Postnatal development of the calcium-dependency of glutamate release from rat cortical synaptosomes: comparison with 5-hydroxytryptamine release.
The ontogeny of the Ca(2+)-dependency of the depolarisation-induced release of preloaded [3H]glutamate and [3H]5-hydroxytryptamine [5-HT] from rat cortical synaptosomes was examined. 5-HT release was found to be exclusively Ca(2+)-dependent at all ages studied. In contrast, glutamate release only showed a significant Ca(2+)-dependent component from postnatal day 10 [PND 10] onwards. This correlated with the ontogeny of the glutamate accumulating activity of synaptic vesicles, a finding consistent with vesicles being the site of Ca(2+)-dependent release. The effectiveness of K(+)-depolarisation in inducing the Ca(2+)-dependent release of both transmitters increased during the early neonatal period, reaching near adult levels at PND20 for 5-HT and PND30 for glutamate.
Jennings
P
P
Physiology Unit School of Molecular and Medical Biosciences University of Wales, Cardiff, UK.
Collard
K J
KJ
D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002540:Cerebral Cortex / Q000187:drug effects* / Q000502:physiology / Q000648:ultrastructure; D018698:Glutamic Acid / Q000378:metabolism*; D008564:Membrane Potentials / Q000187:drug effects; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000378:metabolism*; D013574:Synaptosomes / Q000187:drug effects* / Q000378:metabolism
D012701:Serotonin; D018698:Glutamic Acid; D011188:Potassium; D002118:Calcium