Short-term memory, exploration and locomotor activity in aged rats.
Behavioral profiles of young (3-6 months) and aged (24-27 months) rats were compared in three respects: (1) short-term memory, (2) exploration and (3) locomotor activity. Compared to young rats, aged rats were impaired in the 8-arm radial maze acquisition, but not in the delayed reinforced alternation acquisition. They had lower scores of spontaneous alternation, of exploration of a novel object and of a novel environment. Their exploratory activity was lower in a simple environment but similar in a complex environment. Their spontaneous locomotor activity was lower during the dark part of the cycle (8 p.m.-8 a.m.) but not different during the light part of the cycle (8 a.m.-8 p.m.). These results suggest that with respect to short-term memory and exploration, differences between aged and young rats may be influenced by a "complexity" factor and may be secondary to differences in motivation and reactions to novelty.
Willig
F
F
Laboratoire de Psychophysiologie, Universite Paris 7, France.
Palacios
A
A
Monmaur
P
P
M'Harzi
M
M
Laurent
J
J
Delacour
J
J
D000375:Aging / Q000523:psychology*; D000818:Animals; D003213:Conditioning, Psychological / Q000502:physiology; D005106:Exploratory Behavior / Q000502:physiology*; D006185:Habituation, Psychophysiologic / Q000502:physiology; D007858:Learning / Q000502:physiology; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D009043:Motor Activity / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains