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Published on: September 5, 2015
Cortical neurones exhibiting kainate-activated Co2+ uptake are selectively vulnerable to AMPA/kainate
D M Turetsky1, L M Canzoniero, S L Sensi
1Department of Neurology and Center for the Study of Nervous System Injury, Washington University School of Medicine, St Louis, Missouri, 63110, USA.
Abstract:
Kainate-activated Co2+ uptake, a histochemical method that identifies cells bearing Ca2+-permeable AMPA/kainate receptors, labels approximately 15% of murine cortical neurones in cell culture. While exposure times exceeding several hours were needed for AMPA or kainate to destroy most cultured cortical neurones, the subpopulation exhibiting kainate-activated Co2+ uptake was selectively destroyed after AMPA or kainate exposures of only 10-60 min. No selective loss was seen after exposure to NMDA. Kainate toxicity on Co2+ uptake-positive neurones was dependent on extracellular Ca2+ concentration, and associated with an increase in intracellular free Ca2+ even in the absence of extracellular Na+. These results suggest that a distinct subpopulation of cortical neurones expresses AMPA/kainate receptors linked to Ca2+-permeable channels, and that this characteristic conveys enhanced vulnerability to kainate-induced, Ca2+-mediated, damage.
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