Two different properties of short- and long-term memory.
Rats were trained in one-trial step-down inhibitory avoidance and tested 1.5-9 h later or 1-4 days later in order to evaluate short- and long-term memory respectively. No extinction was observed when the animals were tested repeatedly at 1.5, 3, 4.5 and 6 h; when they were tested repeatedly at 9, 24, 48, 72 and 96 h, there was partial extinction. Exposure to an open field for 2 min, 1 h after training did not affect retention scores of animals tested at 1.5 or 3 h, had a slight amnestic effect on groups tested at 4.5 or 6 h, and markedly reduced retention scores in animals tested at 9 or 24 h from training. Thus, there were two clear behavioural differences between memory measured in the first few hours or in the following few days, which suggests that both involve different mechanisms.
Medina
J H
JH
Instituto de Biologia Celular y Neurociencia Eduardo de Robertis, Facultad de Medicina, Universidad de Buenos Aires, Argentina.
Schröder
N
N
Izquierdo
I
I
D000647:Amnesia / Q000523:psychology; D000818:Animals; D001362:Avoidance Learning; D004777:Environment; D005108:Extinction, Psychological; D008568:Memory / Q000502:physiology*; D008570:Memory, Short-Term / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors