Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

Tuberoinfundibular dopamine (TIDA) neurons are the central regulators of prolactin (PRL) secretion. Their extensive functional plasticity allows a change from low PRL secretion in the non-pregnant state to the condition of hyperprolactinemia that characterizes lactation. To allow this rise in PRL, TIDA neurons are thought to become unresponsive to PRL at lactation and functionally silenced. Here we show that, contrary to expectations, the electrical properties of the system were not modified during lactation and that the neurons remained electrically responsive to a PRL stimulus, with PRL inducing an acute increase in their firing rate during lactation that was identical to that seen in non-pregnant mice. Furthermore, we show a long-term organization of TIDA neuron electrical activity with an harmonization of their firing rates, which remains intact during lactation. However, PRL-induced secretion of dopamine (DA) at the median eminence was strongly blunted during lactation, at least in part attributable to lack of phosphorylation of tyrosine hydroxylase, the key enzyme involved in DA synthesis. We therefore conclude that lactation, rather than involving electrical silencing of TIDA neurons, represents a condition of decoupling between electrical activity at the cell body and DA secretion at the median eminence.

Original publication

DOI

10.1523/JNEUROSCI.4415-12.2013

Type

Journal article

Journal

J Neurosci

Publication Date

2013

Volume

33

Pages

4424 - 4433

Keywords

Action Potentials/drug effects/genetics/*physiology Analysis of Variance Animals Bacterial Proteins/genetics/metabolism Benz(a)Anthracenes/pharmacology Biophysics Dopamine/metabolism Dopamine Plasma Membrane Transport Proteins/genetics Dopaminergic Neurons/*physiology Electric Stimulation Female Hypothalamic Area, Lateral/*cytology In Vitro Techniques Lactation/drug effects/genetics/*physiology Luminescent Proteins/genetics/metabolism Male Mice Mice, Transgenic Neuronal Plasticity/genetics/*physiology Patch-Clamp Techniques Prolactin/metabolism/pharmacology Proteins/genetics/metabolism RNA, Untranslated Radioimmunoassay Vesicular Monoamine Transport Proteins/genetics/metabolism