Independence of short- and long-term memory: a neural system analysis

Rats were given electrical stimulation to the midbrain reticular formation or to the hippocampus 4 seconds after they received shocks contingent on the animals' bar-press responses. They were retested for memory of the shocks 64 seconds or 24 hours after the shocks. The animals that received stimulation to the midbrain reticular formation showed amnesia at the 64-second retest and memory at the 24-hour retest. In contrast, animals that received stimulation to the hippocampus showed memory at the 64-second retest and amnesia at the 24-hour retest. The data support a dual, parallel-processing model of memory.