Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
2000-10-19
pubmed:abstractText
It is well established that GABAA-mediated postsynaptic potentials are excitatory in many brain regions during embryonic and early postnatal life. The pre-Bötzinger complex (PBC) in the brainstem is an essential component of the respiratory rhythm-generating network, where GABAA-mediated inhibition plays a critical role in generating a stable respiratory rhythm in adult animals. In the present study, using the perforated patch technique, we investigated the maturation of GABAA receptor-mediated effects on rhythmically active PBC neurons and on the motor output in slice preparations from P0-15 neonatal mice. The reversal potential of GABAA receptor-mediated current (EGABA-A) switched from depolarizing to hyperpolarizing within the first postnatal week. EGABA-A was -13.7 +/- 9.8 mV at P0, then it changed to -44.8 +/- 7.0 mV at P2 and -71.5 +/- 6.8 mV at P4. Perfusion of bicarbonate-free saline has no detectable influence on EGABA-A, indicating that a lack of Cl- extrusion during P0-3 is mainly responsible for early GABAA-ergic excitation. At the network level, blockade of GABAA receptors with bicuculline did not significantly change the frequency of rhythmic bursts recorded from hypoglossal nerve roots before P3, whereas it increased the coefficient of variation. After P3, bicuculline increased burst frequency with little effect on the coefficient of variation. Thus, chloride-mediated inhibition, which appears in PBC neurons after P3, coincides with the appearance of GABAA-mediated modulation of the respiratory rhythm. GABAA receptor-activated inhibition may therefore be necessary for frequency modulation in the respiratory network beginning on the fourth postnatal day in the mouse brainstem.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0953-816X
pubmed:author
pubmed:issnType
Print
pubmed:volume
12
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2975-84
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Early postnatal maturation of GABAA-mediated inhibition in the brainstem respiratory rhythm-generating network of the mouse.
pubmed:affiliation
Centre of Physiology and Pathophysiology, University of Göttingen, 37073 Göttingen, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't