Chandra Mohini Chaturvedi

Bio: Chandra Mohini Chaturvedi is an academic researcher from Banaras Hindu University. The author has contributed to research in topics: Quail & Vasotocin. The author has an hindex of 19, co-authored 92 publications receiving 1161 citations. Previous affiliations of Chandra Mohini Chaturvedi include University of Arkansas for Medical Sciences.

2.45 GHz low level CW microwave radiation affects embryo implantation sites and single strand DNA damage in brain cells of mice, mus musculus

Abstract: To study the effect of microwave radiation on the early stages of pregnancy (implantation) and DNA damage in brain cells, female mice were exposed to 245 GHz electromagnetic field (EMF) for 2 hours/ day at power density of 01250 mW/cm2 for the period of 30 days (pre-mating period, 22 days; mating period, 5 days; post mating period, 3 days)

Interaction between serotonin and a dopamine precursor (given 8 hour apart) and luteinizing hormone alters reproductive and metabolic responses of migratory red headed bunting (Emberiza bruniceps)

Abstract: During the progressive phase of the seasonal breeding cycle four groups of male buntings were treated with (i) Normal saline (control), (ii) Luteinizing hormone (LH), (iii) L‐Dihydroxyphenylalanine (L‐DOPA, a dopamine precursor) given 8 hr after 5‐Hydroxytryptophan (5‐HTP, serotonin) (8‐hr relationship) and (iv) LH and these neurotransmitter precursor drugs with the same temporal relationship (LH + 8 hr). The results indicate that at the end of the study, while the controls as well as the LH treated birds exhibited full breeding condition (although its degree of development was higher in the latter), the testes of birds of the “8‐hr group”; showed complete atrophy. But, the birds receiving both treatments (LH + 8 hr) were not different from the controls. The body weight responses of the birds followed the same pattern as those of testes weight. It is suggested that the phase relationship of serotonergic and dopaminergic drugs controls the reproductive (gonadal activity) and metabolic (body weight...

Effects of thyroid status on arginine vasotocin receptor VT2R expression and adrenal function in osmotically stimulated domestic fowl.

Abstract: The role of thyroid hormones in the regulation of adrenal function during stress has been documented in mammals, but only limited reports are available in avian species. The present study was undertaken to analyze the effect of hyper- or hypothyroidism on the adrenal activity under control (hydrated) and osmotically stressed (water deprived, WD) conditions, with special emphasis on the expression of arginine vasotocin receptor VT2 (VT2R) in pituitary corticotrophs. Chickens were made hyper- or hypothyroidic by injecting thyroxine (T4) and 2-thiouracil (TU), respectively for 14 days. After 10 days of injections, one sub-group of both, T4- or TU-treated chickens were subjected to osmotic stress by water deprivation. Hyperthyroidism stimulated adrenal steroidogenic activity compared to euthyroid control birds, but no change was observed in the expression of VT2R. On the other hand, TU-induced hypothyroidism however showed no effect on adrenal gland, but a significant increase in the expression of VT2R was observed. Neither hyper- nor hypothyroidism altered pro-opiomelanocortin (POMC) mRNA levels. Following osmotic stress, no effect was observed either on the adrenal gland or on the VT2R expression in hyperthyroidic birds, but in hypothyroidic birds, osmotic stress stimulated adrenal steroidogenic activity and decreased VT2R expression in comparison to its respective controls (T4 or TU). Expression of POMC mRNA was again unaltered following osmotic stress. Although exact mechanism is not clear, the data indicate that high plasma T4 level stimulates adrenal activity and may also modulate function of the pituitary-adrenal axis during dehydration.

Paraquat induced impaired reproductive function and modulation of retinal and extra-retinal photoreceptors in Japanese quail (Coturnix coturnix japonica).

Abstract: Paraquat (PQ) being a potent herbicide, causes toxic effect on growth, development and reproduction of plant as well as in animals. In this study we have mainly focused on the toxic effect of PQ on photoperception via different photoreceptors present in retina, pineal and hypothalamus and thereby its effect on hypothalamic – pituitary – gonadal (HPG) axis. PQ was administered i.p.10 mg/kg body weight daily for 1 week in poultry birds Japanese quail (Coturnix coturnix japonica). Our findings clearly indicated decrease in immunoreactivity of retinal and extra retinal photoreceptors (Iodopsin, rhodopsin and transducin) following PQ treatment in comparison to control group. Increased immunoreactivity of GnIH was observed in testis and epididymis of PQ treated group. Decreased mRNA expression of photoreceptors (rhodopsin and melanopsin), steroidogenic genes, androgen receptor, GnRH-I were found in PQ treated group while increased mRNA expression of melatonin receptors (Mel 1a R, Mel 1b R, Mel 1c R) and GnIH were found in PQ treated group. Thus, from the present results it may be concluded that PQ treatment alters the photoperception via altering the expression of photoreceptors and also modulates the HPG axis thereby alters the reproductive functions in Japanese quails.

Effect of temporal synergism of neural oscillators on gonadal development, egg production and hatchability of Japanese quail (Coturnix coturnix japonica)

Abstract: To study the effect of temporal synergism of neural oscillators (serotonergic and dopaminergic) on gonadal development, egg production and hatchability, three weeks old sexually immature Japanese quail were divided into three groups. First group quail received two daily injections of normal saline (control), second group quail received serotonin precursor (5-Hydroxytryptophan-5-HTP, 5 mg/100gm body weight) at 5.00 A.M. and dopamine precursor (L-dihydroxyphenylalanine-L-DOPA, 5mg/l00gm body weight) at 1.00 P.M. (8-hr) and third group quail received above two injections at the interval of 12 hour i.e. at 5.00 A.M. and 5.00 P.M. respectively (12-hr). Each group contained colony of male and female quail (1:2 ratio). After 11 days of treatment, given in continuous condition of light (LL), quail were transferred to long day length condition (LD 16:8) and biweekly observations were taken. The 12-hr quail showed significant increase in the rate and degree of development of cloacal gland and testicular size, whereas in 8-hr group suppression of reproductive development was seen compared to control. Female quail also showed similar trend in follicular diameter and ovarian weight. Onset of egg laying was observed by 5th week in 12-hr quail, by 7th week in control and no egg laying was noted in 8-hr quail. Moreover, rate of egg production, egg size and hatchability rate was remarkably high in 12-hr quail compared to control. It is obvious that 12-hr relation induced precocious sexual maturity and increased the rate of tertility. These observations suggest that injections of serotonergic and dopaminergic precursor drugs (5-HTP and L-DOPA) given at specific time interval had significant intluence on the maturation of neuroendocrine gonadal axis as well as rate of reproduction.

Seasonal changes in immune function.

Abstract: Winter is energetically demanding Physiological and behavioral adaptations have evolved among nontropical animals to cope with winter because thermoregulatory demands increase when food availability decreases Seasonal breeding is central within the suite of winter adaptations among small animals Presumably, reproductive inhibition during winter conserves energy at a time when the adds of producing viable young are low In addition to the well-studied seasonal cycles of mating and birth, there are also significant seasonal cycles of illness and death among many populations of mammals and birds in the field Challenging winter conditions, such as low ambient temperatures and decreased food availability, can directly induce death via hypothermia, starvation or shock In some cases, survival in demanding winter conditions puts individuals under great physiological stress, defined here as an adaptive process that results in elevated blood levels of glucocorticoids The stress of coping with energetically demanding conditions can also indirectly cause illness and death by compromising immune function Presumably, the increased blood concentrations of adrenocortical steroids in response to winter stressors compromise immune function and accelerate catabolic mechanisms in the field, although the physiological effects of elevated glucocorticoids induced by artificial stressors have been investigated primarily in the laboratory However, recurrent environmental stressors could reduce survival if they evoke persistent glucocorticoid secretion The working hypothesis of this article is that mechanisms have evolved in some animals to combat seasonal stress-induced immunocompromise as a temporal adaptation to promote survival Furthermore, we hypothesize that mechanisms have evolved that allow individuals to anticipate periods of immunologically challenging conditions, and to cope with these seasonal health-threatening conditions The primary environmental cue that permits physiological anticipation of season is the daily photoperiod; however, other environmental factors may interact with photoperiod to affect immune function and disease processes The evidence for seasonal fluctuations in lymphatic organ size, structure, immune function, and disease processes, and their possible interactions with recurrent environmental stressors, is reviewed Seasonal peaks of lymphatic organ size and structure generally occur in late autumn or early winter and seasonal minima are observed prior to the onset of breeding Although many of the field data suggest that immune function and disease processes are also enhanced during the winter, the opposite seasonal pattern is also observed in some studies We propose that compromised immune function may be observed in some populations during particularly harsh winters when stressors override the enhancement of immune function evoked by short day lengths Because so many factors covary in field studies, assessment of our proposal that photoperiod mediates seasonal changes in immune function requires laboratory studies in which only photoperiod is varied A review of the effects of photoperiod on immune function in laboratory studies reveals that exposure to short day lengths enhances immune function in every species examined Short day exposure in small mammals causes reproductive inhibition and concomitant reduction in plasma levels of prolactin and steroid hormones, as well as alterations in the temporal pattern of pineal melatonin secretion These hormones affect immune function, and influence the development of opportunistic diseases, including cancer: however, it appears that either prolactin or melatonin secretion is responsible for mediating the effects of photoperiod on immune function Taken together, day length appears to affect immune function in many species, including animals that typically do not exhibit reproductive responsiveness to day length

Gene regulation in the magnocellular hypothalamo-neurohypophysial system.

Abstract: The hypothalamo-neurohypophysial system (HNS) is the major peptidergic neurosecretory system through which the brain controls peripheral physiology. The hormones vasopressin and oxytocin released from the HNS at the neurohypophysis serve homeostatic functions of water balance and reproduction. From a physiological viewpoint, the core question on the HNS has always been, "How is the rate of hormone production controlled?" Despite a clear description of the physiology, anatomy, cell biology, and biochemistry of the HNS gained over the last 100 years, this question has remained largely unanswered. However, recently, significant progress has been made through studies of gene identity and gene expression in the magnocellular neurons (MCNs) that constitute the HNS. These are keys to mechanisms and events that exist in the HNS. This review is an inventory of what we know about genes expressed in the HNS, about the regulation of their expression in response to physiological stimuli, and about their function. Genes relevant to the central question include receptors and signal transduction components that receive and process the message that the organism is in demand of a neurohypophysial hormone. The key players in gene regulatory events, the transcription factors, deserve special attention. They do not only control rates of hormone production at the level of the gene, but also determine the molecular make-up of the cell essential for appropriate development and physiological functioning. Finally, the HNS neurons are equipped with a machinery to produce and secrete hormones in a regulated manner. With the availability of several gene transfer approaches applicable to the HNS, it is anticipated that new insights will be obtained on how the HNS is able to respond to the physiological demands for its hormones.