Developmental changes in arachidonic acid potentiation of NMDA currents in cortical neurones

Developmental changes in the effects of arachidonic acid (AA) on N-methyl-D-aspartate (NMDA) receptor-mediated currents were investigated in acutely dissociated rat cortical neurones using a whole-cell patch-clamp method. AA potentiated peak NMDA currents (INMDA) in a concentration-dependent manner. Potentiation by AA was greater at 2-4 postnatal days (P2-4) than at P7-8 and P15-18. Indomethacin reduced the potentiating effect of AA only at P2-4, while caffeic acid and baicalein showed no apparent effect, indicating that metabolites of the cyclooxygenase pathway contribute to INMDA potentiation at P2-4. Staurosporine diminished the potentiation of INMDA at P2-4, suggesting that protein kinase C might participate in the effect of AA. These findings suggest that the greater potentiation of INMDA by AA at P2-4 has a different underlying mechanism from effects seen at P7-8 or older.