Thursday, July 20, 2006

The Locus Ceruleus Is Involved in the Retrieval of Emotional Memories in Humans

Emotional events are usually remembered better than neutral ones, and the amygdala is involved in this enhancement. The level of the amygdala's response during encoding of either emotional events or neutral stimuli encoded in an emotional contex is related to the ease of subsequent recall. Retrieving such memories is accompanied by significant amygdalar responses. Sterpenich et. al. have now shown that successful recognition of stimuli encoded in emotional context is accompanied by a significant response not only in the amygdala and parahippocampal gyrus but also in central arousing structures of the brainstem and the diencephalon (centered on the locus ceruleus). They found that locus ceruleus responses at retrieval, as a constituent element of the emotional memory, could be related to the arousal induced during encoding.

A Right amygdala. C Parahippocampus gyrus

A. Locus ceruleus.
Credit: J. Neuroscience

1 comment:

  1. Hello Deric--thanks for your ongoing, interesting posts!

    About the locus coerulus, my understanding of earlier work is that it also participates in a circuit, with the hippocampus, (which inhibits it until novelty is detected), so that it doses the entire cortex with norepinephrine when something new is encountered by the hippocampus, enhancing the probability of learning that new thing and all its associated context for 2 to 10 seconds. I've always that this was the mechanism of "teachable moments" and language learning in infants and young children--and now the importance of emotional activation of learning is underscored by these new results. There is behavioral data (Risley & Hart) that even a small amount (e.g. 8% of communicative interactions) of punitive, negative affect in parental communications is disproportionately connected with slower rates of language learning--presumably the amygdala circuitry is involved here too.

    cheers, Robin