Yong Sang Jo, Ph.D.
May 20(Thu) - May 20(Thu), 2021
12PM
ZOOM (ID: 728-142-6028)
Neuro@noon Seminar
Date: 12PM, Thursday, May 20th
ZOOM 회의 참가 ID: 728-142-6028
Speaker: Yong Sang Jo, Ph.D.
(School of Psychology, Korea University)
Title: Dopaminergic modulation of fear acquisition and extinction
Abstract:
Midbrain dopamine neurons are known to encode differences between actual and
expected outcomes. Such prediction errors are critical for forming an associative relationship
between a cue and its consequence. The roles of dopaminergic signals on reinforcement learning
have long been investigated, but less attention has been paid to dopaminergic contributions
to aversive association learning. Here we demonstrate evidence that dopamine neurons encode
associative information of threat-predictive cues in Pavlovian fear conditioning and manipulations
of dopamine activity can modulate animals' performance in discriminative fear learning.
In addition, dopamine neurons also signaled prediction errors in response to the absence
of expected threats during the extinction training of fear memory. When the prediction error
signaling was optogenetically increased during extinction, animals extinguished the fear memory
at a significantly faster rate. We further examined how dopamine releases during threat learning
and extinction influenced neural activity in the amygdala, the core brain structure underlying fear
and defensive responses. Overall, our results indicate that midbrain dopamine systems are one of
the key factors in aversive fear learning and extinction.