Within-event learning in rats with lesions of the basolateral amygdala

• Published in: Behavioural brain research 2013-01, Vol.236 (1), p.48-55
• Main Authors: Blundell, Pam, Symonds, Michelle, Hall, Geoffrey, Killcross, Simon, Bailey, Glynis. K.
• Format: Article
• Language: English
• Subjects: Amygdala; Amygdala - anatomy & histology; Amygdala - injuries; Amygdala - physiology; Animals; Aversion learning; Avoidance Learning - physiology; Basolateral amygdala; Behavioral psychophysiology; Biological and medical sciences; Conditioning, Operant - physiology; Fundamental and applied biological sciences. Psychology; Learning; Learning - physiology; Male; Neurotoxicity; Neurotoxicity Syndromes - psychology; Neurotoxins; Odor; Odor aversion learning; Odorants; Prunus; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Psychomotor Performance - physiology; Quinolinic Acid; Rats; Smell - physiology; Taste; Taste - physiology; Vanilla
• ISSN: 0166-4328; 1872-7549
• DOI: 10.1016/j.bbr.2012.08.030

▸ We examine BLA- and sham-lesioned rats’ ability to form sensory–sensory associations. ▸ BLA-lesioned rats can acquire sensory preconditioning. ▸ BLA-lesioned rats are impaired at taste-potentiated odor aversion. ▸ BLA needed for learning sensory properties of motivationally significant stimuli. Rats with neurotoxic lesions of the basolateral amygdala were trained in procedures designed to assess the formation of within-event, taste–odor associations. In Experiments 1 and 2 the animals were given initial exposure to a taste–odor compound; the value of the taste was then modified, and the consequent change in responding to the odor was taken to indicate that an odor–taste association had been formed. In Experiment 1 the value of the taste (saline) was enhanced by means of salt-depletion procedure; in Experiment 2 the taste was devalued by aversive conditioning. In neither procedure did lesioned animals differ from sham-operated controls. Experiment 3 confirmed, however, that taste-potentiation of odor aversion learning (an effect thought to depend on the formation of a taste–odor association) is abolished by the lesion. Implications for the view that the amygdala is necessary for sensory–sensory associations between events in different modalities are considered.