PT  - JOURNAL ARTICLE
AU  - Aaron M. Jasnow
AU  - David E. Ehrlich
AU  - Dennis C. Choi
AU  - Joanna Dabrowska
AU  - Mallory E. Bowers
AU  - Kenneth M. McCullough
AU  - Donald G. Rainnie
AU  - Kerry J. Ressler
TI  - Thy1-Expressing Neurons in the Basolateral Amygdala May Mediate Fear Inhibition
AID  - 10.1523/JNEUROSCI.5539-12.2013
DP  - 2013 Jun 19
TA  - The Journal of Neuroscience
PG  - 10396--10404
VI  - 33
IP  - 25
4099  - http://www.jneurosci.org/content/33/25/10396.short
4100  - http://www.jneurosci.org/content/33/25/10396.full
SO  - J. Neurosci.2013 Jun 19; 33
AB  - Research has identified distinct neuronal circuits within the basolateral amygdala (BLA) that differentially mediate fear expression versus inhibition; however, molecular markers of these populations remain unknown. Here we examine whether optogenetic activation of a cellular subpopulation, which may correlate with the physiologically identified extinction neurons in the BLA, would differentially support fear conditioning versus fear inhibition/extinction. We first molecularly characterized Thy1-channelrhodopsin-2 (Thy1-ChR2-EYFP)-expressing neurons as a subpopulation of glutamatergic pyramidal neurons within the BLA. Optogenetic stimulation of these neurons inhibited a subpopulation of medial central amygdala neurons and shunted excitation from the lateral amygdala. Brief activation of these neurons during fear training disrupted later fear memory in male mice. Optogenetic activation during unreinforced stimulus exposure enhanced extinction retention, but had no effect on fear expression, locomotion, or open-field behavior. Together, these data suggest that the Thy1-expressing subpopulation of BLA pyramidal neurons provide an important molecular and pharmacological target for inhibiting fear and enhancing extinction and for furthering our understanding of the molecular mechanisms of fear processing.