Addition of quisqualate to mouse hippocampal neurons in vitro elicited two types of changes in [Ca2+](i) as assessed by fura-2-based microfluorimetry. The first was a transient spike or group of oscillations and the second was a long lasting 'plateau' response. The long-lasting response was abolished on removal of either Ca2+ or Na+ from the external medium or by blocking voltage-sensitive Ca2+ channels. Furthermore, the novel glutamate antagonist 6-nitro-7-cyano-quinoxaline-2,3-dione was competitive inhibitor of this response. In contrast, none of these manipulations abolished the transient [Ca2+](i) spike. Transient [Ca2+](i) spikes of oscillations could also be produced by the α1-adrenergic agonist phenylephrine. Production of such an α1-response reduced the size of a subsequently elicited quisqualate response. However production of transient [Ca2+](i) spikes with caffeine did not alter the size of the quisqualate-induced spike. We conclude that hippocampal neurons possess two different types of quisqualate receptors. The first mediates quisqualate-induced depolarization and the second mediates Ca2+ mobilization from intracellular stores.
|Original language||English (US)|
|Number of pages||10|
|State||Published - 1989|
ASJC Scopus subject areas
- Molecular Medicine