Hypothalamic molecular correlates of photoperiod-induced spring migration in intact and castrated male redheaded buntings

Sharma, Aakansha; Tripathi, Vatsala; Kumar, Vinod

doi:10.1016/j.mce.2022.111829

Cited by 2 publications

(2 citation statements)

References 63 publications

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“…We used tyrosine hydroxylase, the rate-limiting enzyme for the synthesis of dopamine, as a proxy to examine long-term changes in prolactin regulation. Th expression was significantly elevated in short-day photoperiod hamsters, consistent with studies in seasonally breeding animals including sheep ( 55 ), golden hamster ( 56 ), and redheaded buntings ( 57 ). Somatostatin is another neuropeptide that exerts inhibitory effects on prolactin secretion in mammals ( 27 ).…”

Section: Discussionsupporting

confidence: 83%

Prolactin Mediates Long-Term, Seasonal Rheostatic Regulation of Body Mass in Female Mammals

Marshall,

Blake,

Stewart

et al. 2024

Endocrinology

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A series of well-described anabolic and catabolic neuropeptides are known to provide short-term, homeostatic control of energy balance. The mechanisms that govern long-term, rheostatic control of regulated changes in energy balance are less well characterized. Using the robust and repeatable seasonal changes in body mass observed in Siberian hamsters, this report examined the role of prolactin in providing long-term rheostatic control of body mass and photoinduced changes in organ mass (ie, kidney, brown adipose tissue, uterine, and spleen). Endogenous circannual interval timing was observed after 4 months in a short photoperiod, indicated by a significant increase in body mass and prolactin mRNA expression in the pituitary gland. There was an inverse relationship between body mass and the expression of somatostatin (Sst) and cocaine- and amphetamine-regulated transcript (Cart). Pharmacological inhibition of prolactin release (via bromocriptine injection), reduced body mass of animals maintained in long photoperiods to winter–short photoperiod levels and was associated with a significant increase in hypothalamic Cart expression. Administration of ovine prolactin significantly increased body mass 24 hours after a single injection and the effect persisted after 3 consecutive daily injections. The data indicate that prolactin has pleiotropic effects on homeostatic sensors of energy balance (ie, Cart) and physiological effectors (ie, kidney, BAT). We propose that prolactin release from the pituitary gland acts as an output signal of the hypothalamic rheostat controller to regulate adaptive changes in body mass.

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Section: Discussionsupporting

confidence: 83%

Prolactin Mediates Long-Term, Seasonal Rheostatic Regulation of Body Mass in Female Mammals

Marshall,

Blake,

Stewart

et al. 2024

Endocrinology

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“…The Th gene encodes for tyrosine hydroxylase, which is the rate-limiting enzyme of the dopamine biosynthesis pathway. The reduced Th mRNA levels in castrates, compared to intact buntings, further supports this [89]. Interestingly, the expression of Th is modulated by the light quality and temperature suggesting a functional interaction of the hypothalamic thermosensitive and photoreceptive cells with dopaminergic neurons [67,90].…”

Section: Genes Associated With Dopamine Biosynthesissupporting

confidence: 58%

Genetic Control of Avian Migration: Insights from Studies in Latitudinal Passerine Migrants

Sharma

Sur

Tripathi

et al. 2023

Genes

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Twice-a-year, large-scale movement of billions of birds across latitudinal gradients is one of the most fascinating behavioral phenomena seen among animals. These seasonal voyages in autumn southwards and in spring northwards occur within a discrete time window and, as part of an overall annual itinerary, involve close interaction of the endogenous rhythm at several levels with prevailing photoperiod and temperature. The overall success of seasonal migrations thus depends on their close coupling with the other annual sub-cycles, namely those of the breeding, post-breeding recovery, molt and non-migratory periods. There are striking alterations in the daily behavior and physiology with the onset and end of the migratory period, as shown by the phase inversions in behavioral (a diurnal passerine bird becomes nocturnal and flies at night) and neural activities. Interestingly, there are also differences in the behavior, physiology and regulatory strategies between autumn and spring (vernal) migrations. Concurrent molecular changes occur in regulatory (brain) and metabolic (liver, flight muscle) tissues, as shown in the expression of genes particularly associated with 24 h timekeeping, fat accumulation and the overall metabolism. Here, we present insights into the genetic basis of migratory behavior based on studies using both candidate and global gene expression approaches in passerine migrants, with special reference to Palearctic-Indian migratory blackheaded and redheaded buntings.

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Hypothalamic molecular correlates of photoperiod-induced spring migration in intact and castrated male redheaded buntings

Cited by 2 publications

References 63 publications

Prolactin Mediates Long-Term, Seasonal Rheostatic Regulation of Body Mass in Female Mammals

Prolactin Mediates Long-Term, Seasonal Rheostatic Regulation of Body Mass in Female Mammals

Genetic Control of Avian Migration: Insights from Studies in Latitudinal Passerine Migrants

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