Alcohol, when delivered systemically, leads to impaired performance on a variety of tasks, including emotionally-laden or reward value tasks. It is also known that lesions to the amygdala produce emotional or reward value deficits. However, it is unknown whether the emotional deficits observed after alcohol ingestion are due to alcohol's direct effect on the amygdala. The present study examined the effects of alcohol when infused directly into the amygdala on emotional memory and judgment. Eight male Long-Evans rats were trained on a behavioral task to associate one sweetness level with a reward and another sweetness level with no reward. Once the rats learned to discriminate between reward and no reward stimuli, they underwent surgery to implant guide cannulae to directly infuse alcohol into the amygdala. After a week recovery period, rats were given bilateral infusions of a 1.0% solution of alcohol, a 0.1 % solution of alcohol, or a saline infusion. It was predicted that rats would perform more poorly on the reward value memory task following alcohol infusions into the amygdala, but that motor skills, motivation, and procedural memory would not be impaired. As predicted, motor skills, motivation and procedural memory were not impaired. However, results did not support the a priori hypothesis that intracranial infusions of alcohol into the amygdala would impair reward value memory performance, suggesting that alcohol may be affecting other brain areas involved in emotional decision making, such as the prefrontal cortex.
Brewer '05, Stephanie M., "Ethanol Effects on Reward Value Judgment Following Infusions into the Amygdala: Implications for Emotional Processing" (2005). Honors Projects. Paper 17.