1
|
Ni R, Shu Y, Luo P, Zhou J. Sexual dimorphism in the bed nucleus of the stria terminalis, medial preoptic area and suprachiasmatic nucleus in male and female tree shrews. J Anat 2022; 240:528-540. [PMID: 34642936 PMCID: PMC8819044 DOI: 10.1111/joa.13568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 10/01/2021] [Accepted: 10/04/2021] [Indexed: 02/05/2023] Open
Abstract
Sex differences in behaviour partly arise from the sexual dimorphism of brain anatomy between males and females. However, the sexual dimorphism of the tree shrew brain is unclear. In the present study, we examined the detailed distribution of vasoactive intestinal polypeptide-immunoreactive (VIP-ir) neurons and fibres in the suprachiasmatic nucleus (SCN) and VIP-ir fibres in the bed nucleus of the stria terminalis (BST) of male and female tree shrews. The overall volume of the SCN in male tree shrews was comparable with that in females. However, males showed a significantly higher density of VIP-ir cells and fibres in the SCN than females. The shape of the VIP-stained area in coronal sections was arched, elongated or oval in the lateral division (STL) and the anterior part of the medial division (STMA) of the BST and oval or round in the posterior part of the medial division of the BST (STMP). The volume of the VIP-stained BST in male tree shrews was similar to that in females. The overall distribution of VIP-ir fibres was similar between the sexes throughout the BST except within the STMA, where darkly stained fibres were observed in males, whereas lightly stained fibres were observed in females. Furthermore, male tree shrews showed a significantly higher intensity of Nissl staining in the medial preoptic area (MPA) and the ventral part of the medial division of the BST than females. These findings are the first to reveal sexual dimorphism in the SCN, BST and MPA of the tree shrew brain, providing neuroanatomical evidence of sexual dimorphism in these regions related to their roles in sex differences in physiology and behaviour.
Collapse
Affiliation(s)
- Rong‐Jun Ni
- Psychiatric Laboratory and Mental Health CenterWest China Hospital of Sichuan UniversityChengduChina
- Huaxi Brain Research CenterWest China Hospital of Sichuan UniversityChengduChina
| | - Yu‐Mian Shu
- School of Architecture and Civil EngineeringChengdu UniversityChengduChina
| | - Peng‐Hao Luo
- Chinese Academy of Science Key Laboratory of Brain Function and DiseasesSchool of Life SciencesUniversity of Science and Technology of ChinaHefeiChina
| | - Jiang‐Ning Zhou
- Chinese Academy of Science Key Laboratory of Brain Function and DiseasesSchool of Life SciencesUniversity of Science and Technology of ChinaHefeiChina
| |
Collapse
|
2
|
Cooper CE. Endocrinology of osmoregulation and thermoregulation of Australian desert tetrapods: A historical perspective. Gen Comp Endocrinol 2017; 244:186-200. [PMID: 26449158 DOI: 10.1016/j.ygcen.2015.10.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 09/30/2015] [Accepted: 10/03/2015] [Indexed: 10/22/2022]
Abstract
Many Australian tetrapods inhabit desert environments characterised by low productivity, unpredictable rainfall, high temperatures and high incident solar radiation. Maintaining a homeostatic milieu intérieur by osmoregulation and thermoregulation are two physiological challenges faced by tetrapods in deserts, and the endocrine system plays an important role in regulating these processes. There is a considerable body of work examining the osmoregulatory role of antidiuretic hormones for Australian amphibians, reptiles and mammals, with particular contributions concerning their role and function for wild, free-living animals in arid environments. The osmoregulatory role of the natriuretic peptide system has received some attention, while the role of adrenal corticosteroids has been more thoroughly investigated for reptiles and marsupials. The endocrinology of thermoregulation has not received similar attention. Reptiles are best-studied, with research examining the influence of arginine vasotocin and melatonin on body temperature, the role of prostaglandins in heart rate hysteresis and the effect of melanocyte-stimulating hormone on skin reflectivity. Australian mammals have been under-utilised in studies examining the regulation, development and evolution of endothermy, and there is little information concerning the endocrinology of thermoregulation for desert species. There is a paucity of data concerning the endocrinology of osmoregulation and thermoregulation for Australian desert birds. Studies of Australian desert fauna have made substantial contributions to endocrinology, but there is considerable scope for further research. A co-ordinated approach to examine arid-habitat adaptations of the endocrine system in an environmental and evolutionary context would be of particular value.
Collapse
Affiliation(s)
- Christine Elizabeth Cooper
- Department of Environment and Agriculture, Curtin University, Perth, Western Australia 6847, Australia; School of Animal Biology, University of Western Australia, Crawley, Western Australia 6009, Australia.
| |
Collapse
|
3
|
Yadawa AK, Chaturvedi CM. Expression of stress hormones AVP and CRH in the hypothalamus of Mus musculus following water and food deprivation. Gen Comp Endocrinol 2016; 239:13-20. [PMID: 26965951 DOI: 10.1016/j.ygcen.2016.03.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 02/04/2016] [Accepted: 03/05/2016] [Indexed: 01/24/2023]
Abstract
Neurohypophyseal hormone, arginine vasopressin (AVP), in addition to acting as antidiuretic hormone is also considered to be stress hormone like hypothalamic corticotropin-releasing hormone (CRH). Present study was designed to investigate the relative response of these stress hormones during water and food deprivation. In this study, male laboratory mice of Swiss strain were divided in 5 groups, control - provided water and food ad libitum, two experimental groups water deprived for 2 and 4days respectively (WD2 and WD4) and another two groups food deprived for 2 and 4days respectively (FD2 and FD4). Results indicate an increased expression of AVP mRNA as well as peptide in the hypothalamus of WD2 mice and the expression was further upregulated after 4days of water deprivation but the expression of CRH remained unchanged compare to their respective controls. On the other hand no change was observed in the expression of hypothalamic AVP mRNA while AVP peptide increased significantly in FD2 and FD4 mice compare to control. Further, the expression of CRH mRNA although increased in hypothalamus of both FD2 and FD4 mice, the immunofluorescent staining shows decreased expression of CRH in PVN of food deprived mice. Based on these findings it is concluded that since during osmotic stress only AVP expression is upregulated but during metabolic stress i.e. food deprivation transcription and translation of both the stress hormones are differentially regulated. Further, it is suggested that role of AVP and CRH may be stress specific.
Collapse
Affiliation(s)
- Arun Kumar Yadawa
- Department of Zoology, Banaras Hindu University, Varanasi 221005, India
| | | |
Collapse
|
4
|
Goerlich VC, Nätt D, Elfwing M, Macdonald B, Jensen P. Transgenerational effects of early experience on behavioral, hormonal and gene expression responses to acute stress in the precocial chicken. Horm Behav 2012; 61:711-8. [PMID: 22465454 DOI: 10.1016/j.yhbeh.2012.03.006] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Revised: 03/13/2012] [Accepted: 03/15/2012] [Indexed: 12/18/2022]
Abstract
Stress during early life can profoundly influence an individual's phenotype. Effects can manifest in the short-term as well as later in life and even in subsequent generations. Transgenerational effects of stress are potentially mediated via modulation of the hypothalamic-pituitary-adrenal axis (HPA) as well as epigenetic mechanisms causing heritable changes in gene expression. To investigate these pathways we subjected domestic chicken (Gallus gallus) to intermittent social isolation for the first three weeks of life. The early life stress resulted in a dampened corticosterone response to restraint stress in affected birds and in their male offspring. Stress-specific genes, such as early growth response 1 (EGR1) and corticotropin releasing hormone receptor 1 (CRHR1), were upregulated immediately after restraint stress, but not under baseline conditions. Treatment differences in gene expression were also correlated across generations which indicate transgenerational epigenetic inheritance. In an associative learning test early stressed birds made more correct choices suggesting a higher coping ability in stressful situations. This study is the first to show transgenerational effects of early life stress in a precocial species by combining behavioral, endocrinological, and transcriptomic measurements.
Collapse
MESH Headings
- Algorithms
- Animals
- Animals, Domestic
- Behavior, Animal/physiology
- Brain/metabolism
- Chickens/genetics
- Chickens/physiology
- Cohort Effect
- Female
- Gene Expression Regulation/physiology
- Male
- Models, Biological
- Physical Conditioning, Animal/methods
- Physical Conditioning, Animal/psychology
- Restraint, Physical/physiology
- Restraint, Physical/psychology
- Stress, Psychological/epidemiology
- Stress, Psychological/genetics
- Stress, Psychological/physiopathology
- Time Factors
Collapse
Affiliation(s)
- Vivian C Goerlich
- IFM Biology, Division of Zoology, Avian Behavioural Genomics and Physiology Group, Linköping University, Sweden
| | | | | | | | | |
Collapse
|
5
|
Ohuchi H, Yamashita T, Tomonari S, Fujita-Yanagibayashi S, Sakai K, Noji S, Shichida Y. A non-mammalian type opsin 5 functions dually in the photoreceptive and non-photoreceptive organs of birds. PLoS One 2012; 7:e31534. [PMID: 22348098 PMCID: PMC3279408 DOI: 10.1371/journal.pone.0031534] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Accepted: 01/09/2012] [Indexed: 11/23/2022] Open
Abstract
A mammalian type opsin 5 (neuropsin) is a recently identified ultraviolet (UV)-sensitive pigment of the retina and other photosensitive organs in birds. Two other opsin 5-related molecules have been found in the genomes of non-mammalian vertebrates. However, their functions have not been examined as yet. Here, we identify the molecular properties of a second avian opsin 5, cOpn5L2 (chicken opsin 5-like 2), and its localization in the post-hatch chicken. Spectrophotometric analysis and radionucleotide-binding assay have revealed that cOpn5L2 is a UV-sensitive bistable pigment that couples with the Gi subtype of guanine nucleotide-binding protein (G protein). As a bistable pigment, it also shows the direct binding ability to agonist all-trans-retinal to activate G protein. The absorption maxima of UV-light-absorbing and visible light-absorbing forms were 350 and 521 nm, respectively. Expression analysis showed relatively high expression of cOpn5L2 mRNA in the adrenal gland, which is not photoreceptive but an endocrine organ, while lower expression was found in the brain and retina. At the protein level, cOpn5L2 immunoreactive cells were present in the chromaffin cells of the adrenal gland. In the brain, cOpn5L2 immunoreactive cells were found in the paraventricular and supraoptic nuclei of the anterior hypothalamus, known for photoreceptive deep brain areas. In the retina, cOpn5L2 protein was localized to subsets of cells in the ganglion cell layer and the inner nuclear layer. These results suggest that the non-mammalian type opsin 5 (Opn5L2) functions as a second UV sensor in the photoreceptive organs, while it might function as chemosensor using its direct binding ability to agonist all-trans-retinal in non-photoreceptive organs such as the adrenal gland of birds.
Collapse
Affiliation(s)
- Hideyo Ohuchi
- Department of Life Systems, Institute of Technology and Science, University of Tokushima Graduate School, Tokushima, Japan.
| | | | | | | | | | | | | |
Collapse
|
6
|
Fokidis HB, Deviche P. Brain Arginine Vasotocin Immunoreactivity Differs between Urban and Desert Curve-Billed Thrashers, Toxostoma curvirostre: Relationships with Territoriality and Stress Physiology. BRAIN, BEHAVIOR AND EVOLUTION 2012; 79:84-97. [DOI: 10.1159/000332766] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Accepted: 08/31/2011] [Indexed: 01/14/2023]
|
7
|
Lau KK, Yang Y, Cook GA, Wyatt RJ, Nishimura H. Control of aquaporin 2 expression in collecting ducts of quail kidneys. Gen Comp Endocrinol 2009; 160:288-94. [PMID: 19135443 DOI: 10.1016/j.ygcen.2008.12.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2008] [Revised: 11/25/2008] [Accepted: 12/07/2008] [Indexed: 10/21/2022]
Abstract
Birds and mammals are the only vertebrates that can concentrate urine. Avian kidneys contain structurally primitive loopless nephrons and also more advanced looped nephrons, in the cortical and medullary regions, respectively. We have identified the gene sequence of an aquaporin 2 (AQP2)-homologue water channel in collecting ducts of kidneys from adult quail, Coturnix japonica. Although immunoreactive quail AQP2 (qAQP2) was found in both types of nephrons, the expression is enhanced more clearly in the medullary regions after water deprivation. We therefore hypothesized that regulation of qAQP2 expression in quail kidneys via antidiuretic hormone (ADH) may require more advanced nephron structure. In this study, we determined the expression of qAQP2 mRNA in tissues isolated from the cortical and medullary regions before and after water deprivation, by conventional reverse transcriptase-polymerase chain reaction (RT-PCR) and quantitative real-time PCR. In both normally hydrated and water-deprived groups, qAQP2 mRNA levels in the medullary regions were significantly higher (P<0.01) than in the cortical regions. In medullary areas, qAQP2 mRNA levels (real-time PCR normalized with 18S) were significantly higher (P<0.01, ANOVA) after water deprivation (1.09+/-0.10) than in normally hydrated controls (0.46+/-0.08). In cortical areas, qAQP2 mRNA levels were also higher after water deprivation (0.37+/-0.05) than in controls (0.11+/-0.02). qAQP2 mRNA signals determined by in situ hybridization of digoxigenin-labeled riboprobe were also enhanced after water deprivation in both cortical and medullary collecting ducts. The results suggest that, contrary to our hypothesis, the endogenous production of ADH by water deprivation stimulates qAQP2 mRNA in both loopless and looped nephrons.
Collapse
Affiliation(s)
- Keith K Lau
- Department of Physiology, University of Tennessee Health Science Center, College of Medicine, Memphis, TN 38163, USA
| | | | | | | | | |
Collapse
|
8
|
Singh S, Chaturvedi CM. Changes in vasotocin immunoreactivity of paraventricular nuclei and adrenal function of Japanese quail in relation to different phases of sexual development. Domest Anim Endocrinol 2008; 34:293-300. [PMID: 17900850 DOI: 10.1016/j.domaniend.2007.08.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2007] [Revised: 08/08/2007] [Accepted: 08/10/2007] [Indexed: 10/22/2022]
Abstract
In relevance to osmoregulatory and reproductive functions, activity of hypothalamic neurosecretory neurons may also vary seasonally. The current study was performed to determine annual changes in ir-AVT neurons of hypothalamus and adrenal gland function. We examined changes in ir-AVT neuron by immunohistochemical method and plasma testosterone was measured by enzyme immunoassay. The steroidogenic interrenal activity was studied by histological and biochemical methods. Birds were sampled in February (quiescent), April (recrudescent), June (breeding) and November (regressive). A significant and gradual increase in the number of ir-AVT neurons was observed from quiescent to breeding phase which decreased during regressive phase of annual gonadal cycle. The gradual increase in ir-AVT neurons along with annual gonadal activity of quail were accompanied by increase in plasma levels of testosterone. These results indicate a functional interaction between sex steroid and AVT synthesizing neurons. Adrenal activity (as judged by weight, ascorbic acid content, cortical cord width and cortico-medullary ratio) was also maximum during breeding phase. It is thus postulated that domesticated quail when exposed to natural day length (NDL), exhibits seasonal/annual cyclicity in vastocinergic activity and adrenal function which may be due to difference in sex steroid hormone.
Collapse
Affiliation(s)
- Sajla Singh
- Molecular Endocrinology Lab, Department of Zoology, Banaras Hindu University, Varanasi 221005, UP, India.
| | | |
Collapse
|
9
|
Madison FN, Jurkevich A, Kuenzel WJ. Sex differences in plasma corticosterone release in undisturbed chickens (Gallus gallus) in response to arginine vasotocin and corticotropin releasing hormone. Gen Comp Endocrinol 2008; 155:566-73. [PMID: 17936761 DOI: 10.1016/j.ygcen.2007.08.014] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2007] [Revised: 08/15/2007] [Accepted: 08/16/2007] [Indexed: 10/22/2022]
Abstract
In birds, two neuropeptides, corticotropin releasing hormone (CRH) and arginine vasotocin (AVT), are major regulators of the hypothalamo-pituitary-adrenal axis (HPA) during the stress response. In birds, however, the relative efficacy of CRH and AVT to stimulate the HPA axis in males and females remains unknown. The purpose of this study was to determine the time course of CORT release following central CRH and AVT administration to male and female chickens. Chickens were fitted with a stainless steel cannula surgically implanted in the lateral ventricle and a catheter chronically inserted in the jugular vein. Birds were housed individually in cages behind a one-way glass partition and unnecessary noise was avoided during the sampling period. Each bird received a single 5.0microtracerebroventricular (ICV) injection of either saline (SAL), AVT (10 and 100pmol), or CRH (10 and 100pmol). Blood was sampled remotely every 15min for 2h and plasma CORT was determined by radioimmunoassay. There was a significant increase in plasma CORT concentration in males injected with 100pmol AVT beginning at 15min post-injection through 2h compared with SAL injected birds. In males, injection of 100pmol CRH was significantly more effective in releasing CORT compared to an equal molar concentration of AVT or SAL. In females, ICV injection of 100pmol AVT induced moderate increase in CORT levels. In contrast, 100pmol CRH significantly increased plasma CORT compared to SAL injected controls but the CORT response was nearly 50% less than that obtained in males.
Collapse
Affiliation(s)
- F N Madison
- Department of Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA.
| | | | | |
Collapse
|
10
|
Srivastava R, Cornett LE, Chaturvedi CM. Effect of photoperiod and estrogen on expression of arginine vasotocin and its oxytocic-like receptor in the shell gland of the Japanese quail. Comp Biochem Physiol A Mol Integr Physiol 2007; 148:451-7. [PMID: 17627858 DOI: 10.1016/j.cbpa.2007.06.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2006] [Revised: 06/09/2007] [Accepted: 06/10/2007] [Indexed: 11/23/2022]
Abstract
The avian neurohypophysial hormone arginine vasotocin (AVT) is an important regulatory hormone involved in many physiological processes including fluid balance, blood pressure regulation, stress responses and reproductive events including oviposition. The mechanisms by which AVT stimulates myometrial contraction during oviposition are not well established in birds. In the present study, immunohistochemistry and in situ hybridization were used to localize AVT and the oxytocin-like VT3 receptor in the shell gland of Japanese quail (Coturnix coturnix japonica). Using an AVT-specific antibody, immunoreactive AVT (ir-AVT) was observed in the myometrium of both photosensitive and photorefractory birds. Similarly, VT3 receptor gene transcripts were detected in the myometrial layer of the shell gland of both photosensitive and photorefractory birds. Body mass, shell gland mass and length of mucosal folds of the shell gland of photosensitive birds was higher compared to that of photorefractory birds. Treatment of photorefractory birds with estrogen increased shell gland activity (mass and length of mucosal folds) and levels of both AVT and VT3 receptor mRNA, whereas treatment of photosensitive birds with the estrogen antagonist tamoxifen decreased shell gland activity and levels of both AVT and VT3 receptor mRNA. Our results suggest that shell gland contractility in response to AVT may be regulated during the reproductive cycle of the Japanese quail and that, in part, this regulation is estrogen-dependent.
Collapse
Affiliation(s)
- Rashmi Srivastava
- Department of Zoology, Banaras Hindu University, Varanasi, 221005, India
| | | | | |
Collapse
|
11
|
Goldstein DL. Regulation of the avian kidney by arginine vasotocin. Gen Comp Endocrinol 2006; 147:78-84. [PMID: 16288753 DOI: 10.1016/j.ygcen.2005.09.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2005] [Revised: 09/07/2005] [Accepted: 09/21/2005] [Indexed: 11/19/2022]
Abstract
Nonapeptides secreted by the neurohypophysis have important roles in vertebrate cardio-fluid homeostasis. In birds, those peptides include mesotocin (the representative of the neutral, or oxytocin-like, nonapeptide family) and vasotocin (the representative of the basic, or vasopressin-like, hormones). The function of mesotocin is not well defined, but it does appear to have osmoregulatory functions. Vasotocin is considered the primary avian antidiuretic hormone. Receptors for AVT in avian kidney-either on renal vasculature or on the tubules-have yet to be localized or identified. However, AVT quite certainly effects antidiuresis via both vascular and tubular mechanisms. The former entail a reduction in the rate of glomerular filtration, apparently via constriction of afferent arterioles. Evidence for the latter (direct tubular action of AVT) has accumulated in recent years and includes enhanced fractional tubular water reabsorption, activation of second messenger (cAMP) in thick ascending limbs and collecting ducts, and modest AVT-stimulated water permeability in collecting ducts associated with expression of aquaporins. The relative importance of the renal vascular vs. tubular actions in birds likely depend on the dose of the hormone, the physiological condition of the animal, and the species of bird.
Collapse
Affiliation(s)
- David L Goldstein
- Department of Biological Sciences, Wright State University, Dayton, OH 45435, USA.
| |
Collapse
|
12
|
Singh S, Chaturvedi CM. Effect of long and short photoperiod on vasotocin neurons of paraventricular nuclei and adrenal function of water deprived Japanese quail. Comp Biochem Physiol A Mol Integr Physiol 2006; 143:202-10. [PMID: 16406272 DOI: 10.1016/j.cbpa.2005.11.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2005] [Revised: 11/17/2005] [Accepted: 11/21/2005] [Indexed: 10/25/2022]
Abstract
The responses of magnocellular neurons of paraventricular nuclei (PVN) and changes to adrenal activity to water deprivation in Japanese quail maintained under gonado-inhibitory and stimulatory photoperiods were examined. Water deprivation of 4 days resulted in a 12% decrease in body weight of sexually regressed short day (SD, 6L:18D) quail, while the decrease was more (18%) in sexually stimulated long day (LD, 16L:8D) quail. The increase in plasma osmolality following water deprivation was also more (47%) in LD than to SD quail (36%). Under the LD condition, quail had increased numbers, sizes and immunostaining of ir-AVT neurons of PVN compared to SD condition. A significant increase in the number of ir-AVT neurons was observed following 4 days of water deprivation in both SD and LD quail compared to their respective fully hydrated controls. However, the degree of response was more under the LD compared to the SD condition suggesting that gonado-stimulatory long days increase the activity/response of the AVT system. Increased adrenal ascorbic acid content (i.e., activity) was also observed to quail of LD when compared to SD treatment. However, osmotic stress led to adrenal hypertrophy and hyperactivity of quail of both of the photoperiodic regimes. Our findings indicate that not only osmotic stress but also photo-gonadal stimulation upregulates the expression of hypothalamic AVT genes and increases the localization of ir-AVT in many neurons of PVN. The above results support the existence of a parallel adrenal-gonad relationship and increase in adrenal function during osmotic stress, which also leads to simultaneous increase in AVT system. We conclude that photo-sexual conditions alter hypothalamic vasotocinergic and adrenal activity in Japanese quail and the degree of stimulation of the two systems following osmotic stress is higher under gonado-stimulatory LD conditions.
Collapse
Affiliation(s)
- Sajla Singh
- Department of Zoology, Molecular Endocrinology Lab Banaras Hindu University, Varanasi -221005 (UP), India.
| | | |
Collapse
|
13
|
Konno N, Hyodo S, Takei Y, Matsuda K, Uchiyama M. Plasma aldosterone, angiotensin II, and arginine vasotocin concentrations in the toad, Bufo marinus, following osmotic treatments. Gen Comp Endocrinol 2005; 140:86-93. [PMID: 15613270 DOI: 10.1016/j.ygcen.2004.10.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2004] [Revised: 09/22/2004] [Accepted: 10/12/2004] [Indexed: 10/26/2022]
Abstract
To clarify the physiological roles of the renin-angiotensin-aldosterone system (RAAS) and arginine vasotocin (AVT) on body fluid regulation in amphibians, we measured plasma concentrations of aldosterone (ALDO), angiotensin II (ANG II), and AVT after various osmotic challenges in the marine toad, Bufo marinus (Bufonidae). Hematocrit value (Ht) as an indicator of plasma volume, plasma osmolality and concentrations of plasma components (Na(+), Cl(-), K(+), and urea) were also measured. The toads were maintained under various osmotic treatments for 7 days. In dehydrated toads, plasma concentrations of ALDO, ANG II, AVT, and all plasma components measured were increased. In toads maintained in 300 mosmol/kg H(2)O NaCl solution, plasma osmolality, Na(+), Cl(-), urea, and plasma AVT concentrations were significantly increased, and Ht and plasma concentrations of ALDO and ANG II were significantly decreased. In toads maintained in tap water, plasma osmolality, and concentrations of Na(+) and ALDO were significantly decreased. We also estimated total body water (TBW), plasma volume (PV) using Evans Blue dye and Ht in the toads under various osmotic treatments. In dehydrated toads, TBW and PV were significantly decreased and Ht was significantly increased in comparison with those of control. In toads maintained in 300 mosmol/kg H(2)O NaCl solution, TBW and PV were significantly increased and Ht was significantly decreased in comparison with those of control. There was a significant negative correlation between Ht and PV or TBW. These results show that dehydration, which induces hypovolemic and hyperosmotic conditions, stimulates increases of plasma ALDO, ANG II, and AVT concentrations, while hypervolemic treatment induces decreases of plasma ALDO and ANG II concentrations. There were significant correlations between plasma osmolality and AVT concentration, between Ht and concentrations of RAAS hormones, and between plasma concentrations of ALDO and ANG II. These results suggest that volumetric and osmometric systems regulated by RAAS hormones and AVT are present in B. marinus.
Collapse
Affiliation(s)
- Norifumi Konno
- Department of Biology, Faculty of Science, Toyama University, Toyama 930-8555, Japan
| | | | | | | | | |
Collapse
|
14
|
Seth R, Köhler A, Grossmann R, Chaturvedi CM. Expression of hypothalamic arginine vasotocin gene in response to water deprivation and sex steroid administration in female Japanese quail. J Exp Biol 2004; 207:3025-33. [PMID: 15277557 DOI: 10.1242/jeb.01118] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
SUMMARY
Arginine vasotocin (AVT) is a neurohypophyseal hormone involved in reproductive function and control of osmoregulation in birds. In view of the dual function of AVT, the present experiment was designed to observe the effect of water deprivation (WD) and sex steroid [estradiol benzoate (EB) and testosterone propionate (TP)] treatment independently, as well as simultaneously, on the profile/activity of the hypothalamic AVT system. WD resulted in a significant increase in plasma osmolality, sodium ion concentration and AVT concentration, but administration of sex steroids had no significant influence on these parameters. By contrast, the amount of hypothalamic AVT transcript (northern analysis) and the size of immunoreactive vasotocin (ir-AVT) neurons and hybridization signals (in the form of silver grains), representing AVT mRNA in corresponding neurons of paraventricular nuclei (PVN), increased significantly in all the treated groups compared with controls. Our findings indicate that although sex steroid administration has no effect on plasma osmolality and AVT concentration, unlike water deprivation, it may stimulate the profile/activity of AVT neurons of PVN,supporting the possibility of sex steroid receptors on these neurons. It is concluded that in quail, osmotic stress not only upregulates the expression of the AVT gene in existing neurons but also recruits many more neurons to increase the rate of AVT synthesis and secretion, while sex steroids appear to have a stimulatory effect only on the existing number of neurons and only at the level of transcription/translation and hence may influence/modulate hypothalamic AVT gene expression in response to osmotic stress. This study also suggests an interrelationship between reproduction and AVT system/function in birds.
Collapse
Affiliation(s)
- R Seth
- Department of Zoology, Banaras Hindu University, Varanasi-221 005 (UP), India
| | | | | | | |
Collapse
|
15
|
Abstract
This study explored the effects of gender and aging on the complexity of cardiac pacemaker activity. Electrocardiogram signals were studied in normal women (n = 240) and men (n = 240) ranging in age from 40 to 79 yr. Nonlinear analysis of short-term resting R-R intervals was performed using the correlation dimension (CD), approximate entropy (ApEn), and largest Lyapunov exponent (LLE). Evidence of nonlinear structure was obtained by the surrogate data test. CD, ApEn, and LLE were negatively correlated with age. Despite similar means and SDs of the R-R intervals, women had a significantly higher CD, ApEn, and LLE compared with men in the age strata of 40-44 and 45-49 yr. CD and ApEn were strongly (r > 0.71) correlated with low- and high-frequency components. We conclude that the resting cardiac pacemaker activity of women is more complex than that of men in middle age, and the gender-related difference diminishes after the age of 50 yr. The higher complexity implies a more comprehensive neural modulation.
Collapse
|
16
|
Grossmann R, Jurkevich A, Köhler A. Sex dimorphism in the avian arginine vasotocin system with special emphasis to the bed nucleus of the stria terminalis. Comp Biochem Physiol A Mol Integr Physiol 2002; 131:833-7. [PMID: 11897194 DOI: 10.1016/s1095-6433(02)00021-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The avian neuropeptide arginine vasotocin (AVT) originally characterized as the antidiuretic hormone (, Endocrinol. 66, 860-871) is produced by neurosecretory cells within the brain. Numerous neuroanatomical studies that employed immunocytochemical and in situ hybridization techniques revealed such cells in the following anatomical brain locations: (a) preoptic area including supraoptic nucleus; (b) paraventricular nucleus; (c) the bed nucleus of the stria terminalis (BnST) (, J. Hirnforsch. 27, 559-566;, J. Neuroendcrinol. 5, 281-288;, Cell Tiss. Res. 287, 69-77;, J. Comp. Neurol. 369, 141-157). The BnST which influences reproduction and sexual behavior shows sex differences in morphology, steroid responsiveness and synthesis of neuropeptides including AVT (, Brain Res. 657, 171-184). AVT is the main endocrine regulator of fluid balance in avian species and, in addition, is involved in oviposition in these species. Our recent studies clearly demonstrated that AVT secretion after osmotic stimulation is sexually dimorphic. In order to investigate whether AVT is expressed and synthesized in the BnST in a sexually dimorphic manner we have used in situ hybridization technique and immunocytochemistry to analyze AVT gene expressing neurons in the parvocellular (small-celled nulei) BnST of adult male and female chickens. In cocks, AVT peptide-containing neurons were detected in the parvocellular BnST and the lateral septal area, whereas no AVT immunoreactive neurons were detected in the corresponding regions of the hen. Even after osmotic stimulation AVT gene expression in neurons of the parvocellular BnST of hens was not upregulated (, Cell Tiss. Res. 287, 69-77). These results demonstrate: (a) AVT gene expression in the BnST of chickens; and (b) a strong sexual dimorphism in this region. Furthermore, AVT synthesis is regulated on the transcriptional level independent from osmotic stimuli. Thus, sex steroids might be the main regulator of AVT gene expression in the BnST. In this paper we not only review the sexual dimorphic vasotocinergic system in the BnST, we also focus on the ontogeny of sex differences and the role of gonadal hormones in organization and retention of these differences.
Collapse
Affiliation(s)
- Roland Grossmann
- Institute for Animal Science and Animal Behaviour, Federal Agricultural Research Centre, D-29223 Celle, Germany.
| | | | | |
Collapse
|