Year: 2008
Type: dissertation
Abstract: Several lines of evidence suggest that the amygdala is important for emotional arousal. However, whether overlapping or segregated populations of cells in the amygdala contribute to appetitive and aversive emotional arousal remains unclear. Here we test two predictions of the hypothesis that overlapping populations of cells in the amygdala contribute to appetitive and aversive emotional arousal: neuronal activity in the amygdala during appetitive and aversive arousal should tend to be similar, and the activity of cells with similar changes in activity during appetitive and aversive emotional arousal should be correlated with measures of arousal. Consistent with the hypothesis that overlapping populations of cells contribute to appetitive and aversive emotional arousal, we show that a large proportion of amygdala cells (26%) has qualitatively similar changes in activity during conditioned appetitive and aversive emotional arousal, despite the different sensory modalities of the eliciting stimuli. Furthermore, when the entire population of recorded cells is considered together, neuronal activity is more similar than expected by chance during conditioned appetitive and aversive emotional arousal. The basolateral region (BLA) and central nucleus (CeN) of the amygdala had similar proportions of "Same" cells, suggesting that overlapping populations of cells contribute to appetitive and aversive emotional arousal in both regions. Interestingly, however, the CeN had a greater proportion of cells with opposite changes in activity during the conditioned appetitive and aversive stimuli than the BLA, suggesting that neuronal activity in the CeN has a greater degree of affective specificity.We also found that a large proportion of cells in the amygdala, including over half of the "Same" cells, had activity that was correlated with blood pressure--a measure of emotional arousal that is sensitive to lesions of the amygdala in both appetitive and aversive settings.Together, our results suggest that the amygdala contributes to appetitive and aversive emotional arousal through the recruitment of overlapping populations of cells that respond similarly to appetitive and aversive stimuli.
Author: Steven J. Shabel
Language: English
Topic: Memory and Neural Mechanisms
Subfield: Cognitive Neuroscience
Field: Neuroscience
Domain: Life Sciences
Open Access status: green
Award: G11283329
OpenAlex ID: W31697343