視床と情動

Thalamus and Emotion

視床背内側核は情動の形成に重要な基底外側辺縁回路と前頭葉-皮質下回路の一要素である。視床下部は基底外側辺縁回路と連結している。視床背内側核や視床下部が損傷すると，発現する情動に異常が生じる。視床枕は上丘-視床枕-扁桃体経路の一要素として，生態学的に重要な視覚情報の，無意識的な処理や意識的ですばやい処理に関わる。視床枕が損傷すると，視覚的脅かしや恐怖の表情が短時間だけ提示されたとき，反応に異常が生じる。

Abstract

The basolateral limbic circuit (mediodorsal thalamic nucleus, anterior cingulated and prefrontal orbital cortex, anterior temporal cortex, and amygdala), the mediodorsal thalamic nucleus circuit, and part of the frontal-subcortical circuits (anterior cingulate and prefrontal orbital cortex, caudate nucleus and nucleus accumbens, globus pallidus, and mediodorsal thalamic nucleus), and the anterior cingulate and prefrontal orbital cortex circuit are crucial systems for forming and expressing emotions. There are reciprocal projections between the hypothalamus, anterior cingulate cortex and prefrontal orbital cortex, and between the hypothalamus and the amygdale. Therefore, destruction of the mediodorsal thalamic nucleus and the hypothalamus can cause abnormal expression of emotions. Recently, converging evidence suggests that the pulvinar nucleus in the posterior thalamus mediates emotional visual information processing through the colliculo-pulvino-amygdalar pathway and/or through the colliculo-pulvino-cortical pathways. These pathways seem to contribute to the unconscious and/or conscious fast processing of ecologically relevant stimuli. Therefore, destruction of the pulvinar can cause impaired reaction to visual threats, such as photographs of a cockroach and fearfull facial expressions, if the stimuli are exposed briefly.