Immunoreactivity of glutamine synthetase in satellite glia around various subpopulations of lumbar dorsal root ganglia neurons in adult rats treated with monosodium glutamate

Satellite glial cells (SGCs), involved inter alia in glutamate (Glu) metabolism, form a glial sheath around sensory neurons of dorsal root ganglia (DRGs). SGCs show a presence of glutamine synthetase (GS) which transform uptaken Glu into glutamine (Gln). In DRGs, this aminoacid is used mainly by small neurons which are able to synthetize substance P (SP) that play a crucial role in nociception. The aim of the study was to define the influence of monosodium glutamate (MSG) on GS immunoreactivity in satellite glia around various subpopulations of neurons including SP immunopositive cells in DRGs of adult rats. The studies were carried out on lumbar DRGs slides in rats which received subcutaneous injection of saline solution (control group) or 4 g/kg b. w. of MSG (MSG group). Immunofluorescence reactions were conducted with use of anti-GS and anti-SP antibodies. Administration of MSG to adult rats increased the GS immunoexpression in SGCs. In rats receiving MSG, a number of small neurons with GS-immunopositive glial sheath was not altered when compared to control individuals, whereas there was a statistically significant increase of GS immunoexpression in SGCs around large and medium neurons. Moreover, in these animals, a statistically significant increase in the number of small SP-positive neurons with GS-positive glial sheath was observed. SP is responsible for transmission of pain, thus the obtained results may be useful for further research concerning the roles of glia in nociceptive pathway regulation.

Developmental changes in tibia and humerus of goose: morphometric, densitometric, and mechanical analysis

The skeletal system of young animals undergoes a series of intensive and rapid changes. In this study, we aimed to verify the hypothesis that geese exhibit a distinct pattern of bone growth compared to gallinaceous species. Specifically, we hypothesised that geese would experience an accelerated growth rate in the humerus bone, which can be attributed to the increased wing mobility facilitated by their rearing in free-range systems. This need for access to both ground and water environments contributes to the unique demands placed on their skeletal development. We focused on evaluating the mechanical properties and geometry of the humerus as the forelimb bone, and the tibia as the hindlimb bone. The 320 geese used in this study were divided into 12 groups according to sex (females and males) and age (0-,1-,3-,6-,8-,12-,14-week-old). To assess bone mechanical properties, a three-point bending test was performed, along with densitometry and morphological measurements. The tibiae of the geese showed the most intensive growth until 6 weeks of age and then stabilised. The wing bones (humerus) showed only slight changes in the first weeks after hatching, and then a rapid growth between the third and sixth week, both in terms of mechanical and morphological properties. This is most likely due to a change in the geese's living environment during this period, i.e., allowing them to leave their enclosures and enter open space, which gives them the opportunity to use their wings, resulting in the rapid growth of the wing bones to support increasing muscle mass in this area. This study increases our understanding of bone growth and development in domesticated birds, specifically waterfowl species, and highlights the importance of rearing methods on the proper bone development and functionality of the entire skeletal system, and thus, on their welfare.

Prenatal acrylamide exposure results in time-dependent changes in liver function and basal hematological, and oxidative parameters in weaned Wistar rats

Acrylamide (ACR) is a toxic compound commonly found in fried, baked and heat-processed starchy foods. The current study investigated the time-dependent effects of maternal exposure to non-toxic ACR doses on the oxidative stress, liver function, and basal blood morphology of the rat offspring. Pregnant, Wistar rats were randomly divided into the control group or the groups administrated with ACR (3 mg/kg b.w./day): long exposure for 15 days, medium exposure for 10 days and short exposure for 5 days during pregnancy. Body mass, blood morphology and hematology, serum concentrations of growth hormone, IGF-1, TNF-α, IL-1β, IL-6 and insulin, liver histomorphometry, liver activity of beclin1, LC2B and caspase3, markers of oxidative stress and the activity of antioxidative enzymes in blood serum and the liver were measured in offspring at weaning (postnatal day 21). Even short prenatal exposure to ACR led to oxidative stress and resulted in changes in liver histomorphometry and upregulation of autophagy/apoptosis. However, the most significant changes were observed following the long period of ACR exposure. This study has shown for the first time that ACR is responsible for changes in body mass in a time-dependent manner, which could lead to more serious illnesses like overweight and diabetes later in life.

Immunoreactivity of acetylcholinesterase and M1 muscarinic receptors in the hippocampus and striatum of rats treated with Rebaudioside A

Rebaudioside A (RebA) is a steviol glycoside used for production of sweeteners. It was shown that the glycosides affect memory and learning processes. The aim of the study was to investigate neurons immunoreactive for acetylcholinesterase (AChE) and M1 muscarinic receptors (mAChRs-M1) of the hippocampal CA1 and CA3 fields and striatal caudateputamen (CP) and globus pallidus (GP) in rats receiving RebA. RebA was administrated to adult rats for 45 days in dilutions of 1 mg and 2 mg RebA/ml water. Indirect peroxidase-antiperoxidase immunohistochemical reaction was conducted on frontal sections containing the hippocampus and striatum with use of antibodies against AChE and mAChRs-M1. Immunoreactive for the studied proteins neurons were morphologically and morphometrically assessed in hippocampal CA1 and CA3 fields and in CP and GP. Microscopic observations did not reveal significant changes in morphology of immunoreactive neurons, which suggests no neurotoxic effect of the studied glycoside on these cells. Morphometric analyses revealed an increase in the density of AChE and mAChRs-M1 immunoreactive neurons. A decrease in reaction intensity of AChE-positive neurons was also demonstrated in the hippocampal CA1 field and in GP. In contrast, an increase in reaction intensity of mAChRs-M1-positive neurons was found in CA1, CA3 fields and in CP and GP. The results of our preliminary studies indicate that RebA administrated to rats has an impact on cholinergic neurons in the studied area. The results suggest a possible increase in the activity of the cholinergic system, responsible for memory and learning processes, after administration of RebA.

Insulin receptors in the CA1 field of hippocampus and selected blood parameters in diabetic rats fed with bilberry fruit

INTRODUCTION

Bilberry fruit is believed to be a promising factor in the treatment of diabetes mellitus. Chronic hyperglycaemia affects the function of the central nervous system, which may be manifested as changes in hypothalamic insulin signalling.

MATERIAL AND METHODS

Using DPPH and ABTS assays, total phenolic content in bilberry fruit and its antioxidant activities were examined. The selected biochemical parameters of blood (glucose, fructosamine, total cholesterol, HDL-cholesterol, LDL-cholesterol and triglycerides), as well as the expression of insulin receptors, were studied in the hippocampal CA1 field of healthy and diabetic (streptozotocin-induced; 60 mg kg-1 body weight) Wistar rats fed with bilberry fruit (16 g kg-1 body weight per day; 6 weeks), as well as of the corresponding control groups.

RESULTS

Biochemical analyses revealed ambiguous results, but a significantly (P<0.05) decrease in the level of LDL-cholesterol was observed in the group of healthy rats supplemented with bilberry pulp after 6 weeks of the treatment. There was also a difference (P<0.05) in the level of LDL-cholesterol in the mentioned healthy animals fed with bilberry, versus the healthy control group. An increased number of insulin receptors-immunoreactive neurons as well as nerve fibres in the CA1 field of diabetic rats fed with bilberry fruit was also found.

CONCLUSIONS

An inclusion of bilberry fruit in the daily diet during the course of diabetes can lead to plasticity of hippocampal neurons/nerve fibres, manifested by changes in insulin receptors expression. Whether or not the observed changes had protective effects (by reducing damages caused by diabetes mellitus) on the function of the central nervous system neurons needs further study.

Immunohistochemical study on the expression of biologically active substances in the endocrine pancreas of the European bison

Previous morphological studies of mammalian pancreatic islets have been performed mainly in domestic and laboratory animals. Therefore, the present immunohistochemical investigation was conducted in a wild species, the European bison, using antibodies against glucagon-like peptide-1 (GLP1), glucagon, insulin and somatostatin. Morphological analyses revealed that the mean area of the endocrine pancreas constituted 2.1±0.1% of the whole area of the pancreas, while the mean area of a single pancreatic islet was 13301.5±686.5 µm2. Glucagon-immunoreac- tive cells accounted for 22.4±1.1% and occupied 19.4±0.4% of the average islet area. As many as 14.3±1.4% of pancreatic islet cells were shown to express GLP1, which constituted 12.6±0.8% of the mean area of the islet. Insulin expression was confirmed in 67.6±0.7% of pancreatic islet cells, which represented 62.3±4.9% of the mean total area of the pancreatic islet. As many as 8.5±1.3% of cells stained for somatostatin. The somatostatin-immunoreactive cell area was 4.9±0.3% of the mean pancreatic islet area. In summary, we have determined in detail for the first time the morphometry and islet composition of the European bison pancreas. The distri- bution patterns of immunoreactivities to the substances studied in the European bison show many similarities to those described in other ruminant species.

Modern Hybrid Rye, as an Alternative Energy Source for Broiler Chickens, Improves the Absorption Surface of the Small Intestine Depending on the Intestinal Part and Xylanase Supplementation

The current study investigated the effects of the inclusion of modern hybrid rye (Brasetto variety) to a corn-wheat-based diet, with or without xylanase, on the absorptive surface of the small intestine of broilers. A total of 224 one-day-old male Ross 308 broiler chicks were randomly divided into four experimental groups with seven replicate cages of eight birds/replicate. A 2 × 2 factorial study design was used, with rye inclusion (0% or 20%) and xylanase supplementation (0 or 200 mg/kg of feed) as factors. Inclusion of rye increased duodenal and ileal crypt depth, villi height, the villus-to-crypt ratio and absorption surface area (p < 0.05), and ileal mucosa thickness and crypt width (p < 0.05). Xylanase supplementation attenuated the effects of rye in the duodenum and ileum and decreased the villi height and villus-to-crypt ratio in the jejunum (p < 0.05). Rye and xylanase had no effect on the spatial distribution of claudin 3 and ZO-1 protein, but xylanase supplementation reduced the amount of claudin 3 in the duodenum and jejunum (p < 0.05). The findings of this study indicate that 20% inclusion of modern hybrid rye to the diets of broilers improved the structure of the duodenum and ileum, but these effects were attenuated by xylanase supplementation.

Colocalization pattern of cocaine- and amphetamine-regulated transcript peptide and parvalbumin immunoreactivity in the hippocampus proper of the chinchilla

This study set out to investigate, for the first time, the distribution and colocalization pattern of cocaine-and amphetamine-regulated transcript (CART) and one of the calcium binding- -proteins: parvalbumin (PV) in the chinchilla's hippocampus proper (HP). HP, consisting of Ammon's horn (CA) and the dentate gyrus (DG), is an important component of the limbic system, involved in learning and memory processes. CA showed a higher immunoreactivity of CART (-IR) compared to DG. CART-IR neurons were mainly observed in the molecular layer of DG and in the pyramidal layer of CA. CART-IR fibers were present in the granular layer; in the hilus numerous mossy fibers were detected, while in the molecular layer CART-IR fibers were not found. In all CA fields (CA1-CA3), CART-IR fibers were only present in the lacuno- sum-molecular layer. Immunofluorescence with double- labeling showed that only CART-IR cells stained positive for PV, whereas in CART-IR fibers there was no PV-positive reaction. Our research supplements missing knowledge about the distribution and colocalization pattern of CART with PV in the chinchilla's hippocampus, and also provides a better understanding of the similarities and differences among individuals of the same species and also with other mammals.

Histomorphometrical changes in intestine structure and innervation following experimental fumonisins intoxication in male Wistar rats

Fumonisins are highly toxic metabolites produced by Fusarium proliferatum and Fusarium verticillioides. Little is known about the effects of a chronic low level of fumonisins on intestinal structure and innervation in monogastric animals, even though the intestine is the first organ exposed to fumonisins. The influence of the most prevalent strains of fumonisins, FB1 and FB2, on intestinal and liver morphology, the enteric nervous system and intestinal epithelial cell prolif- eration was investigated in an experimental rat model of fumonisin intoxication. Adolescent (5-weeks-old), male Wistar rats were randomly divided into a control group (C group) not treated with fumonisins or intoxicated with fumonisins (FB group). FB1 together with FB2 were daily administered intragastrically at a dose of 90 mg/kg body weight for 21 days. The damaging effect was assessed by determination of the activity of ALAT and AspAT. Samples from the small intes- tine and liver were taken and blood samples were collected to determine the activity of gamma- -glutamyl transferase (GGT) and amylase. The exposure to FBs resulted in histopathological degenerative alterations in hepatocytes, including mild vacuolar degeneration and ballooning. FB exposure was also toxic in the duodenum and jejunum, where significant changes in morphology, cell proliferation, collagen wall fibres and innervation were observed. Taken together, the results obtained strengthen the hypothesis that chronic exposure to FBs could induce intestinal damage, including damage to the enteric nervous system and may have consequences for general health.

The influence of bilberry fruit on memory and the expression of parvalbumin in the rat hippocampus

Therefore, the aim of the present study was to evaluate the possible effect of bilberry fruit (Vaccinium myrtillus L.) supplement in a daily diet on the cognitive behaviour of the rats and the expression of paravalbumin (PV) in populations of hippocampal neurons. It has been postulated that the antioxidants present in bilberry fruit may act as neuroprotective factors playing also a significant role as memory enhancements. Forty Wistar rats with a similar average body weight (460 ± 0.4 g) were divided into four groups (n=10 per group). The control group received standard feed (210 g/week), whereas animals of experimental groups received standard feed supplemented with bilberry (per os) at consumed doses of 2 g (group I), 5 g (group II), and 10 g/kg b.w./ /day (group III). After three months of feeding with bilberry, the modified elevated plus-maze test (mEPM) was performed. After 32 weeks of feeding, brains were collected and PV-immunoreactive (ir) neurons were immunohistochemically visualized. In the modified elevated plus-maze test, transfer latency examined 2 h and 24 h after the acquisition session was significantly shorter (p⟨0.05) in the group II in comparison with the control group. In CA1 and CA2/CA3 hippocampal fields as well as dentate gyrus of all experimental groups, a significant (p⟨0.05) decrease in number of PV-ir neurons were found. In relation to the control group, the mean subpopulation of PV-ir neurons found in groups II and III were significantly reduced. The subpopulations of PV-ir neurons found in DG of all experimental groups were significantly reduced in comparison to the control. In conclusion the in the present paper we demonstrated a relationship between the diet rich in a bilberry fruit and process of memory as well as numbers of calcium- binding protein-expressing hippocampal neurons. Our results may be source of basic knowledge for further research aiming at neuroprotective role of the bilberry fruit.

Analysis of mechanical properties of bones and tendons shows that modern hybrid rye can be introduced to corn-wheat based diet in broiler chickens as an alternative energy source irrespective of xylanase supplementation

This study focused on analyzing the effects of inclusion of modern hybrid rye to corn-wheat diet on mechanical properties of bones and tendons. A total of 224 broiler chickens were fed a diet without rye inclusion or a diet containing 15% of hybrid rye cv. Brasetto. The diets were either unsupplemented or supplemented with xylanase (minimum activity 1000 FXU/g, dose 200 mg/kg of feed). Each dietary group consisted of 56 birds. On day 42, selected chickens (n = 7 from each group) were slaughtered. Tibia were analyzed for mineralization, geometry, and biomechanical characteristics of bone mid-diaphysis. The mechanical properties of digital flexor III tendon were also assessed. Bone mineral density and bone ash percentage did not differ when both diets were given without xylanase. Enzyme supplementation increased bone mineral density (P < 0.01) in both dietary groups, whereas bone ash percentage (P < 0.01) increased only for corn-wheat diet. Rye inclusion had no effect on bone mid-shaft geometrical traits related to tibia weight-bearing capacity (cross-sectional area, cortical index, and mean relative wall thickness). Performed bending test showed no effect of hybrid rye inclusion on bone mechanical endurance. When xylanase was supplemented, bone length (P < 0.01) and weight (P < 0.05) decreased, whereas yield load (P < 0.01), stiffness (P < 0.05), Young modulus (P < 0.05), elastics stress (P < 0.01), and ultimate stress (P < 0.01) increased, irrespective of rye presence. The tendon tensile strain test showed that in corn-wheat diet enzyme supplementation positively influenced rupture force (P < 0.05) and tendon stiffness (P < 0.01). Xylanase supplementation increased the value of energy required to tendon rupture, irrespective of rye inclusion (P < 0.05). Study showed that modern hybrid rye varieties can be introduced to corn-wheat diets of broiler chickens in the aspect of animal welfare related to the development and homeostasis of musculoskeletal system, irrespective of xylanase supplementation. The enzyme addition positively affected biomechanical properties of bones and tendons.

The effect of obesity on the bone morphometry and histomorphometry in male and female Wistar rats

The study was undertaken to determine the effect of continuation or changes of the diet on the morphometry and histomorphometry of bone in male and female Wistar rats with experimen- tally induced obesity by high energetic diet. Sixty-four 90-day-old Wistar rats obtained from obese parents (16 male, 16 female) and control parents (16 male, 16 female) were used in this study. After 21 days of the baby period, rats were divided into four groups: obese rats fed with high energy feed (F/F), control rats fed with a standard diet (C/C), obese rats with changed diet from high energy diet to control diet (F/C) and control rats with changed diet from control diet to high energy diet (C/F). After 90 days of experimental feeding, the rats were sacrificed. Thereafter, body weight and the isolated humerus were measured and next, the histological stainings and counts were done. Our results revealed that change in the parent's diet from F to C in the female leads to increased bone growth length and reduction of body weight in female and male. Reverse diet changes (from C to F) lead to decreased bone length only in the female. Moreover, the con- tinuation by offspring of both sexes with a high-energy diet contributes to a reduction in osteo- cytes, reduction in bone marrow cavity and cortical expansion, but a change in nutrition from parents' standard diet to high-energy diet leads to increase in osteocytes dimensions. The contin- uation of feeding with F diet promotes the accumulation of adipocytes in the bone marrow in female and male, and correction of nutrition from F to standard diet leads to a reduction in their number in the bone marrow compared to groups continuing feeding with high-energy diet.

Effect of feeding with bilberry fruit on the expression pattern of αCaMKII in hippocampal neurons in normal and diabetic rats

αCaMKII, widely occurring in the central nervous system, plays a significant role in cognitive processes. It is well known that diabetes is a risk factor that may trigger brain atrophy, cognitive dysfunction and finally lead to memory loss. Antioxidants richly present in bilberry fruits are believed to have significant effects on diabetes-related brain dysfunctions mainly due to their abilities to modulate neurotransmitter release that lead to reduction of the negative impact of free radicals on cognitive processes. The aim of the present research was to immunohistochemically investigate the expression patterns of αCaMKII in hippocampal neurons from non-diabetic, diabetic and diabetic rats fed with an extract of bilberry fruit. The obtained results show that in comparison to the control group, in diabetic rats hippocampal neurons immunoreactive (ir) to αCaMKII were swollen and the lengths of the neuronal fibres were reduced. Further study shows that in diabetic rats fed with bilberry fruit, αCaMKII-positive nerve fibres were significantly longer when compared to the groups of diabetic and control rats. Additionally, we observed statistically significant changes in the average larger diameter of αCaMKII-ir hippocampal neurons between groups of diabetic rats (with vs. without supplement of bilberry fruit). The results of the present work suggest that antioxidants present in bilberry fruits influence the morphology of and possibly exhibit beneficial and neuroprotective effects on hippocampal neurons during diabetes. It is likely that changes in the appearance of αCaMKII-expressed hippocampal neurons may reflect the diabetes-evoked rise in Ca2+ level in the cerebral nerve terminals. The present research extends our knowledge of preventive mechanisms for cognitive dysfunctions occurring in the brain during diabetes.

Distribution and immunohistochemical characteristics of cocaine- and amphetamineregulated transcript-positive nerve elements in the pelvic ganglia of the female pig

Cocaine- and amphetamine-regulated transcript (CART) peptides are widely expressed not only in the brain but also in numerous endocrine/neuroendocrine cells as well as in neurons of the peripheral nervous system. The present study investigated the distribution patterns of CART-like immunoreactivity in the pelvic plexus (PP) of the female pig. The co-expression of CART with principal neurotransmitter markers: choline acetyltransferase (ChAT), tyrosine hydroxylase (TH), serotonin (5-HT) or biologically active neuropeptides: pituitary adenylate cyclase-activating polypeptide (PACAP), substance P (SP), calbindin was analyzed using double immunohistochemical stainings. Amongst neurons immunopositive to Hu C/D panneuronal marker as many as 4.1 ± 1.2% in right and 4.4 ± 1.6% in left pelvic ganglia were found to express CART. The vast majority of CART-IR ganglionic neurons were predominantly small in size and were evenly scattered throughout particular ganglia. Immunoreactivity to CART was also detected in numerous nerve terminals (which frequently formed pericellular formations around CART-negative perikarya) as well as in numerous nerve fibres within nerve branches interconnecting the unilateral pelvic ganglia. Immunohistochemistry revealed that virtually all CART-IR neurons were cholinergic in nature and CART-IR basket-like formations frequently encircled TH-positive/CART-negative perikarya. None of CART-IR ganglionic neurons showed immunoreactivity to SP, PACAP, 5-HT or calbindin. CART-IR nerve fibres ran in a close vicinity to serotonin-containing cells or faintly labelled SP-expressing neurons. On the other hand, PACAP-IR, SP-IR (but not 5-HT-positive) nerve terminals were found to run in close proximity to CART-IR neurons. Our results indicate that: 1) CART present in PP may influence the activity of pelvic ganglionic neurons/SIF cells, 2) PP should be considered as a potential source of CART-like supply to pelvic viscera and 3) functional interactions between CART and SP or PACAP are possible at the periphery.

Immunocytochemical detection of calretinin in the claustrum and endopiriform nucleus of the chinchilla

Calretinin (CR) as a buffer and sensor protein plays an important role in regulatory processes of Ca²⁺ and anty-apoptotic cellular protection. In the present study, immunohistochemical peroxidase-antiperoxidase (PAP) method was used in order to determine the numbers, morphology, morphometry and distribution pattern of CR in neurons of the chinchilla's claustrum (Cl) and endopiriform nucleus (EN). In Cl and EN the presence of several classes of neurons with different immunoreactivity to CR was found. In Cl, CR-immunoreactive (IR) neurons were predominantly found in close vicinity to insular border while CR-IR neurons were evenly scattered throughout EN. In general, immunoreaction to CR was observed in neuronal cytoplasm, nucleus and in fibres-like nerve extensions. Statistical analysis showed the differences between average large diameter as well as cross-sectional area of CR-IR neurons present in Cl and EN. It is suggested, that CR acting as a calcium binding protein may play a role in neuronal network. Further co-localization studies are necessary to fully elucidate neurophysiology and neuropathology of the chinchilla's Cl and EN neurons.

Pituitary adenylate cyclase-activating peptide-27 (PACAP-27) is co-stored with galanin, substance P and corticotropin releasing factor (CRF) in intrapancreatic ganglia of the sheep

Pituitary adenylate cyclase activating polypeptide (PACAP) is a neuropeptide existing in two variant forms (of either 27 or 38 residues), widely present in numerous organs and evoking multiple effects both in the central and peripheral nervous systems. The present study was undertaken to evaluate the distribution pattern of PACAP-27 expression in the ovine pancreas. Using double immunohistochemical stainings co-localizations of PACAP-27 with galanin, SP or CRF were studied in intrapancreatic neurons. In intrapancreatic ganglia, immunoreactivty to PACAP-27 was found in 87.6 ± 5.4% of PGP 9.5-positive intrapancreatic neurons but not in intraganglionic nerve fibres. Numerous PACAP-27-immunoreactive nerve terminals were also observed between pancreatic acini and around small arterioles. No immunoreactivity to PACAP-27 was found in the endocrine pancreas. In 42.9 ± 6.2% of PACAP-27-immunoreactive intrapancreatic neurons the expression of galanin was also found. Statistically lower subpopulation (12.4 ± 4.0%) of intrapancreatic neurons exhibited simultaneously the immunoreactivity to PACAP-27 and SP. The expression of CRF was detected in the relatively smallest group (3.2 ± 1.4%) of PACAP-27-positive intrapancreatic neurons. The present results suggest that in the ovine pancreas PACAP-27 may play an important role as mediator of pancreatic functions. In PACAP-related pancreatic activities, a modulatory role of galanin, SP and to a lower extend of CRF is also likely.

Co-expression patterns of cocaine- and amphetamine-regulated transcript (CART) with neuropeptides in dorsal root ganglia of the pig

In the present study the neuronal distribution of CART was evaluated immunohistochemically in porcine dorsal root ganglia (DRGs). In co-localization studies the co-expression patterns of CART with SP, CGRP, galanin, CALB and LENK were investigated by means of triple immunohistochemical stainings. In porcine DRGs, the expression of CART was found in approximately 5% of primary sensory neurons. The vast majority (ca. 95%) of CART-immunoreactive (IR) neurons were small and middle sized, and only 5% were categorized as large. CART-IR neurons additionally exhibiting the presence of SP/CGRP (ca. 12%), SP/CALB (ca. 12%), SP/LENK (ca. 5%) were found. The vast majority of CART-IR/CGRP-IR neurons did not display immunoreaction to SP (ca. 60%). Subclasses of CART-IR/LENK-IR/SP-negative (ca. 5%), as well as CART-IR/CALB-IR/SP-negative neurons (ca. 10%), were also visualized. In addition, CART-IR neurons with no immunoreactivities to any of the neuropeptides studied were also shown. In porcine DRGs none of the CART-IR neurons exhibited the presence of galanin. The results obtained in the study suggest that CART may functionally modulate the activity of the porcine primary sensory neurons. It is concluded that co-expression of CART with CGRP, SP, LENK and CALB in subsets of the pig L1-L6 DRGs neurons provide anatomical evidence for a CART role in pain processing.

Immunolocalization of NOS, VIP, galanin and SP in the small intestine of suckling pigs treated with red kidney bean (Phaseolus vulgaris) lectin

Lectins belong to a family of glycoproteins that can act both beneficially and detrimentally on the morphology of the small intestine. The aim of the study was to determine whether experimental treatment with red kidney bean (Phaseolus vulgaris) lectin influences the chemical code of the small intestine nervous system of suckling pigs. The immunolocalization sites of vasoactive intestinal polypeptide (VIP), nitric oxide synthase (NOS), substance P (SP) and galanin were determined in control and lectin-treated animals. In all segments of the small intestine (duodenum, jejunum, ileum), the subpopulations of VIP-, NOS-, SP- and galanin-immunoreactive (IR) myenteric neurons were unchanged. After lectin stimulation, increased proportions of NOS-IR and decreased numbers of VIP-IR submucous neurons/mucosa innervating nerve fibers were observed in the duodenum, jejunum and ileum. In lectin-treated animals down-regulation of submucous neurons expressing SP and up-regulation of galanin-IR submucous neurons were seen in the duodenum and jejunum (but not in the ileum). The distribution patterns of NOS-IR, galanin-IR and SP-IR nerve fibers supplying the duodenum, jejunum and ileum of the lectin-treated animals showed no substantial differences in relation to control piglets. We conclude that exposure to red kidney bean (P. vulgaris) lectin substantially changes the chemical content of VIP, NOS, SP and galanin in submucous neurons of the small intestine. These results are in line with previous findings outlining the key role(s) of these substances in enteric neuroplasticity processes and may constitute the basis for further functional studies on maturation of the gut.

Immunoreactivity to cocaine- and amphetamine-regulated transcript in the enteric nervous system of the pig and wild boar stomach

Cocaine- and amphetamine-regulated transcript (CART) is a recently discovered peptide inducing strong anxiogenic-like effect. CART distribution and its role(s) at periphery are not well understood. Immunohistochemisty was utilized to investigate the distribution patterns of CART in the stomach of the pig and wild boar. Double immunohistochemisty was applied to elucidate whether CART-immunoreactive (IR) neuronal elements coexpress galanin, substance P (SP) and neuropeptide Y (NPY). In the pig stomach, different proportions of CART-IR myenteric neurons were found in the antrum (42.3 ± 3.5%), corpus (18.0 ± 1.9%) and pylorus (33.2 ± 3.0%). CART-IR myeneric neurons were also found in the antrum, corpus and pylorus of the wild boar stomach (41.7 ± 3.2, 36.0 ± 2.2 and 35.8 ± 3.5%; respectively). In both species, none of gastric submucous neurons were CART-IR; however, CART-IR nerve fibres encircled submucous perikarya. In all portions of the pig and wild boar stomach, CART-IR nerve fibres were frequently found in the smooth muscle layer as well as in the lamina muscularis mucosae. In all regions of the pig and wild boar stomach, the expression of galanin and SP was found in CART-IR myenteric neurons and smooth muscle-supplying nerve fibres. CART/NPY coexpression was not found in the porcine stomach; however, in different regions of the wild boar stomach, subpopulations of CART-IR/NPY-IR myenteric neurons were noted. In conclusion, in this study, the existence and distribution patterns of CART in discrete regions of the pig and wild boar stomach were described in details. Colocalization studies revealed that in both animal species, a functional cooperation of CART with several neuropeptides is likely.

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.

Aquaporin 1 water channel is expressed on submucosal but not myenteric neurons from the ovine duodenum

Aquaporins are a large family of small integral membrane proteins that function as molecular water channels. Increasing evidence indicates that an aquaporin 1 (AQP1) water channel is present on the surface of discrete neuronal classes of the central as well peripheral nervous systems. The aim of the present study has been to immunohistochemically localize AQP1 in the enteric nervous system (ENS) of the sheep duodenum. Specific antibodies to vasoactive intestinal polypeptide (VIP) and substance P (SP) were also used to biochemically determine possible function(s) of AQP1-positive enteric neurons. The expression of AQP1 in neuronal cell cultures has been also studied. Under normal conditions, approximately 30% of submucosal neurons exhibit the presence of AQP1 water channels. Neither myenteric neurons nor enteric nerve fibres showed immunoreactivity to AQP1. The vast majority of AQP1-bearing submucosal neurons were immunoreactive (IR) to SP (but not to VIP). Moderate numbers of SP-IR as well as VIP-IR nerve fibres run in close vicinity to AQP1-positive small blood/lymphatic vessels. SP-positive as well as VIP-positive nerve fibres were regularly observed to be in close contact with AQP1-positive submucosal neurons. After 3, 6 and 9 days of in vitro culturing, respectively, myenteric neurons still exhibited no presence of AQP1 channels. The obtained results indicated that in ENS of the ovine duodenum the expression of AQP1 is species-related and predominantly seen in a significant subpopulation of probably sensory submucosal neurons. Since we show no upregulation of AQP1 channels in cultured myenteric neurons we suggest that AQP1 is not a significant factor involved in environmental adaptation of myenteric neurons to the artificial conditions.

Distribution and chemical coding of calretinin- and calbindin-expressing enteric neurons in the duodenum of the sheep

Recent decades has brought significant advances in our knowledge of the chemical coding and function of enteric neurons. Calcium ions are important second messenger involved in many aspects of neuron physiology. In the present study, we analyzed immunohistochemically the presence of calcium binding proteins (calretinin and calbindin) in various subpopulations of enteric neurons from the ovine duodenum. Ten percent of submucous neurons were immunoreactive (IR) to calretinin. The presence of calretinin was not detected in myenteric neurons. Calretinin-expressing nerve fibres were found in both myenteric and submucous ganglia, between the circular and longitudinal smooth muscle layers and in the lamina muscularis mucosae. Calretinin-IR submucous neurons did not exhibit the presence of SP, NPY and VIP. Co-localization of calretinin and serotonin was found only in a small number of submucous neurons. Calbindin was expressed in 35% of myenteric neurons and in 60% of submucous neurons. Nerve fibres containing calbindin were localized in myenteric and submucous ganglia where they frequently formed basket-like formations. Calbindin-positive nerve fibres emerging from myenteric ganglia ran between the circular and longitudinal smooth muscle layers. Immunoreactivity to calbindin was also visualized in the lamina muscularis mucosae, around mucosal glands and blood vessels. None of calbindin-IR myenteric neurons revealed immunoreactivity to SP, NPY, VIP and serotonin. Virtually all calbindin-expressing submucous neurons were SP-positive. In moderate numbers of submucous perikarya, co-incidence of calbindin and NPY, calbindin and VIP or calbindin and serotonin was observed. We conclude that in the ovine duodenum, the expression of calretinin and calbindin is species specific. Co-localization studies and distribution patterns indicate that in the duodenum of the sheep, calretinin and calbindin may be present in several functional subclasses of enteric neurons.

Immunodetection of cocaine- and amphetamine-regulated transcript in the rumen, reticulum, omasum and abomasum of the sheep

Enteric nerves harbour a wide array of neuropeptides playing a key role in the regulation of gastrointestinal tract functions. In this study, the distribution patterns of cocaine- and amphetamine-regulated transcript-immunoreactive (CART-IR) nerve fibres as well as the percentages of CART-positive enteric neurons were immunohistochemically assessed in the rumen, reticulum, omasum and abomasum of the sheep. Double staining were applied, to elucidate whether neuropeptide Y (NPY), vasoactive intestinal polypeptide (VIP), substance P (SP), somatostatin or serotonin co-exist in CART-IR gastric structures. In the rumen, reticulum, omasum and abomasum, a majority of myenteric neurons identified by immunoreactivity to Hu C/D were CART-positive (47.1 +/- 3.6%, 45.1 +/- 3.0%, 41.6 +/- 2.6% and 40.9 +/- 2.9% respectively). The smooth musculature of the forestomachs as well as abomasum was innervated with numerous CART-IR nerve fibres. Blood vessels-associated CART-positive nerve terminals were identified in the submucosa of the reticulum only. Lamina muscularis mucosae of the omasum and abomasum was moderately innervated with CART-IR nerve terminals. In the abomasum sparse CART-IR nerve fibres were seen between mucosal glands. A small population of endocrine cells of the abomasum also exhibited the presence of CART. All neuronal elements as well as endocrine cells IR to CART were negative to somatostatin and/or serotonin. No immunoreactivity to VIP, NPY and/or SP was found in myenteric ganglia-projecting CART-positive nerve fibres. The co-localization of CART with VIP, NPY and/or SP was regularly observed in myenteric neurons as well as the smooth muscle layer- and lamina muscularis mucosae-projecting nerve fibres. CART-IR nerve terminals located between mucosal glands of the abomasum frequently co-stored VIP, NPY and/or SP. Although the exact function of CART in the ovine forestomachs/stomach has to be elucidated, several potential functions (like enteric nerves protection) have been suggested.

Expression of Neuronal Nitric Oxide Synthase in the Pancreas of the Sheep

In numerous mammals, nitric oxide (NO) influences the activity of the exocrine and endocrine pancreas. In this study, immunocytochemistry was utilized to investigate the expression of neuronal nitric oxide synthase (nNOS) in the pancreas of sheep. In double immunocytochemical staining, the co-localization of nNOS with vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY) or substance P (SP) was studied. The presence of nNOS was confined to the intrapancreatic neurones (9.6 +/- 1.3%) as well as to nerve fibres of the endocrine pancreas and intrapancreatic ganglia. nNOS-immunoreactive (IR) neurones were round and oval in shape and predominantly (83.3 +/- 2.6%) belonged to the middle-size group (25-50 mum). Numerous, fine islets supplying nNOS-IR nerve terminals were devoid of VIP, SP or NPY. Moderately numerous, non-varicose nNOS-IR nerve fibres of intrapancreatic ganglia frequently expressed VIP or NPY, but not SP; 2.2 +/- 0.6% of nNOS-IR intrapancreatic neurones displayed lack of VIP, whereas 7.5 +/- 0.8% were VIP-IR. All nNOS-IR neurones were devoid of SP. The frequencies of nNOS-IR/NPY-IR and nNOS-IR/NPY-negative intrapancreatic neurones were 2.2 +/- 0.4% and 6.1 +/- 1.1%, respectively. Comparison with other mammals indicated that nitrergic innervation of the ovine pancreas is species-determined and may be a reflection of the ruminants' digestion specificity. The possible origin of nNOS-IR nerve fibres and functional significance of NO in the pancreas of sheep were discussed.

Cholinergic innervation of the pancreas in the sheep

Antibodies raised against vesicular acetylcholine transporter (VAChT) were applied to study the cholinergic innervation pattern of the pancreas of the sheep. To determine whether the cholinergic pancreatic neuronal elements contain tyrosine hydroxylase (TH), neuropeptide Y (NPY), vasoactive intestinal peptide (VIP) or substance P (SP) double immunocytochemistry was used. A moderate number of VAChT-immunoreactive (IR) nerve terminals were distributed between the acini, whereas only single cholinergic nerve fibres innervated the interlobular connective tissue. VAChT-positive nerve fibres supplying the endocrine pancreas were found only occasionally. The pancreatic blood vessels and ducts system were devoid of VAChT-containing nerve endings. All intrapancreatic neurons studied showed immunoreactivity to VAChT, but intrapancreatic ganglia were not innervated with cholinergic nerve fibres. The colocalization of VAChT and TH or VAChT and SP was detected in distinct populations of nerve fibres localized amongst the acini, but not within the islet nor in the connective tissue. Single VAChT-IR nerve terminals co-expressing NPY were distributed around the acini, islets as well as in the connective tissue septa. A moderate number of VAChT-IR/VIP-IR nerve endings were located in the exocrine pancreas, whereas the islets and connective tissue were innervated with VAChT/VIP-containing nerve fibres only occasionally. In the vast majority of VAChT-positive intrapancreatic perikarya the presence of TH was additionally found. A moderate number of VAChT-IR intrapancreatic perikarya co-expressed NPY, SP or VIP. The results of the present study demonstrate species-dependent cholinergic innervation pattern of the pancreas of the sheep. The co-localization of VAChT with the neuropeptides suggests the existence of functional interactions influencing the ovine pancreas (mainly exocrine) activity.

A co-localization study on the ovine pancreas innervation

The expression of DbetaH and several neuropeptides was investigated in neuronal elements of the ovine pancreas using double immunocytochemical stainings. Immunoreactivities to DbetaH, NPY, VIP and SP were seen to various extents in nerve terminals associated with the acini, islets, ducts, blood vessels, interlobular connective tissue as well as in the neurons of intrapancreatic ganglia. The expression of CGRP was limited to nerve fibers lying in the connective tissue septa, amongst the acini and in close vicinity to the pancreatic blood vessels. Single GRP-positive nerve endings were located around the acini, ducts and in the interlobular connective tissue. With the exception of the ductal system in a co-localization of NPY with DbetaH was frequently found in all regions of the pancreas. Moderately numerous blood vessel-associated VIP-positive nerve fibers as well as the vast majority of VIP-containing intrapancreatic neurons were found to co-express DbetaH. Single SP-immunoreactive (IR) nerve fibers of the exocrine pancreas and interlobular connective tissue as well as SP-positive intrapancreatic neurons additionally showed the presence of DbetaH. The co-localization of VIP and NPY was found in nerve terminals located around the blood vessels and acini, in the connective tissue septa as well as in numerous pancreatic neuronal perikarya. Rare nerve terminals located between the acini and around small blood vessels as well as several neurons of intrapancreatic ganglia were VIP-IR/ SP-IR. Simultaneous expression of SP and CGRP was found in nerve fibers supplying large pancreatic arteries and veins, interlobular connective tissue and, occasionally, around the acini. Throughout the pancreas the population of CGRP-positive nerve endings showed lack of VIP and NPY. In a moderate number of GRP-containing nerve fibers, a co-expression of NPY was noted. Nerve terminals containing both GRP and VIP were detected sporadically, whereas none of the GRP-positive nerve terminals showed expression of SP. We conclude that the presented noradrenergic as well as peptidergic innervation patterns of the ovine pancreas are species-dependent. On the basis of the occurrence of DbetaH, NPY, VIP and SP (alone or in combination) in pancreatic neuronal elements we can suggest that these substances presumably act as regulators of the endocrine and/or exocrine pancreas. Involvement of CGRP and GRP in the ovine pancreas physiology seems to be of minor importance. The co-localization study indicated that the pancreas of the sheep is innervated from several sources including intrinsic as well as extrinsic ganglia.

Noradrenergic and cholinergic innervation of the accessory sexual glands in male sheep

Immunohistochemistry was applied to determine the distribution patterns of nerve fibres containing tyrosine hydroxylase (TH), dopamine beta-hydroxylase (DbetaH), neuropeptide Y (NPY), vasoactive intestinal peptide (VIP) and vesicular acetylcholine transporter (VAChT) in the prostate, seminal vesicle (SV) and bulbourethral glands (BU) of male sheep. In all organs studied, cholinergic innervation was more developed than noradrenergic innervation. Numerous VAChT-immunoreactive (IR) nerve fibres were found in the muscular layer and mucosa of the SV and BU as well as in the prostate. A similar abundance of noradrenergic nerve fibres (showing immunoreactivity both to TH and DbetaH) was also found in both layers of the SV and BU (but not in the prostate). In the prostate a moderate density of VIP-IR nerve fibres was present but only very scarce NPY-IR nerve fibres were shown. All the studied accessory sexual glands (ASG) of male sheep contained VIP-IR nerve fibres in a similar frequency. Double immunohistochemistry revealed that the vast majority of noradrenergic nerve fibres also contained NPY. None of the noradrenergic nerve fibres showed the presence of VAChT or VIP. The possible functional significance of these findings is discussed.

Neurochemical properties of the middle cervical ganglion in the sheep

The neurochemical properties of the ovine middle cervical ganglion (MCG) were studied using antibodies raised against tyrosine hydroxylase (TH), dopamine beta-hydroxylase (DbetaH), neuropeptide Y (NPY), substance P (SP), calcitonin gene-related peptide (CGRP), vasoactive intestinal polypeptide (VIP) and galanin (GAL). Double-labelling immunocytochemistry revealed that the vast majority (95.5 +/- 0.8%) of postganglionic sympathetic MCG neurons expressed simultaneously both catecholamine-synthesizing enzymes (neurons were TH/DbetaH-positive). A large population of noradrenergic neurons exhibited immunoreactivity (IR) to NPY (62.2 +/- 2.2%), but single NPY-positive perikarya-lacking noradrenergic markers were also observed (2.0 +/- 0.3%). None of the examined MCG neuronal somata contained SP, CGRP, GAL or VIP. A moderate number of noradrenergic nerve fibres located amongst neuronal cell bodies was also found. In small number of these terminals the presence of NPYor GAL (but not CGRP or VIP) was detected. The ovine MCG was numerously innervated with SP-immunoreactive nerve fibres which sometimes formed basket-like formations around postganglionic neurons. The MCG exhibited a sparse CGRP-immunoreactive innervation and lacked VIP-positive nerve terminals. In many aspects the chemical coding of MCG postganglionic neurons and nerve terminals resembles that found in other mammalian cervico-thoracic paravertebral ganglia, but some important species-dependent differences exist. The functional implications of these differences remain to be elucidated.

Origin and Chemical Coding of Primary Afferent Neurones Supplying the Prostate of the Dog

Retrograde tracing technique combined with the double-fluorescent immunohistochemistry were used to investigate the distribution and chemical coding of primary afferent neurones supplying the canine prostate. After the injection of Fast Blue (FB) into the prostatic tissue retrogradely-labelled (FB(+)) primary afferent neurones were localized in bilateral L(1)-Ca(1) dorsal root ganglia (DRG). Statistical analysis using anova test showed that there are two major sources of afferent prostate innervation. The vast majority of prostate-supplying primary afferent neurones were located in bilateral L(2)-L(4) DRG (56.9 +/- 0.6%). The second source of the afferent innervation of canine prostate were bilateral S(1)-Ca(1) DRG (40.6 +/- 1.0%). No statistically significant differences were found between average number of FB(+) neurones localized in the left and right DRG (49.5 +/- 1.7 and 50.5 +/- 1.7%, respectively). Immunohistochemistry revealed that FB(+) primary afferent neurones contain several neuropeptides in various combinations. In the prostate-supplying neurones of lumbar and sacro-caudal DRG the immunoreactivity to substance P (SP) and calcitonin gene-related peptide (CGRP) was found most frequently (50 +/- 3.7 and 37.3 +/- 1.9%, respectively). Both in the lumbar and sacro-caudal DRG, considerable population of FB(+) neurones immunoreactive neither to SP nor CGRP were also found (23 +/- 2.6 and 32.8 +/- 2.3%, respectively). In the lumbar DRG 10.7 +/- 1.1% of SP-immunoreactive FB(+) neurones also contained galanin (GAL). In 9.2 +/- 2.2% of the prostate-supplying primary afferent neurones located in the sacro-caudal DRG the co-localization of SP and GAL was also reported. Results of the retrograde tracing experiment demonstrated for the first time sources of afferent innervation of the canine prostate. Double immunohistochemistry revealed that many of the prostate-supplying primary afferent neurones express some of sensory neuropeptides which presumably may be involved in nociception and some pathological processes like inflammation or nerve injury.

Origin of the primary efferent neurons projecting to the prostate of the dog

The retrograde tracing technique of neuronal tracer Fast Blue was used to determine sources of origin of efferent nerve fibers supplying the prostate of the dog. After injection of Fast Blue into the canine prostate retrogradely labelled neurons were found in bilateral L3-S3 sympathetic chain ganglia, bilateral caudal mesenteric ganglion and in bilateral pelvic plexus ganglia. No Fast Blue-positive neurons were present in bilateral L1-L2 sympathetic chain ganglia and in coeliac-mesenteric ganglion complex. The vast majority of Fast Blue-positive efferent prostate-projecting neurons (56.2% +/- 1.7) were located in bilateral caudal mesenteric ganglion, whereas 28.7% +/- 1.5 of them were located in bilateral pelvic plexus ganglia and 14.9% +/- 0.5 in bilateral L3-S3 sympathetic chain ganglia. Immunohistochemical staining for tyrosine hydroxylase and dopamine beta-hydroxylase was applied to determine the neurochemical character of Fast Blue-positive efferent neurons. Immunohistochemistry revealed that in all tyrosine hydroxylase immunoreactive Fast Blue-positive neurons immunoreactivity for dopamine beta-hydroxylase was also found (noradrenergic neurons) while all tyrosine hydroxylase-negative Fast Blue-positive neurons did not express dopamine beta-hydroxylase (non-noradrenergic neurons). In bilateral sympathetic chain ganglia, 96.4% +/- 2.1 of the prostate-projecting neurons were adrenergic and in bilateral caudal mesenteric ganglion this frequency amounted to 95.6% +/- 1.6. In bilateral pelvic plexus ganglia, 26.7% +/- 1.5 of the prostate-supplying efferent neurons did not express either tyrosine hydroxylase or dopamine beta-hydroxylase immunoreactivity which makes discussion of their cholinergic character possible.

Co-expression of tyrosine hydroxylase, dopamine beta-hydroxylase and neuropeptide Y in the sympathetic neurons projecting to the submandibular gland in the sheep

Sympathetic neurons projecting to the ovine submandibular gland (SMG) from the superior cervical ganglion (SCG) and middle cervical ganglion (MCG) were identified using retrograde tracing with fluorescent dye (Fast Blue). Antibodies to tyrosine hydroxylase (TH), dopamine beta-hydroxylase (DbetaH) and neuropeptide Y (NPY) were used to determine the immunochemical characteristics of SMG-innervating sympathetic neurons. Immunohistochemistry combined with the retrograde tracing revealed that the population of SMG-projecting neurons consist of four distinct sub-populations, but taking into account their possible different physiological properties only three major sub-populations can be distinguished. The vast majority of neurons in both ganglia are noradrenergic in nature (co-express TH and DbetaH). All examined TH-immunoreactive (IR) neurons also show immunoreactivity to DbetaH. Sub-population of noradrenergic neurons can be divided into NPY-IR and non-NPY-IR. Noradrenergic neurons expressing NPY may act as vasoconstrictors. The second sub-population of SMG projecting neurons in the ganglia studied consists of non-noradrenergic neurons (containing NPY, but not TH). It is known that these kinds of neurons may play a vasodilatory role. In both examined ganglia the third sub-population consists of non-TH-IR and non-NPY-IR neurons of unknown physiological function. Since no DbetaH immunoreactivity was found in any of TH- neurons these nerve cells can also be regarded as non-noradrenergic. It is possible that some neurons of the second as well as the third sub-population are cholinergic and some of them are non-noradrenergic/non-cholinergic in character.

Distribution of calcitonin gene-related peptide (CGRP), substance P (SP) and galanin (GAL) immunoreactive nerve fibers in the seminal vesicle and prostate of the male sheep

Double immunohistochemistry was used to determine the occurrence and distribution pattern of nerve fibres immunoreactive to calcitonin gene-related peptide (CGRP), substance P (SP) and galanin (GAL) in seminal vesicles and prostate of the male sheep. Numerous CGRP- and SP-immunoreactive (IR) nerve fibres were found in the mucosal layer and smooth musculature of the seminal vesicles and prostate. In both glands nerve terminals immunoreactive to CGRP were more numerous than SP-IR ones. The majority of CGRP-IR nerve fibers showed colocalization of this peptide and SP. In both layers of the seminal vesicle and prostate, rare nerve terminals immunoreactive to GAL were also found. Immunoreactivity to SP was also found in all GAL-IR nerve fibers. The presence of numerous CGRP- and SP-IR nerve fibers in the seminal vesicle and prostate of the male sheep suggests that these neuropeptides may be involved in the sensory transmission and/or control of smooth muscle contractility. On the other hand, a relatively low number of GAL-IR nerve fibers of the seminal vesicle and prostate suggest that this peptide may act as an anti-nociceptive agent. It cannot be excluded that, in the seminal vesicle, GAL may also be involved in the control of the smooth muscle fiber activity. The possible role of CGRP, SP and GAL in the regulation of functions of the accessory sexual glands needs to be determined in further physiological studies.

Distribution of sympathetic and afferent neurones innervating the submandibular gland in the sheep

The distribution of sympathetic and sensory neurones innervating the submandibular gland (SMG) in sheep was studied using retrograde tracing technique. The retrograde tracer Fast Blue (FB) was unilaterally injected into the SMG in five juvenile male sheep under general anaesthesia. After a 4-week survival period, all the animals were reanaesthetized, perfused transcardially with 4% buffered paraformaldehyde and ganglia, which could be considered as a potential sources of sympathetic, and afferent innervation of the gland were bilaterally collected. The FB-labelled sympathetic neurones were found in the ipsilateral superior and middle cervical ganglion. Many labelled neurones were distributed in the ipsilateral jugular and nodose ganglia of the vagus nerve and smaller numbers of the nerve cells were also found in ipsilateral C1-C3 dorsal root ganglia (DRG). No labelled neurones were observed in the ipsilateral stellate ganglion, trigeminal ganglion, C4-C8 DRG and in all contralateral ganglia. The present study revealed that the majority of sympathetic neurones projecting to the sheep SMG are found in the superior cervical ganglion but some of them are also distributed in the middle cervical ganglion. Most of the afferent neurones are located in the jugular and nodose ganglia of vagus nerve but C1-C3 DRG also comprise some of these nerve cells.