Facilitation of learning in adult and aged rats following bilateral lesions of the tuberomammillary nucleus region.
In the present experiment, adult (3-month-old) and aged (31-month-old) rats received bilateral DC or sham-lesions in the region of the tuberomammillary (TM) nucleus before they were trained and tested on a one-trial step-through inhibitory avoidance task. Bilateral lesions of the TM nucleus led to significantly longer latencies in the step-through response during retention test in both adult and aged rats, indicative of superior learning of the task. Thus, lesions of the TM nucleus may have a facilitatory effect on learning and mnemonic functioning which is possibly related to a lesion-induced disinhibition or facilitation of reinforcement processes ("stamping-in") as revealed in previous studies.
Klapdor
K
K
Institute of Physiological Psychology I, Heinrich-Heine-University of Düsseldorf, Germany.
Hasenöhrl
R U
RU
Huston
J P
JP
D000375:Aging / Q000502:physiology*; D000818:Animals; D001362:Avoidance Learning / Q000502:physiology*; D004292:Dominance, Cerebral / Q000502:physiology*; D004597:Electroshock; D007034:Hypothalamus, Posterior / Q000502:physiology*; D008297:Male; D008326:Mammillary Bodies / Q000502:physiology*; D011939:Mental Recall / Q000502:physiology*; D009042:Motivation; D010865:Pilot Projects; D051381:Rats; D011930:Reaction Time / Q000502:physiology; D012153:Retention, Psychology / Q000502:physiology*