Somatotopic Representation within the Facial Motor Nucleus of the Chicken Studied by Means of Horseradish Peroxidase

The distribution in the chicken of motoneurons innervating the hyolingual muscles, i.e. the M. branchiomandibularis (BM), M. ceratoglossus (CG), M. interceratobranchialis (CB), M. serpihyoideus (PH), M. stylohyoideus (YH) and one of the mandibular muscles. M. depressor mandibulae (DM), was examined by retrograde transport of horseradish peroxidase conjugated with wheatgerm agglutinin. Labelled motoneurons are found in the three subnuclei of the facial (VII) nucleus, as well as hypoglossal (XII) nucleus. The distribution of motoneurons projecting to the DM are observed in the three subnuclei, those of the BM, PH and YH in the intermediate and ventral subnuclei and those of the CB and CG in the intermediate subnucleus. Motoneurons projecting to the PH, YH, CB and CG are also distributed in the XII nucleus. The ratio of labelled motoneurons of the VII to XII nuclei decreases the PH, YH, CB and CG in that order, and the ratio of labelled ones of the ventral to intermediate subnuclei decreases the BM, PH and YH in that order. The topographical and functional aspects of the subdivision of the motor nucleus are discussed.     

Origin, course and distribution of the hypoglossal nerve in the New Zealand rabbit (Oryctolagus cuniculus L)

With 8 figures SUMMARY: This study aimed at revealing the origin, course and distribution of the hypoglossal nerve in 20 adult male New Zealand rabbits. In all the animals dissected, the hypoglossal nerve arose from the ventrolateral side of the medulla oblongata with two main roots and gave off a descending branch to the ansa cervicalis before reaching the division of the common carotid artery. This branch was not seen on the right side of only one case. At the lateral aspect of the hyoglossus muscle, the nerve then divided into the lateral and medial main branches, sent branches to the styloglossus, hyoglossus, genioglossus and geniohyoideus muscles and terminated in the intrinsic tongue muscles. A communicating branch was observed between the hypoglossal and accessory nerves in the right side of one animal and between the hypoglossal nerve and the ganglion nodosum in the right retropharyngeal area of another animal. An additional branch was observed innervating the stylohyoideus muscle in one animal only. A lateral lingual-hypoglossal communication was also seen between the lateral branch of the hypoglossal nerve and terminal branches of the lingual nerve.     

Motor Neuron Organization and Corticospinal Fibers in the Cervical Intumescence of the Raccoon (Procyon lotor) Spinal Cord

Experiments were performed on 19 raccoons to determine the organization of the spinal alpha motoneurons innervating the muscles of the thoracic limb. Chromatolysis of motoneurons was provoked by resecting major nerves or removing individual muscles or muscle groups. Proximal intrinsic limb muscle motoneurons were located cranially in the cervical spinal intumescence and distal muscle motoneurons more caudally. Flexor motoneurons were generally dorsal and more laterally located within the lateral motoneuronal cell group than were the cell bodies innervating their extensor antagonists. The distribution of motor cortex projections to motoneurons was studied in five raccoons by selective silver impregnation of degenerating fibers after unilateral motor cortex ablation. Degenerating cortical projections within the motoneuronal cell group (Rexed's lamina IX) were seen only in the more dorsal and the lateral portions in the seventh and eighth cervical and the first thoracic spinal cord segments. Motor cortex preterminal and terminal fibers were in close apposition to the proximal dendrites and the somata of alpha motoneurons innervating primarily the more distal limb musculature and particularly the intrinsic muscles of the manus.     

Localization of the motoneurons innervating the hindlimb muscles in the spinal cord of the domestic fowl

The origins of the motor nerve fibers supplying the individual hindlimb muscles were elucidated in the fowl by the retrograde degeneration method. Chromatolytic cells were seen in the ipsilateral lamina 9 of the lumbosacral enlargement. Motoneurons innervating the individual hindlimb muscles were localized in the characteristic position of lamina 9. Both hip and thigh muscles are supplied by motoneurons of almost all the columns in lumbar segments and by those of dorsolateral columns in sacral segments, while the shank and foot muscles are supplied by motoneurons of ventromedial columns in sacral segments. The origins of the dorsal cord of the lumbosacral plexus are situated laterally in the lamina 9 and those of the ventral cord are located medially in it.     

Genome-wide DNA methylation profiles in Tibetan and Yorkshire pigs under highaltitude hypoxia

Background: Tibetan pigs, which inhabit the Tibetan Plateau, exhibit distinct phenotypic and physiological characteristics from those of lowland pigs and have adapted well to the extreme conditions at high altitude.However, the genetic and epigenetic mechanisms of hypoxic adaptation in animals remain unclear.Methods: Whole-genome DNA methylation data were generated for heart tissues of Tibetan pigs grown in the highland(TH, n = 4) and lowland(TL, n = 4), as well as Yorkshire pigs grown in the highland(YH, n = 4) and lowland(YL, n = 4), using methylated DNA immunoprecipitation sequencing.Results: We obtained 480 million reads and detected 280679, 287224, 259066, and 332078 methylation enrichment peaks in TH, YH, TL, and YL, respectively. Pairwise TH vs. YH, TL vs. YL, TH vs. TL, and YH vs. YL comparisons revealed6829, 11997, 2828, and 1286 differentially methylated regions(DMRs), respectively. These DMRs contained 384, 619,192, and 92 differentially methylated genes(DMGs), respectively. DMGs that were enriched in the hypoxia-inducible factor 1 signaling pathway and pathways involved in cancer and hypoxia-related processes were considered to be important candidate genes for high-altitude adaptation in Tibetan pigs.Conclusions: This study elucidates the molecular and epigenetic mechanisms involved in hypoxic adaptation in pigs and may help further understand human hypoxia-related diseases.     

Immunohistochemical Characterization of Neurones in the Hypoglossal Nucleus of the Pig

With 4 figures and 1 table In this study, the presence of several neurotransmitters and transmitter synthesizing enzymes was studied in hypoglossal nucleus (HN) of the juvenile (4 months old) female pigs (n = 3). Double‐labeling immunofluorescence revealed neurones expressing cholinacetyltranspherase (ChAT), calcitonin gene‐related peptide (CGRP), nitric oxide synthase (NOS), and somatostatin (SOM). Nerve fibers within HN were ChAT, CGRP, NOS, SOM, substance P (SP), Leu‐5‐enkephalin (Leu‐5‐Enk), ß‐dopamine hydroxylase (DßH), neuropeptide Y (NPY) positive. Virtually all the perikarya contained ChAT, whereas CGRP was present in 47% of the neurones. Nerve cell bodies containing NOS or SOM were only occasionally observed. Immunoreactive nerve fibers were found in a close vicinity of the perikarya, often forming baskets around nerve cell bodies. The results obtained were compared with similar data obtained in other species. The presence of immunoreactive structures, origin of the nerve fibers, and functional significance of the findings are discussed.     

Localization of the Motoneurons Innervating the Forlimb Muscles in the Spinal Cord of the Domestic Fowl

The origins of the motor nerve fibers supplying the individual forelimb muscles were elucidated in the fowl by the retrograde degeneration method. Chromatolytic cells were seen in the ipsilateral lamina 9 of the cervical enlargement. Motoneurons innervating the individual forelimb muscles occupy the restricted area in the lamina 9. The muscles acting on the shoulder joint are supplied by motoneurons of the more cranial segments and the others acting on the elbow and the more distal joints by those of the more caudal ones. The origin of the dorsal cord is situated laterally in the lamina 9 and that of the ventral cord is located medially in it.     

Age-related three-dimensional morphological changes in rat motoneurons innervating diaphragm and longissimus muscles

We investigated age-related morphological changes of rat motoneurons innervating diaphragm muscle (DI-MN) and lumber longissimus muscle (LL-MN) in which quite different activation patterns exist. In young (2-4 months) and old (24-26 months) rats, the motoneurons innervating both muscles were labelled retrogradely by intramuscular injection of cholera toxin B subunit. After a 4-day survival, horizontal slices of the spinal cord were processed with immunohistochemical staining (first antibody to cholera toxin B subunit and second antibody with Cy3) and observed with a confocal microscope. Three-dimensional reconstruction of labelled motoneurons was performed to examine soma and dendrite morphology. As compared to the soma volume in young rats, significantly smaller values were found in old rats in both motoneurons and the degrees of decline were 16.1% in DI-MN and 20.3% in LL-MN. Significant decreases in the thickness of primary dendrites were also found in both motoneurons, and the degrees of decline were 17.5% in DI-MN and 22.3% in LL-MN. Smaller changes were found in DI-MN than in LL-MN, indicating the possibility that increased activation by central drives can attenuate age-related morphological changes of the motor system in the spinal cord.     

Immunohistochemical properties of motoneurons supplying the trapezius muscle in the rat

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

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.     

Skeletal muscle protein synthesis and growth hormone secretion in young lambs treated with clenbuterol

To determine effects of clenbuterol (CB) on muscle protein turnover and growth hormone (GH) secretion, 16 crossbred wether lambs (14.4 kg) were randomized into two groups designated to receive daily oral boluses of gelatin capsules containing corn starch with either 0 (control, CTL) or 1.87 mg/kg body weight CB for either 14 (n = 8) or 28 d (n = 8). This calculates to be approximately 40 mg CB/kg diet. Lambs had ad libitum access to a 16% crude protein corn-soy diet and feed consumption (FC) was measured. After 14 and 28 d, lambs were slaughtered and semitendinosus (ST), longissimus (LD) and brachialis (BR) muscles were exercised, weighed and analyzed for protein (TP) content. For 6 h prior to slaughter of 28-d lambs, 2.5 microCi L-[U-14C]tyrosine/kg was infused intravenously, blood was sampled and plasma was analyzed for specific radioactivity of tyrosine. Plasma GH concentrations were assessed by radioimmunoassay. No differences due to treatment were found in FC, rate of gain or GH concentrations. Semitendinosus and BR weights of control lambs at 14 d did not differ between treatments. At 28 d, ST and BR weights of control lambs (58.8 and 18.5 g, respectively) were less (P less than .10) than those of lambs treated with CB (74.3 and 23.1 g, respectively). The TP per ST and BR at 28 d for control lambs was 71.5 and 85.1% (P less than .10) that of muscles of lambs treated with CB. Fractional protein synthesis rates (FSR) of the BR (9.4 vs 6.1%/d) and total protein synthesized in ST muscle per day (1.4 vs .8 g) were elevated (P less than .10) in lambs treated with CB compared to controls. These data suggest that the increased fractional accretion rate observed in lambs treated with CB for 28 d was caused by increased FSR.     

Mapping of Neurotensin in the Alpaca (Lama pacos) Brainstem

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

冻融对早胜牛肉品质及微细结构的影响

为探讨反复冻融对早胜牛肉品质的影响,选取2.0～2.5岁阉割牛背最长肌,随机分成6组,称重,真空包装,进行不同次数的反复冷冻—解冻试验,分别检测原料肉解冻损失、煮制损失、失水率、熟肉剪切力及pH,并观察原料肉显微超微结构的变化。结果显示,随着反复冻融次数的增加,原料肉解冻损失和煮制损失极显著增加,失水率只在第1次冻融后显著增加,剪切力先显著增加后再降低,pH随着冻融次数增加而显著降低,肌纤维结构混乱,肌束及肌原纤维间隙增加,肌节略微缩短,线粒体肿胀、空泡样变,Z线错位排列,甚至溶解、消失。结果表明,反复冻融严重破坏了早胜牛肉的组织结构,显著降低了肉品质。     

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

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

Expression of relaxin receptor LRG7, canine relaxin, and relaxin-like factor in the pelvic diaphragm musculature of dogs with and without perineal hernia

OBJECTIVES: To compare the expression of canine relaxin, relaxin-like factor (RLF), and relaxin receptors within the muscles of the pelvic diaphragm of dogs with perineal hernia (PH) and clinically normal dogs. STUDY DESIGN: In vivo comparative study. ANIMALS: Fifteen client-owned intact male dogs with PH were studied. Four mature intact male dogs with no evidence of perineal pathology served as controls. METHODS: Biopsy samples from the levator ani, coccygeus, and internal obturator muscles were obtained. RNA samples were reverse transcribed and analyzed by real-time PCR for the expression of canine relaxin receptor LRG7, relaxin, and RLF. RESULTS: Significantly higher expression levels of canine relaxin receptors occurred in the musculature of the pelvic diaphragm and internal obturator muscle in dogs with PH compared with normal dogs. Expression of canine RLF revealed no significant difference between dogs with PH and controls. The difference in the expression of canine relaxin between groups was not statistically significant. CONCLUSIONS: Relaxin receptor up-regulation occurs in the coccygeus, levator ani, and internal obturator muscles of dogs with PH. CLINICAL RELEVANCE: The higher expression of relaxin receptors within the muscles of the pelvic diaphragm in dogs with PH suggests that relaxin might play a role in the pathogenesis of PH. Atrophy of these muscles, which predisposes to PH, may be attributable to increased relaxin activity.     

Distribution and cytoarchitecture of sympathetic neurons innervating the pineal gland in chick: a CTB-HRP study

The neurons in bilateral superior cervical ganglia (SCG) innervating the chick pineal gland were labelled by using the technique of retrograde axonal labelling with cholera toxin B subunit linked to horseradish peroxidase (CTB-HRP). To our results, perikarya of these sympathetic neurons distributed from rostral to caudal in the SCG, and mainly localized in the opposite side of the paravertebral trunk. The fibres of these neurons were collected by the cephalic carotid nerve. According to the sizes of somal area and dendritic field, these sympathetic neurons projecting to the pineal gland were classified into four major groups: group I cells (52.4%) with a small somal area (303.5 μm² on average) and narrow dendritic field (3767.8 μm² on average), group II cells (39.0%) with a middle-sized somal area (473.3 μm²) and middle-sized dendritic field (7522.2 μm²), group III cells (6.4%) with a middle-sized somal area (473.4 μm²) and wide dendritic field (13 104.4 μm²), and group IV cells (2.2%) with a large somal area (940.7 μm²) and wide dendritic field (14 553.2 μm²). Of these pineal projecting neurons, most took on a lesser dendritic field. The neurons with small or middle-sized dendritic field from group I and II were about 91.4% of the total neurons labelled with CTB-HRP, and the neurons with wide dendritic field from group III and IV were less with 8.6%.     

BQ123抑制低温诱发肺动脉高压肉鸡的肺小动脉肌型化

本试验用高选择性内皮素A受体拮抗剂BQ123处理低温肉鸡的方法,通过动态观察肺动脉压及肌型、部分肌型及非肌型肺小动脉数量的变化,探讨内源性内皮素在肺血管重塑中的作用。结果显示:30日龄时,低温组平均肺动脉压极显著高于常温组、低BQ123组及高BQ123组(P<0.01);低温组肌型及部分肌型肺小动脉的占位比均极显著高于常温组、低BQ123组及高BQ123组(P<0.01);低温组非肌型肺小动脉占位比极显著低于常温组、低BQ123组和高BQ123组(P<0.01),高BQ123组显著高于低BQ123组(P<0.05)。结果表明,BQ123可明显抑制低温肉鸡肺动脉高压和非肌型肺小动脉的肌型化的发生发展,因此认为内源性ET在低温诱发肺动脉高压肉鸡肺血管重塑的发生发展过程中起重要作用。     

Sex Differences in the Number and Size of Motoneurons Innervating Rat Medial Gastrocnemius Muscle

The sex differences in the number and morphometric parameters of motoneurons in motor nuclei are poorly known. The aim of this study was to determine the differences in the number and size of alpha and gamma motoneurons of the medial gastrocnemius (MG) muscle in male and female Wistar rats. Retrogradely labelled cell bodies of motoneurons of 6 months old animals were studied following a bath of the proximal stump of the transected MG nerve in a horseradish peroxidase solution. The number and soma diameters of male and female MG motoneurons were determined from serial microscopic images of sections. The weight of the brain and spinal cord was on average 17% higher in males than in females. The mean number of motoneurons was 13% higher in males than in females and amounted to 94 and 83 motoneurons, respectively. In each case, the average soma diameters and cross‐section areas of motoneurons in motor nucleus were distributed bimodally: motoneurons smaller than 27.5 μm in diameter were recognized as gamma and greater ones as alpha motoneurons. In males, the motor nucleus contained on the average 66 alpha motoneurons, whereas in females, 56 alpha motoneurons, that is the mean number of alpha motoneurons was 17% higher in males. Moreover, the soma diameters of gamma and alpha motoneurons were significantly bigger in males and the difference amounted 9 and 6%, respectively. It is concluded that the number as well as size of alpha and size of gamma motoneurons in the MG motor nucleus are greater in males.     

Distribution of Galanin and Galanin Receptor 2 in the Pre‐optic Area of the Female Guinea Pig

This study describes the distribution of galanin (Gal) and galanin receptor 2 (GalR2) in the pre‐optic area (POA) of the female guinea pig. Frozen sections were undergone for a routine immunofluorescence labelling. Gal and GalR2 display immunoreactivity in all parts of the pre‐optic area. Gal shows reactivity both in perikarya and fibres, whereas GalR2 was observed only in perikarya. Gal‐ and GalR2‐immunoreactive (‐ir) perikarya were the most numerous in the medial pre‐optic area (MPA) with the highest reactivity in its dorsal part. In the median pre‐optic nucleus (MPN) and periventricular pre‐optic nucleus (PPN), only single Gal‐ and GalR2‐ir neurons were observed. The highest density of Gal‐ir fibres was revealed in the PPN and the lowest in the lateral pre‐optic area (LPA). The results of this study indicate that the distribution pattern of Gal containing neurons overlaps well with the distribution pattern of GalR2‐positive neurons, especially in the MPA. This may suggest GalR2‐dependent activity in this brain region.