LeDoux Lab 2004 SfN Abstracts

SINGLE-UNIT ACTIVITY IN THE MEDIAL PREFRONTAL CORTEX DURING PARTIALLY REINFORCED FEAR CONDITIONING
J.C.Erlich*; J.S.Choi; J.E.LeDoux
Ctr. for Neural Sci., New York Univ., New York, NY, USA
Behavioral and physiological evidence implicate the medial pre-frontal cortex (mPFC) as an important structure for regulating emotion. Field potentials recorded in mPFC during fear conditioning are inversely correlated with fear behavior and single-unit responses from mPFC neurons show memory for fear extinction. To further understand information encoding by mPFC neurons, rats were trained with a conditioned stimulus (CS, 12KHz pulsiform auditory, 80 dB, 20 sec) paired with an unconditioned stimulus (US, low intensity periorbital shock) using a partial reinforcement schedule. The subjects had free access to Kool-Aid in a drinking tube and the degree to which the CS suppressed licking was a measure of fear. Single units were recorded from the mPFC via chronically implanted electrodes. CS-elicited unit responses were compared when licking was suppressed by the CS vs. times when licking was not suppressed. For cells that were inhibited by the CS this inhibition was larger during licking than suppression. For cells that were excited by the CS this excitation was larger during licking than suppression. The relative timing of the responses of these two classes of cells, excited vs. inhibited, gives an interesting picture of cortical microcircuitry, in that the difference in response in the two behavioral conditions is mirrored in the two cell types. Support Contributed By: MH3877; J.C.E is an HHMI Pre-Doctoral Fellow
Program No. 208.7 Poster presentation:Sunday, Oct. 24, 10:00 AM - 11:00 AM Location: NN22