Figure 2.

Anti-CE antibody enhances BAS–CA1 IPSPs and mechanisms of CE-induced transformation of GABAergic synapses. Anti-CE antibody injection into a recorded CA1 pyramidal cell enhances BAS–CA1 IPSP (a, as compared with unmarked IPSP before injection) and elicits a shift of the PSP–MP curve to the left (c). Injection of heat-inactivated antibody is ineffective (b; two traces overlapping). Average responses of BAS–CA1 PSP after injection of either anti-CE antibody (Anti-CE) or its heat-inactivated form (Control) are shown in d. Schematic drawing (e) shows mechanisms of CE-mediated transformation of GABAergic synapses. Synapse-transforming signals (such as associative activation of cholinergic and GABAergic inputs) turn on a CE/CE-like protein signal cascade. CE binds to the RyR and causes Ca²⁺ release. The Ca²⁺/CE transforms the GABAergic synapses by shifting the GABA_A reversal potential from Cl⁻ reversal potential toward HCO₃⁻ reversal potential, through altering anion selectivity of the Cl⁻ channels, activity of CA, and/or formation of HCO₃⁻. Multiple arrows indicate possible involvement of unidentified mediators. AA, arachidonic acid; DAG, diacylglycerol; ER, endoplasmic reticulum; PKC, protein kinase C.