VOLTAGE-DEPENDENT CALCIUM AND POTASSIUM-ION CONDUCTANCES - CONTINGENCY MECHANISM FOR AN ASSOCIATIVE LEARNING-MODEL

Persistent light-induced depolarization results from Ca2+ influx across a photoreceptor membrane. The marked dependence on potential of this Ca2+ influx and a Ca2+-dependent K+ efflux accounts for enhancement of the light-induced depolarization when light is paired with rotation. A positive feedback cycle between light-induced depolarization and synaptic depolarization due to stimulus pairing can explain long-lasting behavioral changes produced by associative training but not control paradigms. The sensitivity of this Ca2+ influx to intracellular levels of adenosine 3′,5′-monophosphate suggests biochemical steps for this model of associative learning. Copyright © 1979 AAAS.