Tuberomammillary nucleus lesion facilitates two-way active avoidance retention in rats.
To evaluate whether the tuberomammillary nucleus might be involved in the acquisition and/or retention of a two-way active avoidance conditioning, rats were given a unilateral lesion of the tuberomammillary nucleus (E2 region) 24 h prior to the first conditioning session. Four learning sessions were performed: one acquisition and 3 retention sessions (short-term, 24 h; and long-term, 8 and 18 days). Results showed that the lesion facilitated the long-term retention of conditioning, but no effects were observed on acquisition and short-term retention. Since rewarding intracranial electrical stimulation seems to be a consistent way to facilitate learning and memory processes, and tuberomammillary lesion has been shown to improve intracranial self-stimulation behavior (ICSS), we suggest that lesions in the present experiment could have facilitated two-way active avoidance retention by enhancing the function of brain reward mechanisms.
Segura-Torres
P
P
Departament de Psicobiologia i Metodologia en Ciències de la Salut Universitat Autonoma de Barcelona, Spain.
Wagner
U
U
Massanes-Rotger
E
E
Aldavert-Vera
L
L
Marti-Nicolovius
M
M
Morgado-Bernal
I
I
D000818:Animals; D001362:Avoidance Learning / Q000502:physiology*; D001835:Body Weight / Q000502:physiology; D004567:Electrodes, Implanted; D008297:Male; D008326:Mammillary Bodies / Q000502:physiology*; D008570:Memory, Short-Term / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D012153:Retention, Psychology / Q000502:physiology*; D012653:Self Stimulation