Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2001-2-22
pubmed:abstractText
The electrophysiological characteristics of unmodified, postnatal gonadotropin-releasing hormone (GnRH) neurons in the female mouse were studied using whole-cell recordings and single-cell RT-PCR methodology. The GnRH neurons of adult animals fired action potentials and exhibited distinguishable voltage-current relationships in response to hyperpolarizing and depolarizing current injections. On the basis of their patterns of inward rectification, rebound depolarization, and ability to fire repetitively, GnRH neurons in intact adult females were categorized into four cell types (type I, 48%; type II, 36%; type III, 11%; type IV, 5%). The GnRH neurons of juvenile animals (15-22 d) exhibited passive membrane properties similar to those of adult GnRH neurons, although only type I (61%) and type II (7%) cells were encountered, in addition to a group of "silent-type" GnRH neurons (32%) that were unable to fire action potentials. A massive, action potential-independent tonic GABA input, signaling through the GABA(A) receptor, was present at all ages. Afterdepolarization and afterhyperpolarization potentials (AHPs) were observed after single action potentials in subpopulations of each GnRH neuron type. Tetrodotoxin (TTX)-independent calcium spikes, as well as AHPs, were encountered more frequently in juvenile GnRH neurons compared with adults. These observations demonstrate the existence of multiple layers of functional heterogeneity in the firing properties of GnRH neurons. Together with pharmacological experiments, these findings suggest that potassium and calcium channels are expressed in a differential manner within the GnRH phenotype. This heterogeneity occurs in a development-specific manner and may underlie the functional maturation and diversity of this unique neuronal phenotype.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1529-2401
pubmed:author
pubmed:issnType
Electronic
pubmed:day
1
pubmed:volume
21
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1067-75
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:11157093-Action Potentials, pubmed-meshheading:11157093-Aging, pubmed-meshheading:11157093-Animals, pubmed-meshheading:11157093-Barium, pubmed-meshheading:11157093-Calcium Channels, pubmed-meshheading:11157093-Calcium Signaling, pubmed-meshheading:11157093-Cell Membrane, pubmed-meshheading:11157093-Cesium, pubmed-meshheading:11157093-Female, pubmed-meshheading:11157093-Gonadotropin-Releasing Hormone, pubmed-meshheading:11157093-Mice, pubmed-meshheading:11157093-Neurons, pubmed-meshheading:11157093-Patch-Clamp Techniques, pubmed-meshheading:11157093-Phenotype, pubmed-meshheading:11157093-Potassium Channel Blockers, pubmed-meshheading:11157093-Potassium Channels, pubmed-meshheading:11157093-Preoptic Area, pubmed-meshheading:11157093-Receptors, GABA-A, pubmed-meshheading:11157093-Reverse Transcriptase Polymerase Chain Reaction, pubmed-meshheading:11157093-Sexual Maturation, pubmed-meshheading:11157093-Tetrodotoxin, pubmed-meshheading:11157093-gamma-Aminobutyric Acid
pubmed:year
2001
pubmed:articleTitle
Heterogeneity in the basic membrane properties of postnatal gonadotropin-releasing hormone neurons in the mouse.
pubmed:affiliation
Laboratory of Neuroendocrinology, The Babraham Institute, Cambridge CB2 4AT, United Kingdom.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't