Oxytocin release in magnocellular nuclei: neurochemical mediators and functional significance during gestation.

Am J Physiol Regul Integr Comp Physiol

Dept. of Pharmacology and Toxicology, Univ. of Utah, 30 South 2000 East, Rm 201, Salt Lake City, UT 84112, USA.

Published: August 2010

When released from dendrites within the supraoptic (SON) and paraventricular (PVN) nuclei (intranuclear release) during suckling, oxytocin exerts autocrine and paracrine effects on oxytocin neurons that are necessary for the unique timing and episodic pattern of oxytocin release into the systemic circulation that is characteristic of lactation. Recent reports have shown that stimulation of central noradrenergic and histaminergic receptors are both necessary for intranuclear release of oxytocin in response to suckling. In addition, in vitro studies indicate that excitatory amino acids may also be critical for central oxytocin secretion, although in vivo experiments have not provided direct support for this hypothesis. In addition to a critical role in intranuclear oxytocin release during lactation, norepinephrine has also been shown to stimulate central oxytocin during gestation. Stimulation of central oxytocin receptors during gestation appears critical for normal systemic oxytocin secretion in responses to suckling during the subsequent period of lactation. Oxytocin receptor blockade during pregnancy alters normal timing of systemic oxytocin release during suckling and reduces milk delivery. Several adaptations occur in the central oxytocin system that are necessary for determining the unique response characteristic observed during parturition and gestation. Central oxytocin receptor stimulation during gestation has been implicated in pregnancy-related morphological changes in magnocellular oxytocin neurons, disinhibition of oxytocin neurons to GABA, and adaptations in membrane response characteristics of oxytocin neurons. In conclusion, intranuclear oxytocin release during gestation and lactation are critical for establishing, and then evoking the unique pattern of systemic oxytocin secretion in response to the suckling offspring necessary for adequate milk delivery. Furthermore, activation of central noradrenergic receptors appears to be critical for release of central oxytocin in both of these reproductive states.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3774470PMC
http://dx.doi.org/10.1152/ajpregu.00217.2010DOI Listing

Publication Analysis

Top Keywords

central oxytocin
24
oxytocin
20
oxytocin release
20
oxytocin neurons
16
oxytocin secretion
12
systemic oxytocin
12
intranuclear release
8
release suckling
8
central
8
stimulation central
8

Similar Publications

Recent studies indicate that central administration of oxytocin (OT) reduces body weight (BW) in high fat diet-induced obese (DIO) rodents by reducing energy intake and increasing energy expenditure (EE). Previous studies in our lab have shown that administration of OT into the fourth ventricle (4V; hindbrain) elicits weight loss and stimulates interscapular brown adipose tissue temperature (T) in DIO rats. We hypothesized that OT-elicited stimulation of sympathetic nervous system (SNS) activation of IBAT contributes to its ability to activate BAT and reduce BW in DIO rats.

View Article and Find Full Text PDF

Intranasal oxytocin for apathy in people with frontotemporal dementia (FOXY): a multicentre, randomised, double-blind, placebo-controlled, adaptive, crossover, phase 2a/2b superiority trial.

Lancet Neurol

February 2025

Department of Clinical Neurological Sciences, University of Western Ontario, London, ON, Canada; Department of Cognitive Neurology, St Joseph's Health Care London, London, ON, Canada. Electronic address:

Background: No treatments exist for apathy in people with frontotemporal dementia. Previously, in a randomised double-blind, placebo-controlled, dose-finding study, intranasal oxytocin administration in people with frontotemporal dementia improved apathy ratings on the Neuropsychiatric Inventory over 1 week and, in a randomised, double-blind, placebo-controlled, crossover study, a single dose of 72 IU oxytocin increased blood-oxygen-level-dependent signal in limbic brain regions. We aimed to determine whether longer treatment with oxytocin improves apathy in people with frontotemporal dementia.

View Article and Find Full Text PDF

Introduction: Around the world, rates of induction of labour (IOL) among nulliparous mothers have increased in the last 10 years. In Australia, rates have increased over the last decade by 43%, from 32% to 46%. There is growing concern about the rapid rise in IOL before 41 weeks for nulliparous women without medical complications because of the associated increased rates of caesarean section, reduced satisfaction with birth, and birth trauma.

View Article and Find Full Text PDF

Neural Plasticity in Migraine Chronification.

Eur J Neurosci

January 2025

Faculty of Medicine, Collegium Medicum, Mazovian Academy in Plock, Plock, Poland.

Chronic migraine (CM) is the ultimate and most burdensome form of the transformation from episodic migraine (EM), called chronification. The mechanism behind migraine chronification is poorly known and difficult to explore as CM has the same spectrum of pathogenesis as EM and the EM-CM transition is bidirectional. Central sensitization (CS) is a key phenomenon in migraine: its mechanisms include disturbed neural plasticity, which is the ability of the nervous system to adapt to endo- and exogenous changes.

View Article and Find Full Text PDF

Endocannabinoid contributions to the perception of socially relevant, affective touch in humans.

Neuropsychopharmacology

January 2025

Department of Biomedical and Clinical Sciences, Center for Social and Affective Neuroscience, Linköping University, Linköping, Sweden.

Social relationships are central to well-being. A subgroup of afferent nerve fibers, C-tactile (CT) afferents, are primed to respond to affective, socially relevant touch and may mitigate the effects of stress. The endocannabinoid ligand anandamide (AEA) modulates both social reward and stress.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!