Changes in synaptosomal glutamate release during postnatal development in the rat hippocampus and cortex.
The effectiveness of K+ depolarisation in inducing the release of [3H]L-glutamate from preloaded hippocampal and cortical synaptosomes was examined in rats aged from postnatal day 4 (PND 4) to adult. In the lower age groups studied (PND 4-PND 15), the response to depolarisation was always smaller than that seen in the adult. From PND 15, the sensitivity of the release process increased steadily to a maximum level in the adult. The relatively small amounts of glutamate released in response to K(+)-depolarisation in the younger age groups may be a factor which contributes to the relative insensitivity of neonatal brain to ischaemic damage. Discrete variations in the sensitivity to K+ depolarisation observed in animals aged from PND 4 to PND 15 may be involved in plastic changes in neural activity which are known to occur during this important development period.
Collard
K J
KJ
Department of Physiology, University of Wales, College of Cardiff, UK.
Edwards
R
R
Liu
Y
Y
D000375:Aging / Q000502:physiology*; D000818:Animals; D000831:Animals, Newborn; D001692:Biological Transport; D002540:Cerebral Cortex / Q000254:growth & development / Q000378:metabolism*; D005971:Glutamates / Q000378:metabolism*; D018698:Glutamic Acid; D006624:Hippocampus / Q000254:growth & development / Q000378:metabolism*; D008564:Membrane Potentials / Q000187:drug effects; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000378:metabolism; D012964:Sodium / Q000494:pharmacology; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism*
D005971:Glutamates; D012701:Serotonin; D018698:Glutamic Acid; D012964:Sodium; D011188:Potassium