Estrogen receptor alpha expression in the medial preoptic area and the medial basal hypothalamus under different physiological conditions in cattle

The distribution and morphology of immunoreactive estrogen receptor alpha (ERalpha)- containing cells were examined in the cattle brain. The brains were collected from two cows and a male calf. One of the cows was sacrificed one week after parturition. ERalpha expressions in the preoptic area of the rostral forebrain and the medial basal hypothalamic area were evaluated immunohistochemically using a mouse monoclonal antibody. In all animals, the signals that indicate ERalpha were detected in the medial preoptic area, the level of the organum vasculosum of the lamina terminalis and the bed nucleus of the stria terminalis. In the caudal hypothalamic region, they were detected in the arcuate nucleus, the periventricular and ventromedial hypothalamic nuclei. ERalpha-containing cells were characterized by a dense nuclear reaction product. In all the subjects examined, ERalpha signals were clearly detected in the cytoplasm as well. The density of ERalpha expression was different among the three cattle; the number of ERalpha containing cells in the postpartum cow was much lower than that in the other cow and the male calf. The present findings suggest that ERalpha expression in the forebrain is influenced by the reproductive status in the cattle.     

Immunolocalization of Aquaporins 1 and 9 in the Ram Efferent Ducts and Epididymis

Aquaporins (AQPs) are essential membrane protein channels for the transport of water across membranes. Fluid movement in the epididymis is important for modulation of the luminal environment, in which sperm mature and reside. This study was designed to understand the morphology and localization of AQPs in ram efferent ducts (ED) and epididymis. For this purpose, the epididymis of seven animals were removed for histologic and immunohistochemical analyses. AQP1 immunoreactivity was observed in the apex of the ED, and AQP9 was found adjacent to the nuclei of the epithelial cells of the ED. The epithelial lining of ram epididymis is pseudostratified columnar and presents principal, basal, apical and narrow cells. In the initial segment (IS), a moderate reaction for AQP1 was observed in the apical cytoplasm of epithelial cells. An intense reactivity for AQP1 was noted over the microvilli of principal cells and in spermatozoa in the caput. In the corpus and cauda, AQP1 was noted only over the endothelial cells of vascular channels located in intertubular spaces. A weak‐to‐moderate reaction for AQP9 was observed in the nuclei of epithelial cells in the IS, caput and corpus of the epididymis. In the cauda, an intense reaction to AQP9 was observed in the epithelial border. In the IS, caput and corpus, the reactivity for AQP9 differed from those observed in domestic animals. The cauda showed a pattern similar to that previously described. These results indicate that AQPs 1 and 9 have reversed locations and roles in rams, suggesting activity variations related with fluid and solute absorption throughout the epididymis.     

Human embryonic stem cells: possibilities for future cell transplantation therapy

Human embryonic stem cells are of great importance, and Parkinson's disease is given as an example of a condition that could benefit from the development of stem cell-based transplantation therapies. The reason for this is fairly obvious: the disease is caused by the loss of only one cell type from the brain that has one major function, namely the production of dopamine. Replacement of these cells should in principle cure the disease. But what are stem cells and how far is scientific research from being able to offer stem cell-based therapy in the clinic to patients suffering from Parkinson's disease, and other chronic diseases? These questions are addressed here together with a critical evaluation of short and long-term clinical perspectives, and a discussion of possible alternatives such as adult stem cells.     

A technique for the description of projections of internal organs onto the exposed surface of animals.

The need for exact knowledge of the projections of internal organs onto the surface of animals is emphasized, for clinical veterinary medicine as well as for hunting purposes. A method is described for outlining the projections of dissected anatomical structures onto the exposed surface, on a photograph of the undisturbed animal in a natural standing position.     

Ultrastructure of the Integument of the Domestic Pig (Sus scroh) from One through Fourteen Weeks of Age

The biopsies of normal lumbar and dorsal thoracic pig epidermis and dermis are described ultrastructurally at one, three, five, seven, nine and fourteen weeks and compared to the human integument. In the epidermis, basal cell projections extended into the dermis and increased slightly with age. Intraepidermal axons were seen. The basal lamina thickened opposite the hemidesmosomes of the epidermal-dermal junction. Small anchoring fibrils extended from the basal lamina into the dermis. Mitochondria were concentrated beneath the cellular nuclei of the stratum basale. Upper stratum spinosum and stratum granulosum cells contained membrane coating granules. The stratum corneum contained cells of varying density. The only intraepidermal nonkeratinocytes observed were melanocytes and Langerhans-like cells. Both were similar to those of humans. In the dermis, the interfollicular muscle resembled the arrector pili and smooth muscle found in other body areas. Nerve fibers were similar to those described in humans except subepidermal nerve endings contained mitochondria. One unexpected finding was the presence of mast cells which were enveloped by a zone of loose floccular material which stained positive with PAS from seven through fourteen weeks of age. Mast cell population density peaked at seven weeks and was greater in the papillary dermis than in the reticular dermis. Generally, the pig integument is morphologically similar to that of man and would serve as a useful animal model when age changes are accounted for.     

Disparities in activity levels and learning ability between Djungarian hamster (Phodopus sungorus) and Roborovskii hamster (Phodopus roborovskii)

The Djungarian hamster and the Roborovskii hamster belong to the same genus of Phodopus. However, the Djungarian hamster is tame and shows sedative behavior, while Roborovskii hamster is not tame and shows high levels of locomotor activity. Hyperactivity occurs in animals with tameless behavior. Tameness or tamelessness behavior is very important because tameness helps for breeding and controlling as well as it enables a strong human‐animal bond. In the present study, we examined the relationships between activity levels and cognitive function in Djungarian and Roborovskii hamsters. Three types of behavioral tests were performed to analyze their activity levels, memory and leaning ability. The levels of L‐ and D‐amino acids and monoamines in the brain were then determined. Roborovskii hamsters showed significantly higher locomotor activity than Djungarian hamsters. Memory ability was not significantly different between the two hamsters, but Roborovskii hamsters showed lower learning ability. Brain levels of D‐serine which is related to enhancement in memory and learning ability, were significantly higher in Djungarian hamsters, but the reverse was true for brain dopamine and serotonin levels. These results suggest that these differences in brain metabolism may be related to the behavioral differences between the two hamsters.     

Hormonal responses to acute exercise, training and overtraining. A review with emphasis on the horse

Overtraining is an imbalance between training and recovery leading to symptoms associated with a neuroendocrine dysbalance called the overtraining syndrome, a disease characterized by behavioral, emotional and physical symptoms similar with depression. Although the prevalence of overtraining is high in human and equine athletes, at present no sensitive and specific test is available to prevent or diagnose overtraining. Nowadays, it is believed that combination of different (hormonal) parameters appear to be the best indicators of overtraining. Therefore, this review provides a summary of previous literature examining the response of the hypothalamic-pituitary-adrenal (HPA) axis and the growth hormone-insulin-like growth factor-I (GH-IGF-I) axis to acute and chronic exercise as well as overtraining in humans and horses. The exercise induced hormonal responses seem to be equal for the equine as well as the human athlete, which makes comparisons possible. Repeated bouts of exercise are suggested to provide a way to detect subtle changes in hormonal responses in the individual athlete, which may make them an important tool in detecting early overtraining. This should be combined with corticotropin releasing hormone (CRH) stimulation tests and basal ACTH and GH pulsatility determination. Further research is needed to establish the correct training intensity and rest period for the exercise test in equines.     

Neurogenesis in Neurotoxin-induced Animal Models for Parkinson's Disease-A Review of the Current Status

Animal models for Parkinson's disease (PD) are essential for understanding its pathogenesis and for development and testing of new therapies. Discoveries of endogenous neurogenesis in the adult mammalian brain give new insight into the cell-based approach for treatment of neurodegenerative disorders, such as PD. Although a great deal of interest has been focused on endogenous neurogenesis in neurotoxin-induced animal models for PD, it still remains controversial whether neural stem cells migrate into the injured area and contribute to repopulation of depleted dopaminergic neurons in neurotoxin-injured adult brains. The purpose of this review is to examine the data available regarding neurogenesis in neurotoxin-induced animal models of PD. It is hoped that data from the animal investigations available in the literature will promote understanding of the neurotoxin-induced animal models for PD.     

FAMILIAL CEREBELLAR ATAXIA WITH HYDROCEPHALUS IN BULL MASTIFFS

Familial cerebellar ataxia with concurrent hydrocephalus has previously been described in a family of bull mastiff pups, and recently has been identified in a litter from Louisiana. The 4 affected pups had ataxia, hypermetria, conscious proprioceptive deficits, behavioral abnormalities, and a visual deficit. In magnetic resonance imaging of the brain of two of the pups, there were symmetric hydrocephalus and two focal areas of increased signal intensity within the central nuclei of the cerebellum. Histopathologically there was vacuolization and mild astrogliosis within the deep cerebellar nuclei (dentate, interpositus, fastigial), caudal colliculi, and lateral vestibular nuclei. Although the postmortem results were not exactly the same as in the previously published report, the clinical features and histopathologic findings strongly support the diagnosis. This disorder is most likely inherited in an autosomal recessive manner.     

Stereotaxic approach to hypothalamic nuclei of the Shiba goat with radiographic monitoring

Practical method was devised for precise approach to hypothalamic nuclei in the Shiba goat. A stereotaxic instrument and a brain atlas with stereotaxic coordinates were developed. For an accurate placement of probes into specific hypothalamic regions a radiographic method was employed in which radio-opaque material was injected into the lateral ventricle and the ventricular outline was depicted. A sagittal diagram showing the arrangement of hypothalamic nuclei in relation to the brain ventricular system was constructed from the transverse stereotaxic atlas. This diagram was revealed extremely useful in pinpointing the target on the radiographs of lateral view. Precision of this method was evaluated in female Shiba goats (n = 4) by comparing radiographically estimated positions of hypothalamic nuclei with those histologically determined. Despite of cranial variability among individual animals these two parameters matched well each other in all the nuclei examined. Furthermore, chronic cannulae were implanted into different hypothalamic structures of one goat and the accuracy of their placement was confirmed histologically. Thus, it was revealed that the stereotaxy by aid of radiography herein described was accurate enough to apply to various neuroendocrinological studies in the Shiba goat.     

Molecular genetics of the adrenocortical axis and breeding for robustness

The concept of robustness refers to the combination of a high production potential and a low sensitivity to environmental perturbations. The importance of robustness-related traits in breeding objectives is progressively increasing toward the production of animals with a high production level in a wide range of climatic conditions and production systems, together with a high level of animal welfare. Current strategies to increase robustness include selection for "functional traits," such as skeletal and cardiovascular integrity, disease resistance, and mortality at various stages. It is also possible to use global evaluation of sensitivity to the environment (eg reaction norm analysis or canalization), but these techniques are difficult to implement in practice. The glucocorticoid hormones released by the adrenal cortex exert a wide range of effects on metabolism, the cardiovascular system, inflammatory processes, and brain function, for example. Protein catabolism toward energy production and storage (lipids and glycogen) supports their pivotal role in stress responses aiming at the adaptation and survival of individuals under strong environmental pressure. Large individual variations have been described in adrenocortical axis activity, with important physiopathological consequences. In terms of animal production, higher cortisol levels have negative effects on growth rate and feed efficiency and increase the fat:lean ratio of carcasses. On the contrary, cortisol has positive effects on functional traits and adaptation. Intense selection for lean tissue growth and more generally high protein output during the past decades has concomitantly reduced cortisol production, which may be responsible for the negative effects of selection on functional traits. In this paper, we review experimental evidence suggesting that the balance between production and functional traits was modified in favor of improved robustness by selecting animals with higher adrenocortical axis activity, as well as the molecular genetic tools that can be used to fine-tune this objective.     

Allele frequency distribution of the canine dopamine receptor D4 gene exon III and I in 23 breeds

Various canine breeds are remarkably different from each other not only in their sizes and shapes but also in behavioral traits, suggesting that some of them are under genetic control. Although dopaminergic neurotransmission system is considered to affect animal behavior, little is known about related genes in canine. Relations between specific alleles in polymorphic regions of the dopamine receptor D4 gene (DRD4) and personality or psychiatric disorders have been reported in humans, and we first found polymorphism in exon III region of the gene in 4 canine breeds. In this study we surveyed allele frequency distribution in 23 breeds including a total of 1,535 unrelated individuals. In exon III, 8 alleles including a novel allele were identified. A group of breeds in which the alleles 447b, 498 and 549 were frequent tended toward high scores in aggression-related behavioral traits than that with frequent alleles 435 and 447a. Moreover, a polymorphism based on 24 bp insertion/deletion was found in exon I region for the first time in dogs. This information may be of use for candidate gene studies of behavioral variation in dogs.     

Effects of Melatonin on Gastrointestinal Tract Physiological Function of Ruminant北大核心CSCD

褪黑素(MT)是调节胃肠道运动、免疫功能及微生物菌群结构等的胺类激素,其前体物质(色氨酸)是微生物群-肠-脑轴的信号递质。目前有关MT的研究多集中于单胃动物,鲜见MT对反刍动物的综述报道。因此,本综述将从MT对反刍动物胃肠运动、摄食行为、生产性能以及胃肠道微生物的作用机制进行阐述,以期为MT作为反刍动物治疗辅助剂、饲料添加剂的价值提供参考。     

Kisspeptin as a master player in the central control of reproduction in mammals: An overview of kisspeptin research in domestic animals

The hypothalamo‐pituitary‐gonadal (HPG) axis is the regulatory system for reproduction in mammals. Because secretion of gonadotropin‐releasing hormone (GnRH) into the portal vessels is the final step at which the brain controls gonadal activities, the GnRH neuronal system had been thought to be central to the HPG axis. A newly discovered neural peptide, kisspeptin, has opened a new era in reproductive neuroendocrinology. As shown in a variety of mammals, kisspeptin is a potent endogenous secretagogue of GnRH, and the kisspeptin neuronal system governs both the pulsatile GnRH secretion that drives folliculogenesis, spermatogenesis and steroidogenesis, and the GnRH surge that triggers ovulation in females. The kisspeptin neuronal system is therefore considered a master player in the central control of mammalian reproduction, and kisspeptin and related substances could therefore be valuable for the development of novel strategies for the management of fertility in farm animals. To this end, the present review aimed to summarize the current research on kisspeptin signaling with a focus on domestic animals such as sheep, goats, cattle, pigs and horses.     

Regional brain monoamine concentrations and their alterations in bovine hypomagnesaemic tetany experimentally induced by a magnesium-deficient diet

Monoamines are important brain neurotransmitters. An investigation was carried out to determine if hypomagnesaemic tetany was associated with alterations in regional brain monoamine concentrations in bovines. The results, established in cows with normal magnesium status, demonstrated that regional differences existed in the distribution and concentration of brain monoamines in the adult bovine, which were similar to those in other species. In magnesium-deficient cows, severe hypomagnesaemia and lowered cerebrospinal fluid (CSF) magnesium concentrations were associated with significant alterations in monoamine concentrations in some brain regions. Alterations in 3,4-dihydroxyphenylalanine (DOPA) and dihydroxyphenylacetic acid (DOPAC) concentrations in the corpus striatum, and dopamine (DA) in the cerebral cortex and cerebellum were recorded. These regions play an important role in both voluntary and involuntary motor function, and therefore these alterations may play a role in the aetiology of hypomagnesaemic tetany. However, there was no significant change in DA concentrations in the corpus striatum (the main dopaminergic region in the brain) associated with hypomagnesaemia. In addition, a significantly lower norepinephrine (NE) concentration in the corpus striatum of hypomagnesaemic animals was also recorded. Norephinephrine is generally excitatory and therefore lowered NE concentrations would be expected to result in depression rather than stimulation of motor function.     

Ergocryptine and other ergot alkaloids stimulate the release of [3H]dopamine from rat striatal synaptosomes.

Ergocryptine is an ergot alkaloid that affects dopaminergic activity principally by interacting with D2-type receptors. In this study the ability of ergocryptine and several other ergot alkaloids to release [3H]dopamine from isolated nerve endings was demonstrated using in vitro superfusion of rat striatal synaptosomes. Ergocryptine, ergocristine, and bromocryptine produced an elevation in baseline dopamine release of approximately 400% with effective concentrations (EC50) of approximately 30 microM. Ergotamine, ergonovine, ergovaline, and ergocornine were devoid of activity. The time-course of the ergocryptine-stimulated release was relatively slow compared with amphetamine, nicotine, or K+-stimulated [3H]dopamine release; the maximal increase in release required a 5-min treatment. A number of receptor antagonists were examined for their ability to block ergocryptine-stimulated release. Of the dopaminergic, adrenergic, serotonergic, GABA-ergic, and cholinergic antagonists examined, only phentolamine produced a moderate attenuation in evoked release. Omission of Ca++ from the medium did not affect ergocryptine-evoked release. Following ergocryptine treatment, the synaptosomes were fully responsive to other stimulant. The results indicate that, in addition to interacting with dopamine receptors, several ergot alkaloids may produce dopaminergic effects by increasing the release of dopamine from central nerve endings. Several mechanisms to account for the evoked neurotransmitter release are discussed.     

Two cases of disseminated toxoplasmosis

Two cases of disseminated fatal toxoplasmosis of a pet mouse and a red panda are described. The pet mouse had a private owner; the red panda lived in a zoological garden in Saxony. At necropsy, both animals suffered from a systemic toxoplasmosis. A severe necrotizing hepatitis was the main histological feature in both animals. Parasitic cysts could be abundantly found in the liver, moderately in the brain and in a low number in other organs. With the PAS-reaction, cysts showed a weak staining in the mouse and a strong staining in the red panda. Diagnosis was confirmed by PCR and immunohistochemistry.     

The effect of acute restraint stress on regional brain neurotransmitter levels in stress-susceptible pietrain pigs

Concentrations of noradrenaline (NA), adrenaline (A), dopamine (DA), 5-hydroxytryptamine (5-HT), the DA metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) and the main 5-HT metabolite 5-hydroxyindole-3-acetic acid (5-HIAA) were measured using HPLC in 16 brain areas of control and immobilized Pietrain pigs. The animals were immobilized for 15, 30 and 60 min in the prone position. Control pigs showed patterns of regional distribution of brain monoamines similar to those described for rats, dogs and Duroc pigs. However, the absolute values of NA and A in the hypothalamus and preoptic area were much higher than those in rats and dogs, but similar to those in Duroc pigs. The concentrations of dopamine and its metabolites DOPAC and HVA were highest in the caudate nucleus, the nucleus accumbens, the olfactory tubercle and the ventral tegmental area. The distributions of serotonin and its metabolite 5-HIAA were similar in all examined structures. DOPAC/DA and HVA/DA ratios were higher in the cornu ammonis, the hippocampus posterior and the raphe nuclei than in other structures, which suggests brain structure-related differences in dopamine turnover. The greatest decreases in NA and A content were observed in the hypothalamus, the preoptic area and the olfactory tuberculum during the first 30 min of immobilization stress. 5-HT turnover was increased in the raphe nuclei, while DA turnover was affected in the raphe nuclei, the septum, the substantia nigra and the olfactory tubercle. We suggest that acute immobilization stress caused differences in regional patterns of brain biogenic amines, thereby maintaining adequate transmitter levels during stress in stress-susceptible pigs.     

PSITTACINE SKULL RADIOGRAPHY

The psittacine skull is a complex anatomic structure, frequently traumatized but difficult to adequately image with standard radiographic procedures. Multiple views including a ventrodorsal, a lateral, and complementary oblique projections are necessary to fully evaluate potential skull fractures in the avian patient. Magnification radiography is a relatively easy procedure that aids the review of small osseous structures. Familiarity with psittacine skull anatomy greatly facilitates radiographic interpretation of cranial trauma.