Multiple memory processes following training that a food is inedible in Aplysia.
In many organisms, memory after training can be separated into a number of processes. We now report that separable memory processes are also initiated by a training procedure affecting Aplysia feeding behavior, a model system for examining the neural mechanisms underlying the regulation of a complex behavior. Four distinct memory process were identified: (1) a very short-term memory that declines within 15 min, (2) a short-term memory that persists for 0.5-1.0 hr, (3) an intermediate-term memory, observed 4 hr after training, and (4) a long-term memory that is seen only after a 12- to 24-hr delay. The four memory processes can be distinguished by the different training procedures that are required to elicit them. A single 5-min training session is sufficient to elicit the very short-term memory. However, a longer training session that continues until the animal stops responding to food is needed to elicit short-term memory. Intermediate-term memory is observed only after a spaced training procedure (three 5-min training sessions separated by 30-min intervals). A single 5-min training session that does not cause either short-term or intermediate-term memory is sufficient to induce long-term memory, indicating that short- and long-term memory are independent, parallel processes. Short- and long-term memory can also be separated by the effects of a post-training experience. Long-term, but not short-term, memory can be attenuated by cooling animals immediately after training. Cooling before the training does not affect either the training or the subsequent short- or long-term memory.
Botzer
D
D
Department of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel.
Markovich
S
S
Susswein
A J
AJ
D000818:Animals; D001048:Aplysia / Q000502:physiology*; D003216:Conditioning, Operant / Q000502:physiology; D005247:Feeding Behavior / Q000502:physiology; D008568:Memory / Q000502:physiology; D008570:Memory, Short-Term / Q000502:physiology