Linked Life Data

8931023

Source:http://linkedlifedata.com/resource/pubmed/id/8931023

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1997-3-14
pubmed:abstractText
A spinal cord slice preparation was developed in order to study developmental changes in intrinsic membrane properties and in responses to N-methyl-D-aspartate and serotonin in embryonic chick motoneurons. Transverse spinal cord slices were obtained from chick embryos over a series of developmental stages (embryonic days 12-18). Intracellular recordings were obtained from 87 antidromically identified motoneurons. During the stages examined, the average resting membrane potential did not vary significantly, the voltage threshold of current-evoked action potentials became significantly more negative, there was a non-significant trend towards a decrease in the recorded input resistance, but there were no significant changes observed in the membrane time constant. There were significant developmental changes in the waveform of the current-evoked action potentials. The average amplitude of the action potentials increased over the stages studied, while the action potential duration measured at half-amplitude decreased. All of the motoneurons examined were maximally depolarized by bath application of 50 microM N-methyl-D-aspartate. The depolarization persisted in the presence of tetrodotoxin but was blocked by 100 microM 2-amino-5-phosphonopentanoic acid and, therefore, was at least partially due to a direct action of N-methyl-D-aspartate on motoneuronal receptors. The average amplitude of the N-methyl-D-aspartate-induced depolarizations decreased significantly over the stages examined. In contrast, bath application of 50 microM serotonin produced either depolarizing or hyperpolarizing responses depending on the developmental age of the motoneuron. Serotonin induced a depolarization in about 50% of the motoneurons at embryonic day 12, 69% of the motoneurons at embryonic day 15 and 100% of the motoneurons recorded from at embryonic day 18. These findings reveal important developmental changes in intrinsic membrane responses and action potential properties of chick motoneurons recorded from a slice preparation. We have also documented changes in the motoneuronal responses to serotonin, a neurotransmitter used by a major descending projection, and N-methyl-D-aspartate, which activates glutamate receptors known to contribute to synaptic activity in segmental circuits.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0306-4522
pubmed:author
pubmed:issnType
Print
pubmed:volume
75
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
607-18
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Developmental changes in the effects of serotonin and N-methyl-D-aspartate on intrinsic membrane properties of embryonic chick motoneurons.
pubmed:affiliation
Department of Anatomy (Slot 510), University of Arkansas for Medical Sciences, Little Rock 72205-7199, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.