Intervention of the lateral and central amygdala on the association of visual stimuli with different magnitudes of reinforcement.
Male rats received either kainic acid (KA) or sham lesions bilaterally into the lateral and central amygdala or were assigned to an unoperated control group. After the postoperation recovery period all lesioned and unoperated animals were tested for the ability to master a visual-stimulus/magnitude-of-reinforcement discrimination. Retention of the discrimination learning was evaluated 24 h later for the original and reversal problems. The lateral and central amygdala lesions differently affected the acquisition of a visual-stimulus/magnitude-of-reinforcement discrimination and did not impair its retention. The lateral amygdala-lesioned group showed a significantly poorer performance in discrimination learning than all the other groups. Its performance was even poorer than that of the central amygdala-lesioned group. The contribution of lateral and central amygdala in the major components of a visual-stimulus/magnitude-of-reinforcement discrimination is discussed. In order to know how the amygdala is involved in the association of sensorial stimuli with reinforcement, we suggest that the specific contribution of its individual nuclei in the detailed components of such an association be studied.
Peinado-Manzano
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Departamento de Psicología, Facultad de Filosofía y Ciencias de la Educaión, Universidad de Salamanca, Spain.
D000679:Amygdala / Q000502:physiology*; D000818:Animals; D001143:Arousal / Q000502:physiology; D001245:Association Learning / Q000502:physiology*; D001931:Brain Mapping; D004193:Discrimination Learning / Q000502:physiology*; D004292:Dominance, Cerebral / Q000502:physiology; D007858:Learning / Q000502:physiology*; D008297:Male; D009042:Motivation / Q000502:physiology*; D009949:Orientation / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D012193:Reversal Learning / Q000502:physiology