Food consumption impacts body weight differently depending on the time of day. Here, we investigated whether suprachiasmatic nucleus (SCN) neurons responsive to the hormone ghrelin temporally regulate eating and body weight in mice. The chemogenetic stimulation of GHSR (growth hormone secretagogue receptor)-expressing SCN neurons during the mid-rest phase-when mice are most sensitive to ghrelin's orexigenic effects-increased food intake.
View Article and Find Full Text PDFNeuropeptide cocaine- and amphetamine-regulated transcript (CART) is widely expressed in the brains of teleosts, amphibians, birds, and mammals and has emerged as a conserved regulator of energy balance across these vertebrate phyla. However, as yet, there is no information on CART in the reptilian brain. We characterized the cDNA encoding CART and mapped CART-containing elements in the brain of gecko, Hemidactylus leschenaultii (hl) using a specific anti-CART antiserum.
View Article and Find Full Text PDFEndocrinology
September 2024
Objective: The number of individuals affected by metabolic dysfunction associated fatty liver disease [1] is on the rise, yet hormonal contributors to the condition remain incompletely described and only a single FDA-approved treatment is available. Some studies suggest that the hormones ghrelin and LEAP2, which act as agonist and antagonist/inverse agonist, respectively, for the G protein coupled receptor GHSR, may influence the development of MAFLD. For instance, ghrelin increases hepatic fat whereas synthetic GHSR antagonists do the opposite.
View Article and Find Full Text PDFReducing ghrelin by ghrelin gene knockout (GKO), ghrelin-cell ablation, or high-fat diet feeding increases islet size and β-cell mass in male mice. Here we determined if reducing ghrelin also enlarges islets in females and if pregnancy-associated changes in islet size are related to reduced ghrelin. Islet size and β-cell mass were larger (P = .
View Article and Find Full Text PDFDespite the growing popular interest in sleep and diet, many gaps exist in our scientific understanding of the interaction between circadian rhythms and metabolism. In this Review, we explore a promising, bidirectional role for ghrelin in mediating this interaction. Ghrelin both influences and is influenced by central and peripheral circadian systems.
View Article and Find Full Text PDFGhrelin exerts key effects on islet hormone secretion to regulate blood glucose levels. Here, we sought to determine whether ghrelin's effects on islets extend to the alteration of islet size and β cell mass. We demonstrate that reducing ghrelin - by ghrelin gene knockout (GKO), conditional ghrelin cell ablation, or high-fat diet (HFD) feeding - was associated with increased mean islet size (up to 62%), percentage of large islets (up to 854%), and β cell cross-sectional area (up to 51%).
View Article and Find Full Text PDFPrevious studies have implicated the orexigenic hormone ghrelin as a mediator of exercise endurance and the feeding response postexercise. Specifically, plasma ghrelin levels nearly double in mice when they are subjected to an hour-long bout of high-intensity interval exercise (HIIE) using treadmills. Also, growth hormone secretagogue receptor-null (GHSR-null) mice exhibit decreased food intake following HIIE and diminished running distance (time until exhaustion) during a longer, stepwise exercise endurance protocol.
View Article and Find Full Text PDFObjective: Prader-Willi syndrome (PWS) is a multisystem genetic disorder. Unfortunately, none of several mouse models carrying PWS mutations emulates the entirety of the human PWS phenotype, including hyperphagia plus obesity.
Methods: To determine whether housing at thermoneutrality (TN, 30 °C) permits the development of hyperphagia and obesity in the Snord116del PWS mouse model, the effects of housing three different ages of Snord116del and wild-type (WT) littermates at TN versus room temperature (RT, 22-24 °C) for 8 weeks were compared.
Endocrinology
January 2023
In contrast to mammals, birds have a higher basal metabolic rate and undertake wide range of energy-demanding activities. As a consequence, food deprivation for birds, even for a short period, poses major energy challenge. The energy-regulating hypothalamic homeostatic mechanisms, although extensively studied in mammals, are far from clear in the case of birds.
View Article and Find Full Text PDFCalcium-binding proteins (CBPs) regulate neuronal function in midbrain dopamine (DA)-ergic neurons in mammals by buffering and sensing the intracellular Ca , and vesicular release. In birds, the equivalent set of neurons are important in song learning, directed singing, courtship, and energy balance, yet the status of CBPs in these neurons is unknown. Herein, for the first time, we probe the nature of CBPs, namely, Calbindin-, Calretinin-, Parvalbumin-, and Secretagogin-expressing DA neurons in the ventral tegmental area (VTA) and substantia nigra (SN) in the midbrain of zebra finch, Taeniopygia guttata.
View Article and Find Full Text PDFSecretagogin (scgn), is a novel hexa EF-hand, phylogenetically conserved calcium-binding protein. It serves as Ca sensor and participates in Ca -signaling and neuroendocrine regulation in mammals. However, its relevance in the brain of non-mammalian vertebrates has largely remained unexplored.
View Article and Find Full Text PDFObjective: The hormone liver-expressed antimicrobial peptide-2 (LEAP2) is a recently identified antagonist and an inverse agonist of the growth hormone secretagogue receptor (GHSR). GHSR's other well-known endogenous ligand, acyl-ghrelin, increases food intake, body weight, and GH secretion and is lowered in obesity but elevated upon fasting. In contrast, LEAP2 reduces acyl-ghrelin-induced food intake and GH secretion and is found elevated in obesity but lowered upon fasting.
View Article and Find Full Text PDFThe mesolimbic dopamine (DA)-pathway regulates food-reward, feeding-related behaviour and energy balance. Evidence underscores the importance of feeding-related neuropeptides in modulating activity of these DA neurons. The neuropeptide, CART, a crucial regulator of energy balance, modulates DA-release, and influences the activity of ventral tegmental area (VTA) DAergic neurons in the mammalian brain.
View Article and Find Full Text PDFObjective: Acyl-ghrelin regulates eating, body weight, blood glucose, and GH secretion upon binding to its receptor GHSR (growth hormone secretagogue receptor; ghrelin receptor). GHSR is distributed in several brain regions and some peripheral cell-types including pituitary somatotrophs. The objective of the current study was to determine the functional significance of acyl-ghrelin's action on GHSR-expressing somatotrophs in mediating GH secretion and several of acyl-ghrelin's metabolic actions.
View Article and Find Full Text PDFIndian J Psychiatry
October 2020
Background: No information is available about the impact of lockdown and COVID-19 pandemic on the mental health services in the private practice in India.
Aim: The current study is aimed to assess the impact of the COVID-19 pandemic and lockdown on the state of Mental Health Services in the Private Sector in India.
Materials And Methods: An online survey was carried out using the Survey Monkey platform during the period of 1 to 15 May 2020 among the members of the Indian Psychiatric Society.
Background: There is some information from different developed coutries that mental health services have been badly affected by the COVID-19 pandemic. Little information is available from India.
Aim: The aim of this study was to evaluate the impact of lockdown and COVID-19 pandemic on mental health services in India's various training centers.
This study tested the hypothesis whether hypothalamic cocaine-and amphetamine-regulated transcript (CART)-containing systems were involved in photoperiod-induced responses associated with spring migration (hyperphagia and weight gain) and reproduction (gonadal maturation) in migratory songbirds. We specifically chose CART to examine neural mechanism(s) underlying photoperiod-induced responses, since it is a potent anorectic neuropeptide and involved in the regulation of changes in the body mass and reproduction in mammals. We first studied the distribution of CART-immunoreactivity in the hypothalamus of migratory redheaded buntings (Emberiza bruniceps).
View Article and Find Full Text PDFExposure of NMDA receptor antagonists during developmental stages leads to behavioral consequences like attention deficit hyperactivity disorder (ADHD). However, the underlying molecular mechanisms have remained poorly understood. Herein, we studied the phosphorylated Akt (pAkt) and caspase-3, the key regulators of neuronal cell survival/death, as the probable downstream targets of MK-801 often used to engender ADHD-like condition.
View Article and Find Full Text PDFThermosensitive transient receptor potential vanilloid (TRPV) channels are widely expressed in the brain and known to profoundly influence Ca-signaling, neurotransmitter release and behavior. While these channels are expressed in the cerebellum, neuronal firing and hyperactivity/reflexes seem associated with cerebellar temperature modulation. However, the distribution and functional significance of TRPV-equipped elements in the cerebellum has remained unexplored.
View Article and Find Full Text PDFThyrotropin-releasing hormone (TRH) regulates the hypothalamic-pituitary-thyroid axis in mammals and also regulates prolactin secretion, directly or indirectly via tuberoinfundibular dopamine neurons. Although TRH is abundantly expressed in teleost brain and believed to mediate neuronal communication, empirical evidence is lacking. We analyzed pro-TRH-mRNA expression, mapped TRH-immunoreactive elements in the brain and pituitary, and explored its role in regulation of hypophysiotropic dopamine (DA) neurons in the catfish, Clarias batrachus.
View Article and Find Full Text PDFIn recent years estradiol has emerged as a potential regulator of transient receptor potential vanilloid (TRPV) cationic channels in the peripheral tissues and sensory neurons, however, its analogous role in the CNS is poorly understood. TRPV channels modulate Ca signalling, neurotransmission and behaviour, and expression of these ion channels and estrogen receptors show a great degree of overlap in different brain regions. Herein, we probe if Trpv1-6 genes contain estrogen receptor-binding sites and if their expression in different brain regions is modulated during estrous cycle.
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