, PGP-positive nerve fibres were still absent from the ovary but some were distributed in the mesenchyme associated with the uterovaginal canal and uterine and a tubal segment of the paramesonephric ducts, respectively. DβH- or VAChT-positive nerve fibres were distributed at the periphery of the mesenchyme associated with the uterovaginal canal. Some DβH- and many VAChT-positive nerve fibres were evenly distributed throughout the mesenchyme. The clusters of nerve cells comprised DβH-positive perikarya and DβH- or VAChT-positive nerve fibres. The investigations revealed no DβH/VAChT-positive nerve fibres or neurons as well as no nerve structures stained for calcitonin gene-related peptide and/or substance P (sensory markers) associated with the genital organs in the studied prenatal periods.

The expression of androgen receptor in neurons of the anterior pelvic ganglion and celiac-superior mesenteric ganglion in the male pig

The present study investigated the expression of androgen receptor (AR) in neurons of the anterior pelvic ganglion (APG) and celiac-superior mesenteric ganglion (CSMG; ganglion not involved in the innervation of reproductive organs) in the male pig with quantitative real-time PCR (qPCR) and immunohistochemistry. qPCR investigations revealed that the level of AR gene expression in the APG tissue was approximately 2.5 times higher in the adult (180-day-old) than in the juvenile (7-day-old) boars. Furthermore, in both the adult and juvenile animals it was sig- nificantly higher in the APG than in CSMG tissue (42 and 85 times higher, respectively). Immu- nofluorescence results fully confirmed those obtained with qPCR. In the adult boars, nearly all adrenergic (DβH-positive) and the majority of non-adrenergic neurons in APG stained for AR. In the juvenile animals, about half of the adrenergic and non-adrenergic neurons were AR-posi- tive. In both the adult and juvenile animals, only solitary CSMG neurons stained for AR. The present results suggest that in the male pig, pelvic neurons should be considered as an element of highly testosterone-dependent autonomic circuits involved in the regulation of urogenital func- tion, and that their sensitization to androgens is a dynamic process, increasing during the prepu- bertal period.

Galaninergic intramural nerve and tissue reaction to antral ulcerations

BACKGROUND

Well-developed galaninergic gastric intramural nerve system is known to regulate multiple stomach functions in physiological and pathological conditions. Stomach ulcer, a disorder commonly occurring in humans and animals, is accompanied by inflammatory reaction. Inflammation can cause intramural neurons to change their neurochemical profile. Galanin and its receptors are involved in inflammation of many organs, however, their direct participation in stomach reaction to ulcer is not known. Therefore, the aim of the study was to investigate adaptive changes in the chemical coding of galaninergic intramural neurons and mRNA expression encoding Gal, GalR1, GalR2, GalR3 receptors in the region of the porcine stomach directly adjacent to the ulcer location.

METHODS

The experiment was performed on 24 pigs, divided into control and experimental groups. In 12 experimental animals, stomach antrum ulcers were experimentally induced by submucosal injection of acetic acid solution. Stomach wall directly adjacent to the ulcer was examined by: (1) double immunohistochemistry-to verify the changes in the number of galaninergic neurons (submucosal, myenteric) and fibers; (2) real-time PCR to verify changes in mRNA expression encoding galanin, GalR1, GalR2, GalR3 receptors.

KEY RESULTS

In the experimental animals, the number of Gal-immunoreactive submucosal perikarya was increased, while the number of galaninergic myenteric neurons and fibers (in all the stomach wall layers) remained unchanged. The expression of mRNA encoding all galanin receptors was increased.

CONCLUSIONS & INTERFERENCES

The results obtained unveiled the participation of galanin and galanin receptors in the stomach tissue response to antral ulcerations.

Pituitary adenylate cyclase-activating polypeptide (PACAP-38) plays an inhibitory role against inflammation induced by chemical damage to zebrafish hair cells

Pituitary adenylate cyclase-activating polypeptide (PACAP-38) is a common neuropeptide exerting a wide spectrum of functions in many fields, including immunology. In the present study, 5-day post-fertilization (dpf) zebrafish larvae of three diverse genetic lines [transgenic lines Tg(MPX:GFP) with GFP-labelled neutrophils and Tg(pou4f3:GAP-GFP) with GFP-labelled hair cells and the wild-type Tuebingen] were used to investigate an inhibitory role of PACAP-38 in inflammation associated with damaged hair cells of the lateral line. Individuals of each genetic line were assigned to four groups: (1) control, and those consisting of larvae exposed to (2) 10 µM CuSO4, (3) 10 µM CuSO4+100 nM PACAP-38 and (4) 100 nM PACAP-38, respectively. Forty-minute exposure to CuSO4 solution was applied to evoke necrosis of hair cells and consequent inflammation. The inhibitory role of PACAP-38 was investigated in vivo under a confocal microscope by counting neutrophils migrating towards damaged hair cells in Tg(MPX:GFP) larvae. In CuSO4-treated individuals, the number of neutrophils associated with hair cells was dramatically increased, while PACAP-38 co-treatment resulted in its over 2-fold decrease. However, co-treatment with PACAP-38 did not prevent hair cells from extensive necrosis, which was found in Tg(pou4f3:GAP-GFP) individuals. Real-Time PCR analysis performed in wild-type larvae demonstrated differential expression pattern of stress and inflammation inducible markers. The most significant findings showed that CuSO4 exposure up-regulated the expression of IL-8, IL-1β, IL-6 and ATF3, while after PACAP-38 co-treatment expression levels of these genes were significantly decreased. The presence of transcripts for all PACAP receptors in neutrophils was also revealed. Adcyap1r1a and vipr1b appeared to be predominant forms. The present results suggest that PACAP-38 should be considered as a factor playing an important regulatory role in inflammatory response associated with pathological processes affecting zebrafish hair cells and it cannot be excluded that this interesting property has more universal significance.

Neuropeptides and lymphocyte populations in the porcine ileum and ileocecal lymph nodes during postnatal life

The maturation-related changes in the concentrations of galanin (Gal), vasoactive intestinal polypeptide (VIP), substance P (SP) and somatostatin (Som), as well as in subpopulations of lymphocytes expressing antigens CD2 (lymphocytes T), CD4 (T helper), CD8 (T cytotoxic), CD21 (B lymphocytes), CD5-/CD8+ (NK cells) and TCRgamma/delta (gut mucosal/intraepitelial cells) were studied in the ileal Peyer's patches and ileo-cecal lymph nodes in female pigs aged 3 days, 2 weeks, 4 weeks and 4 months. As regards neuropeptide concentrations statistically significant changes in the ileum and lymph nodes were found only in case of Gal and VIP. The concentrations of neuropeptides were significantly higher only in new-born animals. As regards the changes in subpopulations of lymphocytes, statistically significant changes were noticed only in 4-months old animals and were dealing only with CD2+ and TCRgamma/delta cells in the ileum as well as CD4+, CD8+, CD21+ and TCRgamma/delta in lymph nodes. The highest number of CD8+, CD21+ and TCRgamma/delta lymphocytes occurred in 4-months old animals.

Efficacy of lateral- versus medial-approach hip joint capsule denervation as surgical treatments of the hip joint pain; a neuronal tract tracing study in the sheep

OBJECTIVE

To evaluate efficacy of denervation of the of the hip joint capsule (HJC), as a treatment of hip joint pain. Specifically, we tested the hypothesis that HJC denervation will significantly reduce the number of sensory neurons innervating the capsule.

STUDY DESIGN

Denervation of the HJC from a medial or lateral approach was followed by retrograde tracing of sensory neurons innervating the capsule.

ANIMALS

Twenty adult male sheep (30-40 kg of body weight; Polish merino breed) were used in the study.

METHODS

The hip joint was denervated from medial (n = 5) or lateral (n = 5) surgical approaches. Immediately after denervation, the retrograde neural tract tracer Fast Blue (FB) was injected into the HJC. An additional ten animals (n = 5 for medial and n = 5 for lateral approach) received the same treatment without HJC denervation to provide the appropriate controls.

RESULTS

Results of the study revealed that the vast majority of retrogradely labelled sensory neurons innervating the HJC originate from fifth lumbar to second sacral dorsal root ganglia. Both the medial and the lateral denervations significantly reduced the number of sensory neurons innervating the HJC (39.2% and 69.0% reduction respectively).

CONCLUSIONS

These results show that denervation of the HJC is an effective surgical procedure for reduction of the sensory neuronal input to the HJC. Moreover, the lateral approach was found to be significantly more effective for reducing sensory innervation as compared to the medial one.

Ghrelin-immunoreactive cells in the gastrointestinal tract of hypertensive rats

INTRODUCTION

Ghrelin, an appetite-stimulating hormone secreted by the endocrine cells of the gastrointestinal (GI) tract, has recently been shown to affect the function of the cardiovascular system. This study aimed to assess the number and morphology of ghrelin-immunopositive (GhrIP) cells in the gastrointestinal tract of rats at different developmental phases of experimentally evoked renovascular hypertension.

MATERIAL AND METHODS

The study involved 40 rats divided into two groups: control (C; n = 20) and rats with experimentally induced hypertension (EH; n = 20). The Goldblatt model of two-kidneys, one clip (2K1C) was used to induce hypertension. Renovascular hypertension was maintained for either 3 (EH1 group; n = 10) or 42 (EH2 group; n = 10) days. Paraffin sections from the cardia, corpus and pylorus of the stomach, as well as from the duodenum, jejunum, ileum and colon were processed for peroxidase immunohistochemistry.

RESULTS

The number of GhrIP cells was significantly higher in the cardia and corpus of the stomach as well as the duodenum and jejunum of hypertensive rats compared to that found in the control animals.

CONCLUSIONS

The increased number of GhrIP cells in the rat gastrointestinal tract after partial unilateral ligation of the renal artery suggests that renovascular hypertension may affect ghrelin secretion, which can contribute to the development of cardiovascular complications.

Protective Effects of Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP) Against Oxidative Stress in Zebrafish Hair Cells

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a pleiotropic neuropeptide, with known antiapoptotic functions. Our previous in vitro study has demonstrated the ameliorative role of PACAP-38 in chicken hair cells under oxidative stress conditions, but its effects on living hair cells is now yet known. Therefore, the aim of the present study was to investigate in vivo the protective role of PACAP-38 in hair cells found in zebrafish (Danio rerio) sense organs-neuromasts. To induce oxidative stress the 5-day postfertilization (dpf) zebrafish larvae were exposed to 1.5 mM H₂O₂ for 15 min or 1 h. This resulted in an increase in caspase-3 and p-38 MAPK level in the hair cells as well as in an impairment of the larvae basic behavior. To investigate the ameliorative role of PACAP-38, the larvae were incubated with a mixture of 1.5 mM H₂O₂ and 100 nM PACAP-38 following 1 h preincubation with 100 nM PACAP-38 only. PACAP-38 abilities to prevent hair cells from apoptosis were investigated. Whole-mount immunohistochemistry and confocal microscopy analyses revealed that PACAP-38 treatment decreased the cleaved caspase-3 level in the hair cells, but had no influence on p-38 MAPK. The analyses of basic locomotor activity supported the protective role of PACAP-38 by demonstrating the improvement of the fish behavior after PACAP-38 treatment. In summary, our in vivo findings demonstrate that PACAP-38 protects zebrafish hair cells from oxidative stress by attenuating oxidative stress-induced apoptosis.

The influence of resiniferatoxin on the chemical coding of caudal mesenteric ganglion neurons supplying the urinary bladder in the pig

Resiniferatoxin (RTX) is used as experimental drug therapy for a range of neurogenic urinary bladder disorders. The present study investigated the chemical coding of caudal mesenteric ganglion (CaMG) neurons supplying the porcine urinary bladder after intravesical RTX instillation. The CaMG neurons were visualized with retrograde tracer Fast Blue (FB) and their chemical profile was disclosed with double-labelling immunohistochemistry using antibodies against tyrosine hydroxylase (TH), neuropeptide Y (NPY), vasoactive intestinal polypeptide (VIP), somatostatin (SOM), calbindin (CB), galanin (GAL) and neuronal nitric oxide synthase (nNOS). It was found that in both the control (n = 6) and RTX-treated pigs (n = 6), the vast majority (92.3 ± 2.7% and 93.1 ± 1.3%, respectively) of FB-positive (FB⁺) nerve cells were TH⁺. Intravesical instillation of RTX caused a decrease in the number of FB⁺ / TH ⁺ neurons immunopositive to NPY (91.0 ± 2.2% in control animals vs. 58.8 ± 5.0% in RTX-treated pigs) or VIP (1.7 ± 0.5% vs. 0%) and an increase in the number of FB⁺ / TH⁺ neurons immunoreactive to SOM (3.4 ± 1.5% vs. 20.6 ± 4.3%), CB (1.8 ±0.7% vs. 13.4 ± 2.3%), GAL (1.5 ± 0.6% vs. 7.5 ± 1.0%) or nNOS (0% vs. 10.9 ± 3.4%). The present results suggest that therapeutic effects of RTX on the mammalian urinary bladder can be partly mediated by CaMG neurons.

Chemical Coding of Sensory Neurons Supplying the Hip Joint Capsule in the Sheep

Immunohistochemical properties of nerve fibres supplying the joint capsule were previously described in many mammalian species, but the localization of sensory neurons supplying this structure was studied only in laboratory animals, the rat and rabbit. However, there is no comprehensive data on the chemical coding of sensory neurons projecting to the hip joint capsule (HJC). The aim of this study was to establish immunohistochemical properties of sensory neurons supplying HJC in the sheep. The study was carried out on 10 sheep, weighing about 30-40 kg. The animals were injected with a retrograde neural tracer Fast Blue (FB) into HJC. Sections of the spinal ganglia (SpG) with FB-positive (FB+) neurons were stained using antibodies against calcitonin gene-related peptide (CGRP) substance P (SP), pituitary adenylate cyclase-activating peptide (PACAP), nitric oxide synthase (n-NOS), neuropeptide Y (NPY), vasoactive intestinal polypeptide (VIP), Leu-5-enkephalin (Leu-Enk), galanin (GAL) and vesicular acetylcholine transporter (VACHT). The vast majority of FB+ neurons supplying HJC was found in the ganglia from the 5th lumbar to the 2nd sacral. Immunohistochemistry revealed that most of these neurons were immunoreactive to CGRP or SP (80.7 ± 8.0% or 56.4 ± 4.8%, respectively) and many of them stained for PACAP or GAL (52.9 ± 2.9% or 50.6 ± 19.7%, respectively). Other populations of FB+ neurons were those immunoreactive to n-NOS (37.8 ± 9.7%), NPY (34.6 ± 6.7%), VIP (28.7 ± 4.8%), Leu-Enk (27.1 ± 14.6) and VACHT (16.7 ± 9.6).

The Influence of Gastric Antral Ulcerations on the Expression of Galanin and GalR1, GalR2, GalR3 Receptors in the Pylorus with Regard to Gastric Intrinsic Innervation of the Pyloric Sphincter

Gastric antrum ulcerations are common disorders occurring in humans and animals. Such localization of ulcers disturbs the gastric emptying process, which is precisely controlled by the pylorus. Galanin (Gal) and its receptors are commonly accepted to participate in the regulation of inflammatory processes and neuronal plasticity. Their role in the regulation of gastrointestinal motility is also widely described. However, there is lack of data considering antral ulcerations in relation to changes in the expression of Gal and GalR1, GalR2, GalR3 receptors in the pyloric wall tissue and galaninergic intramural innervation of the pylorus. Two groups of pigs were used in the study: healthy gilts and gilts with experimentally induced antral ulcers. By double immunocytochemistry percentages of myenteric and submucosal neurons expressing Gal-immunoreactivity were determined in the pyloric wall tissue and in the population of gastric descending neurons supplying the pyloric sphincter (labelled by retrograde Fast Blue neuronal tracer). The percentage of Gal-immunoreactive neurons increased only in the myenteric plexus of the pyloric wall (from 16.14±2.06% in control to 25.5±2.07% in experimental animals), while no significant differences in other neuronal populations were observed between animals of both groups. Real-Time PCR revealed the increased expression of mRNA encoding Gal and GalR1 receptor in the pyloric wall tissue of the experimental animals, while the expression(s) of GalR2 and GalR3 were not significantly changed. The results obtained suggest the involvement of Gal, GalR1 and galaninergic pyloric myenteric neurons in the response of pyloric wall structures to antral ulcerations.

Zebrafish: an animal model for research in veterinary medicine

The zebrafish (Danio rerio) has become known as an excellent model organism for studies of vertebrate biology, vertebrate genetics, embryonal development, diseases and drug screening. Nevertheless, there is still lack of detailed reports about usage of the zebrafish as a model in veterinary medicine. Comparing to other vertebrates, they can lay hundreds of eggs at weekly intervals, externally fertilized zebrafish embryos are accessible to observation and manipulation at all stages of their development, which makes possible to simplify the research techniques such as fate mapping, fluorescent tracer time-lapse lineage analysis and single cell transplantation. Although zebrafish are only 2.5 cm long, they are easy to maintain. Intraperitoneal and intracerebroventricular injections, blood sampling and measurement of food intake are possible to be carry out in adult zebrafish. Danio rerio is a useful animal model for neurobiology, developmental biology, drug research, virology, microbiology and genetics. A lot of diseases, for which the zebrafish is a perfect model organism, affect aquatic animals. For a part of them, like those caused by Mycobacterium marinum or Pseudoloma neutrophila, Danio rerio is a natural host, but the zebrafish is also susceptible to the most of fish diseases including Itch, Spring viraemia of carp and Infectious spleen and kidney necrosis. The zebrafish is commonly used in research of bacterial virulence. The zebrafish embryo allows for rapid, non-invasive and real time analysis of bacterial infections in a vertebrate host. Plenty of common pathogens can be examined using zebrafish model: Streptococcus iniae, Vibrio anguillarum or Listeria monocytogenes. The steps are taken to use the zebrafish also in fungal research, especially that dealing with Candida albicans and Cryptococcus neoformans. Although, the zebrafish is used commonly as an animal model to study diseases caused by external agents, it is also useful in studies of metabolic disorders including fatty liver disease and diabetes. The zebrafish is also a valuable tool as a model in behavioral studies connected with feeding, predator evasion, habituation and memory or lateralized control of behavior. The aim of the present article is to familiarize the reader with the possibilities of Danio rerio as an experimental model for veterinary medicine.

Innervation of the chinchilla testis, epididymis, and vas deferens

The study was performed on six male chinchillas. The animals were anaesthetised with ether and the anaesthesia was deepened with nembuthal injected intraperitoneally. The chinchillas were then transcardially perfused with 0.4 L of 4% buffered paraformaldehyde, and testes, epididymides, and vasa deferentia were collected. The tunica albuginea from one testis from each chinchilla was stained as whole-mount preparation. The tissues were cut into 12 μm-thick cryostat sections, and processed for double-immunofluorescence method. In all organs studied, the most abundant nerve fibres were dopamine β hydroxylase positive (DβH+). Some of them contained neuropeptide Y (NPY). Sporadically NPY-positive-only nerve fibres were found. Single DβH+ nerve terminals contained also galanine. Small numbers of the nerve fibres supplying studied organs were stained for substance P (SP) and calitonin gene related peptide (CGRP). Almost all SP+ fibres were also CGRP+, whereas single CGRP+ nerves were SPimmunonegative. Some nerve terminals were immunoreactive to vesicular acetylcholine transporter and vasoactive intestinal peptide. The organs studied were innervated unevenly. The highest density of the nerves was found in the areas of the tunica albuginea adjacent to the mesorchial border of the testis and their number gradually decreased towards the free border of the gonad. None of the vascular tissue of the testicular parenchyma was free of the nerve fibres, except sporadically encountered DβH+ nerves which supply seminiferous tubules. Within the head of the epididymis a moderate number of nerve terminals were found, but in the body and tail of the organ the number of nerves gradually increased. The vas deferens was supplied with very numerous nerve fibres. There were no differences in the density of the innervation between the funicular and abdominal part of the vas deferens.

Caudal mesenteric ganglion in the sheep - macroanatomical and immunohistochemical study

The caudal mesenteric ganglion (CaMG) is a prevetrebral ganglion which provides innervation to a number of organs in the abdominal and pelvic cavity. The morphology of CaMG and the chemical coding of neurones in this ganglion have been described in humans and many animal species, but data on this topic in the sheep are entirely lacking. This prompted us to undertake a study to determine the localization and morphology of sheep CaMG as well as immunohistochemical properties of its neurons. The study was carried out on 8 adult sheep, weighing from 40 to 60 kg each. The sheep were deeply anaesthetised and transcardially perfused with 4% paraformaldehyde. CaMG-s were exposed and their location was determined. Macroanatomical observations have revealed that the ovine CaMG is located at the level of last two lumbar (L5 or L6) and the first sacral (S1) vertebrae. The ganglion represents an unpaired structure composed of several, sequentially arranged aggregates of neurons. Immunohistochemical investigations revealed that nearly all (99.5%) the neurons were DβH-IR and were richly supplied by VACHT-IR nerve terminals forming "basket-like" structures around the perikarya. VACHT-IR neurones were not determined. Many neurons (55%) contained immunoreactivity to NPY, some of them (10%) stained for Met-ENK and solitary nerve cells were GAL-positive. CGRP-IR nerve fibres were numerous and a large number of them simultaneously expressed immunoreactivity to SP. Single, weakly stained neurones were SP-IR and only very few nerve cells weakly stained for VIP.

Sources of sensory innervation of the hip joint capsule in the rabbit - a retrograde tracing study

The aim of the study was to investigate the sensory innervation of the hip joint capsule in the rabbit. Individual animals were injected with retrograde fluorescent tracer Fast Blue (FB) into the lateral aspect of the left hip joint capsule (group LAT, n = 5) or into the medial aspect of the hip joint capsule (group MED, n = 5), respectively. FB-positive (FB+) neurons were found within ipsilateral lumbar (L) and sacral (S) dorsal root ganglia (DRG) from L7 to S2 (group LAT) and from L6 to S4 (group MED). They were round or oval in shape with a diameter of 20-90 μm. The neurons were evenly distributed throughout the ganglia. The average number of FB+ neurons was 16 ± 2.8 and 27.6 ± 3.5 in rabbits from LAT and MED, respectively. The largest average number of FB+ neurons in animals of group LAT was found within the S1 DRG (8 ± 1.7), while S2 ganglion contained the smallest number of the neurons (3.6 ± 1). In the L7 DRG, the average number of FB+ neurons was 6.2 ± 1.6. In rabbits of MED group, the largest number of FB+ neurons was found within the S1 DRG (13.4 ± 4), while the smallest one was found within the S3 ganglion (1.4 ± 0.4). In L6, L7, S2 and S4 ganglia, the number of retrogradely labelled neurons amounted to 1.6 ± 0.5, 4 ± 1.5, 4.4 ± 1.5 and 2.8 ± 1.7, respectively. The data obtained can be very useful for further investigations regarding the efficacy of denervation in the therapy of hip joint disorders in rabbits.

The influence of ileitis on the neurochemistry of the caudal mesenteric ganglion in the pig

BACKGROUND

Some literature data suggest that there is a regulatory neuronal circuit between the small and the large bowel. To verify this hypothesis the present study investigated: (i) the distribution, chemical coding and routing of caudal mesenteric ganglion (CaMG) neurons participating in an intestinointestinal reflex pathway involving ileal descending neurons and viscerofugal colonic neurons and (ii) possible changes in the neuroarchitecture of this pathway evoked by chemically induced ileitis in juvenile pigs (n=16).

METHODS

Combined retrograde tract tracing and transections of the intermesenteric or caudal colonic nerves were applied. In addition, double immunostainings was used to investigate the chemical coding of retrogradely labeled CaMG neurons and intraganglionic nerve terminals apposed to them, under normal and inflammatory conditions.

KEY RESULTS

The majority of the ileum-projecting neurons were found in the caudal part of CaMG. Disruption of particular nerve pathways resulted in diminished number of retrogradely labeled neurons, ipsilateral to the side of manipulation. In normal pigs, ileum-projecting CaMG neurons stained for tyrosine hydroxylase, dopamine-β-hydroxylase, neuropeptide Y (NPY), somatostatin and galanin (GAL). The number and chemical coding of the neurons in the inflamed animals were similar to those observed in the normal pigs. However, in the inflamed pigs, the number of NPY-, GAL- or substance P-positive nerve terminals supplying retrogradely labeled neurons was increased.

CONCLUSIONS & INFERENCES

The present results suggest that inflammatory processes of the porcine ileum are able to induce changes in the intraganglionic architecture of a sympathetic ganglion located at discrete distance from the affected bowel segment.

Distribution and nerve pathways of neurons supplying the bulbourethral gland in the pig

The present study has disclosed for the first time the distribution and peripheral nerve pathways of autonomic and primary afferent neurons projecting to the bulbourethral gland (BG) in a mammalian species, the pig (n = 5), using combined retrograde tracing and cutting the hypogastric (n = 3) or pelvic (n = 3) nerve. Neurons projecting to the right BG were found in pelvic ganglia (PG), sympathetic chain ganglia (SChG; L2-S3), the caudal mesenteric ganglion (CaMG) and dorsal root ganglia (DRG; L1-L3, S1-S3). In general, the majority (about 75%) of them were located in the ipsilateral ganglia. Results of denervation experiments suggest that the neurons located in CaMG, and lumbar SChG and DRG project through the hypogastric nerve while processes of those found in the sacral SChG and DRG travel through the pelvic nerve or pelvic branch of the pudendal nerve. Moreover, the results obtained also suggest that the 'crossing points' (i.e. the areas where nerve fibres reach the opposite side) for the neurons found in the contralateral CaMG are located partly at the level of this ganglion and, for a smaller number of the nerve cells, at the level of the pelvic plexus. The crossing points for the SChG and DRG neurons are probably situated at the level of sympathetic chains and, for sacral SChG neurons, at the level of the pelvic plexus. The diversity of sources of the nerve supply to the porcine BG corresponds well with the variety (as previously distinguished with immunohistochemistry) of its intrinsic nerve fibre populations.

The distribution and chemical coding of intramural neurons supplying the porcine stomach - the study on normal pigs and on animals suffering from swine dysentery

The present study was designed to investigate the expression of biologically active substances by intramural neurons supplying the stomach in normal (control) pigs and in pigs suffering from dysentery. Eight juvenile female pigs were used. Both dysenteric (n = 4; inoculated with Brachyspira hyodysenteriae) and control (n = 4) animals were deeply anaesthetized, transcardially perfused with buffered paraformalehyde, and tissue samples comprising all layers of the wall of the ventricular fundus were collected. 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 chemical coding using antibodies against vesicular acetylcholine (ACh) transporter (VAChT), nitric oxide synthase (NOS), galanin (GAL), vasoactive intestinal polypeptide (VIP), somatostatin (SOM), Leu(5)-enkephalin (LENK), substance P (SP) and calcitonin gene-related peptide (CGRP). In both inner and outer submucosal plexuses of the control pigs, the majority of neurons were SP (55% and 58%, respectively)- or VAChT (54%)-positive. Many neurons stained also for CGRP (43 and 45%) or GAL (20% and 18%) and solitary perikarya were NOS-, SOM- or VIP-positive. The myenteric plexus neurons stained for NOS (20%), VAChT (15%), GAL (10%), VIP (7%), SP (6%) or CGRP (solitary neurons), but they were SOM-negative. No intramural neurons immunoreactive to LENK were found. The most remarkable difference in the chemical coding of enteric neurons between the control and dysenteric pigs was a very increased number of GAL- and VAChT-positive nerve cells (up to 61% and 85%, respectively) in submucosal plexuses of the infected animals. The present results suggest that GAL and ACh have a specific role in local neural circuits of the inflamed porcine stomach in the course of swine dysentery.

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 influence of experimental ileitis on the neuropeptide coding of enteric neurons in the pig

In the present study, both the ELISA test and immunohistochemical staining were used to investigate the influence of artificially induced ileitis on the chemical coding of enteric neurons in the pig. The ileum wall in experimental (E) pigs was injected in multiple sites with 4% paraformaldehyde to induce inflammation, while in the control (C) animals, the organ was injected with 0.1M phosphate buffer (pH 7.4). Three days after ileitis induction, samples of ileum wall from all the animals were evaluated for VIP, SP, CGRP, NPY, GAL and SOM concentration (ELISA test) and the expression of these biologically active substances by the enteric neurons (immunohistochemical staining). Quantitative results showed that ileitis decreased tissue concentration of VIP, CGRP and SOM but increased tissue concentration of SP, NPY and GAL. Immunochemistry revealed that in both the experimental and control pigs, VIP-positive (VIP+) nerve fibers supplied mainly ileal blood vessels, and the labeled pericarya were located in the inner (ISP) and outer submucous plexus (OSP). SP+ and CGRP+ nerve terminals were found in both the mucous and muscular membrane, while the labeled pericarya were found in ISP, OSP and myenteric plexus (MP). In both C and E pigs, the very few nerve terminals containing NPY and SOM were located mainly in the mucous membrane. NPY- or/and SOM-immunopositive nerve cell bodies were found in ISP, OSP and MP. GAL+ nerve fibers supplied all layers of the ileum and were most numerous in the muscular membrane, while the labeled pericarya were present in all the enteric plexuses. The present results suggest that enteric neurons are highly plastic in their response to inflammation.

Adrenergic, nitrergic and peptidergic innervation of the urethral muscle in the boar

In this study, the innervation of the urethral muscle in adult male pigs was investigated using combined NADPH-diaphorase (NADPH-d) histochemistry and immunocytochemistry. Nerve fibres supplying the urethral muscle were found to show NADPH-d activity and they also expressed immunoreactivity to catecholamine synthesising enzymes including tyrosine hydoxylase (TH) and dopamine-beta-hydroxylase (DbetaH) as well as to: vasoactive intestinal polypeptide (VIP) and neuropeptide Y (NPY). Different subpopulations of the nerve fibres (NADPH-d positive, TH-, DbetaH-, VIP- and NPY-immunoreactive (IR), but also NADPH-d/VIP- and NADPH-d/NPY-IR) were disclosed. These nerve fibres were observed not only to run among muscle fibres of the urethral muscle, but also within extrinsic nerve trunks. Moreover, in the organ studied, numerous ganglia were found. The intramural ganglia, composed of a few to 30 neurons were located in the proximal, middle and distal regions of the pelvic urethra. In the vicinity of the urethral muscle, there were mainly small ganglia containing two to several neurons, but also larger ganglia consisting of up to tens neurons were encountered in the connective tissue surrounding the pelvic urethra. In the ganglia observed in the neighbourhood of the urethral muscle, different subpopulations of nerve cells were found, namely: catecholaminergic, nitrergic, VIP-IR, NPY-IR and also NADPH-d/DbetaH-, NADPH-d/VIP- and NADPH-d/NPY-positive. Possible sources of the innervation for this muscle were also discussed.

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.

Immunohistochemical characterisation of cholinergic neurons in the anterior pelvic ganglion of the male pig

This study investigated immunohistochemical properties of cholinergic neurons in the anterior pelvic ganglion (APG) of juvenile male pigs (n=7). Cholinergic neurons were identified using antibodies against choline acetyltransferase (ChAT) and vesicular acetylcholine transporter (VAChT). Immunoblotting was applied to verify the specificity of ChAT-immunostaining. Western blotting performed on APG tissue homogenates detected single immunoreactive protein with a molecular weight matching that of ChAT (71.6 kDa). It was found that many APG neurons expressed immunoreactivity to ChAT or VAChT (40% and 39% of the neurons, respectively). The analysis of adjacent sections from the ganglion revealed complete colocalization of ChAT and VAChT in these nerve cells. Furthermore, virtually all the ChAT-positive neurons were tyrosine hydroxylase (TH)-negative (non-adrenergic) but many of them displayed immunoreactivity to nitric oxide synthase (NOS), vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY) or somatostatin (SOM). There were also single nerve cell bodies that stained for neither ChAT nor TH. The comparison of the adjacent sections revealed that NOS, VIP, NPY and SOM were simultaneously co-expressed in the majority of the cholinergic somata. ChAT- or VAChT-positive varicose nerve terminals supplied nearly all neuronal profiles within the ganglion often forming loose basket-like formations surrounding the particular nerve cell bodies. The present study for the first time has revealed that nearly all non-adrenergic neurons in the porcine APG are cholinergic in nature, i.e. express immunoreactivity for ChAT and VAChT. Considering a high coincidence between the chemical coding of non-adrenergic (cholinergic) nerve fibres supplying some porcine male reproductive organs described in earlier papers and that of cholinergic pelvic neurons found in this study it is further concluded that pelvic ganglia are probably the major source of cholinergic innervation for the porcine urogenital system.

Immunohistochemical study of the otic ganglion in the pig

The presence of choline acetyltransferase (ChAT), vesicular acetylcholine transporter (VAChT), neuropeptide Y (NPY), vasoactive intestinal polypeptide (VIP), somatostatin (SOM), galanin (GAL), substance P (SP) and calcitonin gene-related peptide (CGRP) was studied in neurons and nerve fibers of the porcine otic ganglion. ChAT-positive neurons were very numerous while VAChT-positive nerve cells were moderate in number. The number of neurons containing NPY and VIP was lower and those containing SOM, GAL, SP or CGRP were observed as scarce, or single nerve cells. The above mentioned substances (except SOM) were present in nerve fibers of the ganglion. ChAT- and VAChT-positive nerve fibers were numerous, while the number of nerve terminals containing NPY, VIP and SP was lower. GAL- and CGRP-positive nerve fibers were scarce.

Differences in the chemical coding of nerve fibres supplying major populations of neurons between the caudal mesenteric ganglion and anterior pelvic ganglion in the male pig

The present study was designed to investigate and to compare the chemical coding of nerve fibres supplying major populations of neurons in the caudal mesenteric (CaMG) and anterior pelvic (APG) ganglion in juvenile male pigs (n=5) using double-labelling immunofluorescence. The co-existence patterns of some biologically active substances including tyrosine hydroxylase (TH) and vesicular acetylcholine transporter (VAChT) as well as vasoactive intestinal polypeptide (VIP), substance P (SP), calcitonin gene-related peptide (CGRP), Leu5-enkephalin (LENK) and serotonin (5-HT) were analysed under a confocal laser scanning microscope. Profound differences in the neurochemical features of the nerve terminals between the ganglia were observed. Moreover, there were also distinct differences in the chemical coding of nerve fibres associated with the particular populations and subpopulations of neurons within the ganglia. In both ganglia, nearly all adrenergic and cholinergic neurons were supplied with VAChT-positive nerve fibres (putative preganglionic fibres). However, in the CaMG, they were more numerous and, in contrast to the APG, many of them also stained for VIP. In the APG, a great number of nerve terminals expressed immunoreactivity to SP and CGRP (putative collaterals of sensory neurons). Interestingly, they densely supplied almost exclusively adrenergic neurons. SP-positive nerve fibres were moderate in number in the CaMG, but, in addition to VAChT-IR nerve terminals, the most numerous populations of nerve fibres in this ganglion were those expressing highly colocalized immunoreactivities to CGRP and LENK, and those which stained for 5-HT (putative processes of enteric neurons). However, these fibres supplied almost exclusively larger, intensely stained for TH and clustered adrenergic neurons. This diversity of the nerve terminals reflects the complexity of nerve circuits involved in the innervation of structures supplied by neurons in the porcine CaMG and APG. It also demonstrates the importance of nerve inputs for the proper function of autonomic neurons and thus their target tissues.

The influence of inflammation on the expression of neuropeptides in the ileum-projecting primary sensory neurones in the pig

In the present study the ELISA test was used to investigate the influence of chemically-induced ileitis on the dorsal root ganglia (DRG) neurons in the pig. The preliminary retrograde fluorescent tracing study revealed that ileum-projecting sensory neurones (IPN) are located in the thoracic ganglia (Th; Th8-Th13). The ileum wall in experimental (E) pigs was subjected to multiple injection with 4% paraformaldehyde to induce inflammation, while in the control (C) animals the organ was injected with 0.1 M phosphate buffer. Three days later the DRGs (Th8-Th13) collected from all the animals were evaluated for VIP, SP, CGRP, NPY, GAL and SOM content with an ELISA test. It was found that the inflammation increased clearly the tissue level of SP, GAL and SOM.

Distribution of neurons containing leptin receptors in the hypothalamus of the pig

Leptin, secreted by white adipocytes, has profound feeding, metabolic, and neuroendocrine effects. Leptin acts on the brain, but specific anatomical sites and pathways responsible for mediating these effects are still unclear. We have systematically examined the distribution of leptin receptor containing neurons in the porcine hypothalamus by means of immunohistochemical staining methods. Leptin receptor immunoreactivity (OBR-IR) was observed in both the preoptic area and anterior hypothalamic area. No immunoreactive structures were found in the median eminence. Only single, small neurons were observed in the arcuate nucleus. The most abundant OBR-IR cell bodies were located in the supraoptic nucleus. In the paraventricular nucleus, OBR-IR neurons were moderate in number. Single, dispersed neurons were found in the ventromedial nucleus. These findings indicate that there are distinct OBR-IR neuronal populations in the porcine hypothalamus and leptin not only plays an integrative role in feeding behavior, but also in neuroendocrine activity.

Characterization of afferent and efferent galanin-containing nerve fibres in the porcine ovary

Double-labelling immunofluorescence combined with retrograde tracing revealed three subpopulations of galanin-immunoreactive nerve fibres innervating the porcine ovary. The first group originated in ipsilateral dorsal root ganglia Th11-L5 and exhibited colocalization with substance P-, but not with tyrosine-hydroxylase- or dopamine-beta-hydroxylase-immunoreactivity. These fibres supplied primordial follicles and large arteries of the ovarian hilus. The second group, arising from the sympathetic inferior mesenteric ganglion, was galanin-immunoreactive, but non-reactive to substance P-, dopamine-beta-hydroxylase- or tyrosine-hydroxylase-antisera. Fibres of this type were sparsely distributed in the ovarian cortex. They were observed in connection with small cortical arterioles or in the ovarian cortical stroma. The third group of galanin-containing nerve terminals originated from postganglionic neurons located in sympathetic chain ganglia Th15-L3 and S1. Most of them contained tyrosine-hydroxylase- and dopamine-beta-hydroxylase-immunoreactivity. This subset of galanin-positive nerve fibres was the least frequent and was almost exclusively associated with cortical arterioles. The findings are indicative of an involvement of galanin in autonomic and sensory neuronal functions in the ovaries, possibly control of follicle maturation and blood flow.

Distribution, immunohistochemical characteristics and nerve pathways of primary sensory neurons supplying the porcine vas deferens

The present study investigated: (1) the distribution and chemical coding of primary sensory neurons supplying the vas deferens in juvenile pigs by the use of retrograde tracing combined with double-labelling immunofluorescence, (2) nerve pathways from dorsal root ganglia (DRG) to the vas deferens by means of denervation procedures involving transection of the hypogastric or pelvic nerve combined with a retrograde tracing method, and (3) possible interactions of the substance P (SP)/calcitonin gene-related peptide (CGRP)-immunoreactive varicose nerve fibres on vas deferens projecting neurons (VDPN) in the anterior pelvic ganglion (APG). The vast majority of VDPN were found mainly in the lumbar L2, L3 and sacral S2, S3 pairs of DRG and showed a clear ipsilaterally organized projection pattern. Immunohistochemistry revealed that most of these neurons contained SP and/or CGRP, occasionally coexpressed with galanin. Interestingly, pronounced differences in the expression of SP and/or CGRP were observed between the lumbar and sacral VDPN in that most of the lumbar but less than half of the sacral neurons stained for these peptides. Denervation experiments showed that the neurons located within the lumbar DRG project through the ipsilateral hypogastric nerve, whereas those found within the sacral DRG send their processes through the ipsilateral and contralateral pelvic nerve. In the nerve-lesioned animals, especially in those with the hypogastric nerve cut, a dramatic reduction in the number of SP and/or CGRP-containing nerve terminals surrounding the efferent VDPN within the APG was observed. This study has disclosed the distribution and, for the first time, chemical coding and nerve pathways of vas deferens-projecting primary sensory neurons in a mammalian species, the pig. The results obtained also provide some novel information about the possible morphological and functional relationship between vas deferens-projecting primary sensory and pelvic efferent nerve cells.

Noradrenergic and peptidergic innervation of the mammary gland in the immature pig

The presence and pattern of coexistence of some biologically active substances in nerve fibres supplying the mammary gland in the immature pig were studied using immunohistochemical methods. The substances studied included: protein gene product 9.5 (PGP), tyrosine hydroxylase (TH), somatostatin (SOM), neuropeptide Y (NPY), galanin (GAL), calcitonin gene-related peptide (CGRP) and substance P (SP). The mammary gland was found to be richly supplied by PGP-immunoreactive (PGP-IR) nerve fibres that surrounded blood vessels, bundles of smooth muscle cells and lactiferous ducts. The vast majority of these nerves also displayed immunoreactivity to TH. Immunoreactivity to SOM was observed in a moderate number of nerve fibres which were associated with smooth muscles of the nipple and blood vessels. Immunoreactivity to NPY occurred in many nerve fibres associated with blood vessels and in single nerves supplying smooth muscle cells. Solitary GAL-IR axons supplied mostly blood vessels. Many CGRP-IR nerve fibres were associated with both blood vessels and smooth muscles. SP-IR nerve fibres richly supplied blood vessels only. The colocalization study revealed that SOM, NPY and GAL partly colocalized with TH in nerve fibres supplying the porcine mammary gland.