Roles of arginine vasotocin receptors in the brain and pituitary of submammalian vertebrates.
Hasunuma Itaru,Toyoda Fumiyo,Okada Reiko,Yamamoto Kazutoshi,Kadono Yoshihiko,Kikuyama Sakae
International review of cell and molecular biology
This chapter reviews the functions of arginine vasotocin (AVT) and its receptors in the central nervous system (CNS) of primarily submammalian vertebrates. The V1a-type receptor, which is widely distributed in the CNS of birds, amphibians, and fish, is one of the most important receptors involved in the expression of social and reproductive behaviors. In mammals, the V1b receptor of arginine vasopressin, an AVT ortholog, is assumed to be involved in aggression, social memory, and stress responses. The distribution of the V1b-type receptor in the brain of submammalian vertebrates has only been reported in an amphibian species, and its putative functions are discussed in this review. The functions of V2-type receptor in the CNS are still unclear. Recent phylogenetical and pharmacological analyses have revealed that the avian VT1 receptor can be categorized as a V2b-type receptor. The distribution of this newly categorized VT1 receptor in the brain of avian species should contribute to our knowledge of the possible roles of the V2b-type receptor in the CNS of other nonmammalian vertebrates. The functions of AVT in the amphibian and avian pituitaries are also discussed, focusing on the V1b- and V1a-type receptors.
10.1016/B978-0-12-407696-9.00004-X
Feeding response following central administration of mesotocin and arginine-vasotocin receptor agonists in chicks (Gallus gallus).
Masunari Kazuya,Cline Mark A,Khan Sakirul Islam,Tachibana Tetsuya
Physiology & behavior
Mesotocin (MT) and arginine-vasotocin (AVT) are posterior pituitary derived hormones in birds and are homologous to mammalian oxytocin (OT) and vasopressin (VP), respectively. We previously reported that intracerebroventricular (ICV) injection of both MT and AVT inhibit feeding and induce wing-flapping in chicks (Gallus gallus). Because both peptides cause similar effects suggests that they might act via common receptors. However, the specific receptors of MT and AVT which mediate their anorexigenic effect have not been clarified in chicks. Thus, the purpose of the present study was to identify the receptor subtypes involved in MT- and AVT-induced anorexia and behavioral patterns by using several agonists. ICV injection of vasopressin-1 receptor agonist (V1R) (homologous to chicken AVT receptor-2 and -4 [VT2R and VT4R, respectively]), significantly decreased food intake while agonists of vasopressin-2 receptor (V2R) and OT receptor (OTR) (homologues of chicken AVT receptor-1 and MT receptor respectively) had no effect. In addition, V1R agonist induced wing-flapping although this was not affected by V2R or OTR agonists. Since VT2R has not been found in the brain of chicks, the present study suggested that VT4R might be related to the anorexigenic effect and wing-flapping induced by MT and AVT in chicks.
10.1016/j.physbeh.2015.11.001
Impact of estrogen and photoperiod on arginine vasotocin and VT3 receptor expression in the shell gland of quail.
Srivastava Rashmi,Cornett Lawrence E,Chaturvedi Chandra Mohini
Frontiers in bioscience (Scholar edition)
Role of estrogen and photoperiod is well-established in avian reproduction. In addition, the distribution and the expression of arginine vasotocin (AVT) and its receptor VT3 to ensure reproductive/breeding conditions in Japanese quail influenced by them has been the main focus of this review. To consider this aspect the mRNA expression of VT3 receptor and its ligand AVT in the shell gland has been emphasized. In birds, AVT performs a dual role as an anti-diuretic hormone and the functions accomplished by oxytocin in mammals. The physiological actions of AVT in birds are mediated through its diverse receptor subtypes VT1, VT2, VT3 and VT4. Dynamic alteration of VT3 expression during different reproductive and photo-sexual conditions of quail can be modulated by estrogen. In addition to the endocrine effect of AVT, the shell gland is complemented by its paracrine action via its receptors. Evidences indicate that the expression of shell gland AVT modulated by estrogen appears to play a priming role by modulating the availability of VT3 receptor for the required action of neurohypophysial AVT during oviposition.
10.2741/S522
Species, sex and individual differences in the vasotocin/vasopressin system: relationship to neurochemical signaling in the social behavior neural network.
Albers H Elliott
Frontiers in neuroendocrinology
Arginine-vasotocin (AVT)/arginine vasopressin (AVP) are members of the AVP/oxytocin (OT) superfamily of peptides that are involved in the regulation of social behavior, social cognition and emotion. Comparative studies have revealed that AVT/AVP and their receptors are found throughout the "social behavior neural network (SBNN)" and display the properties expected from a signaling system that controls social behavior (i.e., species, sex and individual differences and modulation by gonadal hormones and social factors). Neurochemical signaling within the SBNN likely involves a complex combination of synaptic mechanisms that co-release multiple chemical signals (e.g., classical neurotransmitters and AVT/AVP as well as other peptides) and non-synaptic mechanisms (i.e., volume transmission). Crosstalk between AVP/OT peptides and receptors within the SBNN is likely. A better understanding of the functional properties of neurochemical signaling in the SBNN will allow for a more refined examination of the relationships between this peptide system and species, sex and individual differences in sociality.
10.1016/j.yfrne.2014.07.001
Arginine Vasotocin Preprohormone Is Expressed in Surprising Regions of the Teleost Forebrain.
Rodriguez-Santiago Mariana,Nguyen Jessica,Winton Lin S,Weitekamp Chelsea A,Hofmann Hans A
Frontiers in endocrinology
Nonapeptides play a fundamental role in the regulation of social behavior, among numerous other functions. In particular, arginine vasopressin and its non-mammalian homolog, arginine vasotocin (AVT), have been implicated in regulating affiliative, reproductive, and aggressive behavior in many vertebrate species. Where these nonapeptides are synthesized in the brain has been studied extensively in most vertebrate lineages. While several hypothalamic and forebrain populations of vasopressinergic neurons have been described in amniotes, the consensus suggests that the expression of AVT in the brain of teleost fish is limited to the hypothalamus, specifically the preoptic area (POA) and the anterior tuberal nucleus (putative homolog of the mammalian ventromedial hypothalamus). However, as most studies in teleosts have focused on the POA, there may be an ascertainment bias. Here, we revisit the distribution of AVT preprohormone mRNA across the dorsal and ventral telencephalon of a highly social African cichlid fish. We first use hybridization to map the distribution of AVT preprohormone mRNA across the telencephalon. We then use quantitative real-time polymerase chain reaction to assay AVT expression in the dorsomedial telencephalon, the putative homolog of the mammalian basolateral amygdala. We find evidence for AVT preprohormone mRNA in regions previously not associated with the expression of this nonapeptide, including the putative homologs of the mammalian extended amygdala, hippocampus, striatum, and septum. In addition, AVT preprohormone mRNA expression within the basolateral amygdala homolog differs across social contexts, suggesting a possible role in behavioral regulation. We conclude that the surprising presence of AVT preprohormone mRNA within dorsal and medial telencephalic regions warrants a closer examination of possible AVT synthesis locations in teleost fish, and that these may be more similar to what is observed in mammals and birds.
10.3389/fendo.2017.00195
Arginine Vasotocin, the Social Neuropeptide of Amphibians and Reptiles.
Wilczynski Walter,Quispe Maricel,Muñoz Matías I,Penna Mario
Frontiers in endocrinology
Arginine vasotocin (AVT) is the non-mammalian homolog of arginine vasopressin (AVP) and, like vasopressin, serves as an important modulator of social behavior in addition to its peripheral functions related to osmoregulation, reproductive physiology, and stress hormone release. In amphibians and reptiles, the neuroanatomical organization of brain AVT cells and fibers broadly resembles that seen in mammals and other taxa. Both parvocellular and magnocellular AVT-containing neurons are present in multiple populations located mainly in the basal forebrain from the accumbens-amygdala area to the preoptic area and hypothalamus, from which originate widespread fiber connections spanning the brain with a particularly heavy innervation of areas associated with social behavior and decision-making. As for mammalian AVP, AVT is present in greater amounts in males in many brain areas, and its presence varies seasonally, with hormonal state, and in males with differing social status. AVT's social influence is also conserved across herpetological taxa, with significant effects on social signaling and aggression, and, based on the very small number of studies investigating more complex social behaviors in amphibians and reptiles, AVT may also modulate parental care and social bonding when it is present in these vertebrates. Within this conserved pattern, however, both AVT anatomy and social behavior effects vary significantly across species. Accounting for this diversity represents a challenge to understanding the mechanisms by which AVT exerts its behavioral effects, as well are a potential tool for discerning the structure-function relationships underlying AVT's many effects on behavior.
10.3389/fendo.2017.00186
Variation in brain arginine vasotocin (AVT) and isotocin (IT) levels with reproductive stage and social status in males of three-spined stickleback (Gasterosteus aculeatus).
Kleszczyńska Agnieszka,Sokołowska Ewa,Kulczykowska Ewa
General and comparative endocrinology
Arginine vasotocin (AVT) and isotocin (IT) are fish nonapeptides synthesized in separate hypothalamic neurons from where they are transported to the neurohypophysis for storage and release into circulation. AVT is known to modulate aggression, courtship and parental care or social communication in many species, including fish, amphibians and birds. In this paper we examined a link between the level of AVT and IT in the brain and particular reproductive behavior in males of three-spined stickleback (Gasterosteus aculeatus). AVT and IT levels in whole brain of males of three-spined stickleback vary depending on specific breeding behavior of the individuals and their social status. These studies have shown the highest AVT levels in aggressive males that took care of the eggs. Brain AVT concentrations are also increased in nuptial colored subordinate males that fight to change their social status. On the other hand, IT is significantly higher in aggressive dominant males that defend their territory. IT may be also involved in courtship in three-spined stickleback. These findings highlight the importance of determination of "free", bioavailable neuropeptides' level in behavioral studies.
10.1016/j.ygcen.2011.11.022
Arginine vasotocin treatment induces a stress response and exerts a potent anorexigenic effect in rainbow trout, Oncorhynchus mykiss.
Gesto M,Soengas J L,Rodríguez-Illamola A,Míguez J M
Journal of neuroendocrinology
The peptide arginine vasotocin (AVT), homologous to mammalian arginine vasopressin, is involved in many aspects of fish physiology, such as osmoregulation, regulation of biological rhythms, reproduction, metabolism or responses to stress, and the modulation of social behaviours. Because a decrease in appetite is a general response to stress in fish and other vertebrates, we investigated the role of AVT as a possible food intake regulator in fish. We used i.c.v. injections for central administration of AVT to rainbow trout (Oncorhynchus mykiss). In a first experiment, we evaluated the temporal response of food intake after AVT treatment. In a second experiment, we investigated the effects of central AVT administration on the response of typical stress markers (plasma cortisol, glucose and lactate), as well as brain serotonergic, noradrenergic and dopaminergic activity. In addition, the mRNA levels of genes involved in food intake regulation [neuropetide Y, pro-opiomelanocortin (POMC), cocaine- and amphetamine-regulated transcript (CART) and corticotrophin-releasing factor (CRF)] and in CRF- (CRF-binding protein) and AVT-signalling (pro-VT and AVT receptor), were also assessed after AVT treatment. Our results showed that AVT is a potent anorexigenic factor in fish. Increases of plasma cortisol and glucose after AVT treatment strongly suggest that AVT administration induced a stress response and that AVT action was mediated by hypothalamic-pituitary-interrenal axis activation, which was also supported by the increase of the serotonergic activity in trout telencephalon and hypothalamus. The increased hypothalamic levels of POMC and CART suggest that these peptides might have a role in the anorexigenic action of AVT, whereas the involvement of CRF signalling is unclear.
10.1111/jne.12126
Intracerebroventricular administration of arginine vasotocin (AVT) induces anorexigenesis and anxiety-like behavior in goldfish.
Araishi Koh,Watanabe Keisuke,Yamazaki Takumi,Nakamachi Tomoya,Matsuda Kouhei
Peptides
Arginine vasotocin (AVT) is known as a neurohypophyseal hormone that regulates water- and mineral-balance in non-mammalian vertebrates. Recent studies revealed that AVT also exerts central effects on behavior. The goldfish has several merits for evaluation of behavioral changes. However, there is few information on the behavioral action of AVT in this species. Here we examined the effects of AVT on food intake and psychomotor activity. AVT was administered intracerebroventricularly at 1, 5 and 10 pmol g body weight (BW). Intracerebroventricular (ICV) administration of AVT at 5 and 10 pmol g BW significantly decreased food intake during 30 min after injection and recovery from anesthesia. The AVT-induced anorexigenic action was attenuated by treatment with the AVT receptor V1aR antagonist Manning compound (MC) at 50 pmol g BW. As the goldfish tends to prefer the lower to the upper area of a tank, we used this preference behavior for assessing psychomotor activity during a 30-min observation period. ICV administration of AVT at 1, 5 and 10 pmol g BW significantly prolonged the time spent in the lower area, but did not affect locomotor activity in the tank at any dose. The action of AVT was similar to that of the central-type benzodiazepine receptor inverse agonist FG-7142 at 10 pmol g BW. AVT-induced anxiety-like behavior was blocked by treatment with MC at 50 pmol g BW. These results indicate that AVT affects food intake and psychophysiological status, and also induces anorexigenic- and anxiogenic-like actions via the V1aR-signaling pathway in the goldfish brain.
10.1016/j.peptides.2019.170118
Arginine vasotocin (AVT)/mesotocin (MT) receptors in chickens: Evidence for the possible involvement of AVT-AVPR1 signaling in the regulation of oviposition and pituitary prolactin expression.
Wu Chao,Lv Can,Wan Yiping,Li Xiaoxiao,Zhang Jiannan,Li Juan,Wang Yajun
General and comparative endocrinology
Two structurally related peptides, arginine vasotocin (AVT) and mesotocin (MT), are reported to regulate many physiological processes, such as anti-diuresis and oviposition in birds, and their actions are likely mediated by four AVT/MT receptors (AVPR1A, AVPR1B, MTR and AVPR2b), which are orthologous/paralogous to human AVPR1A, AVPR1B, OXTR and AVPR2 respectively. However, our knowledge regarding the functions of these avian AVT/MT receptors has been limited. Here, we examined the functionality and expression of these receptors in chickens and investigated the roles of AVT in the anterior pituitary. Our results showed that 1) AVPR1A, AVPR1B and AVPR2b could be preferentially activated by AVT, monitored by cell-based luciferase reporter assays and/or Western blot, indicating that they are AVT-specific receptors (AVPR1A; AVPR1B) or AVT-preferring receptor (AVPR2b) functionally coupled to intracellular calcium, MAPK/ERK and cAMP/PKA signaling pathways. In contrast, MTR could be activated by AVT and MT with similar potencies, indicating that MTR is a receptor common for both peptides; 2) Using qPCR, differential expression of the four receptors was found in chicken tissues including the oviduct and anterior pituitary. In particular, only AVPR1A is abundantly expressed in the uterus, suggesting its involvement in mediating AVT-induced oviposition. 3) In cultured chick pituitary cells, AVT could stimulate ACTH and PRL expression and secretion, an action likely mediated by AVPR1B and/or AVPR1A abundantly expressed in anterior pituitary. Collectively, our data helps to elucidate the roles of AVT/MT in birds, such as the 'oxytocic action' of AVT, which induces uterine muscle contraction during oviposition.
10.1016/j.ygcen.2019.05.013
Identification of arginine vasotocin (AVT) neurons activated by acute and chronic restraint stress in the avian septum and anterior diencephalon.
Nagarajan Gurueswar,Tessaro Brian A,Kang Seong W,Kuenzel Wayne J
General and comparative endocrinology
Effects of acute and chronic psychological stress in the brain of domestic avian species have not been extensively studied. Experiments were performed using restraint stress to determine groups of neurons activated in the septum and diencephalon of chickens. Using FOS immunoreactivity six brain structures were shown activated by acute stress including: the lateral hypothalamic area (LHy), ventrolateral thalamic nucleus (VLT), lateral septum (LS), lateral bed nucleus of the stria terminalis (BSTL), nucleus of the hippocampal commissure (NHpC) and the core region of the paraventricular nucleus (PVNc). Additionally, the LHy and PVNc showed increased FOS immunoreactive (-ir) cells in the birds chronically stressed when compared to controls. In contrast, the NHpC showed decreased FOS-ir cells following the 10day chronic stress imposed. Thereafter, restraint stress experiments were performed to identify activated arginine vasotocin (AVT) neurons (parvocellular or magnocellular) using immunocytochemistry. Of the six FOS activated structures, the PVN was known to contain distinct size groups of AVT-ir neurons, parvocellular (small), medium sized and magnocellular (large). Using dual immunostaining (AVT/FOS), AVT-ir parvocellular neurons in the PVNc were found activated in both acute and chronic stress. To determine whether these AVT-ir parvocellular neurons are co-localized with corticotropin releasing hormone (CRH), an attempt was made to visualize CRH-ir neurons using colchicine. Although AVT-ir and CRH-ir parvocellular neurons occur in the PVNc, only a few neurons were shown co-localized with AVT and CRH after acute restraint stress. Results of this study suggest that the NHpC, LS, VLT, BSTL, LHy and AVT-ir parvocellular neurons in the PVNc are associated with psychological stress in birds.
10.1016/j.ygcen.2014.04.012