Biophysical mechanisms contributing to inking behavior in Aplysia

1. The release of ink from the ink gland ofAplysicr cafllf~rnica in response to noxious stimuli is mediated by three electrically coupled motor neurons, L14*, L14R, L14c, whose cell bodies are located in the abdomi-nal ganglion. The initial synaptic input to the ink motor neurons is relatively ineffective in firing the cells. As a result, a pause of l-3 s often occurs before the cells attain their maximum firing frequency and cause the re-lease of ink. Using current and voltage-clamp techniques we have analyzed the mechanisms underlying the firing pattern of these cells. 2. The presence of a fast transient K