Fig. 7.

Group data showing the mean spike frequency during a 10 sec depolarizing current step at different time periods recorded from lateral type A photoreceptors of conditioned (•Conditioned PKC(19–36); n = 8) and pseudorandom controls (○ Pseudorandom Control PKC(19–36); n = 10) that were impaled with electrodes containing the PKC inhibitor PKC(19–36). A separate paired group (n = 5) received the inactive form of the inhibitor [▵ Conditioned[glu²⁷](19–36)]. The initial current step (6 min) elicited significantly more action potentials from lateral type A photoreceptors of conditioned animals (•, ▵) compared with pseudorandom controls (○). Excitability in the conditioned group that received the active form of the inhibitor (•), however, was reduced significantly over time. Excitability of the lateral type A photoreceptors from the conditioned group was not different significantly from pseudorandom controls at 16, 26, 36, or 46 min. The conditioned group that received the inactive form of the inhibitor (▵) exhibited enhanced excitability over the entire 46 min period of recording.