LeDoux Lab 2012 SfN Abstracts
 
Program#/Poster#: 834.11
Title: Temporal dynamics in coherent delta and theta oscillations within the amygdalo-prefronto-striatal network as correlates of interval timing in rats
Location: 387
Presentation Time: Wednesday, Oct 17, 2012, 3:30 PM - 3:45 PM
Authors: *J. KNIPPENBERG1,2, M. GRAUPNER3, L. DIAZ-MATAIX3, J. LEDOUX3,4, V. DOYERE1,2,3;
1UMR 8195, Ctr. De Neurosciences Paris-Sud, Orsay, France; 2CNRS, Orsay, France; 3Ctr. for Neural Sci., New York, NY; 4Emotional Brain Inst., Nathan S. Kline Inst. for Psychiatry Res., Orangeburg, NY
Abstract: Humans and animals have the capacity to estimate durations ranging from seconds to minutes, a cognitive ability named interval timing. Neural structures traditionally implicated in interval timing are the medial prefrontal cortex (mPFC) and dorsal striatum. Findings from our labs have shown that the amygdala is involved in responding to changes in the timing of shocks in Pavlovian fear conditioning. Despite this anatomical delimitation, relatively little is known about the neurophysiological processes within these structures that ultimately mediate interval timing. Here, we sought to indentify neurophysiological correlates within the mPFC, dorsal striatum and basal amygdala using a modified fear conditioning procedure in rats, in which two different auditory tones served as conditioned stimuli (CS, 1 or 11 kHz, each 60-s long) signalling two different arrival times (at 10 or 30 s during the CS) of a footshock unconditioned stimulus (US). Rats were food deprived and trained to press a lever to obtain occasional food rewards. During fear conditioning CS-US pairings as well as CSs alone (probe trials) were presented independent of ongoing lever pressing activity and the food reinforcement schedule. Conditioned suppression of lever pressing during the 60-s CS probe trials demonstrated a temporal pattern of US anticipation with a peak before the time of US delivery. After stable temporal behavior was acquired rats were implanted with electrodes aimed at mPFC, dorsal striatum and basal amygdala. Then, local field potential (LFP) recordings were obtained as rats were again subjected to the conditioning protocol. Probe trials were used for LFP analysis. The power spectral density of the entire 60-s CS epoch contained two dominant frequency bands: a delta (1-4 Hz) and theta (5-8 Hz) rhythm. Coherence between pairs of recorded structures showed timing-related changes within the theta band, and to a lesser extent also within the delta band. As the mPFC, dorsal striatum and basal amygdala are anatomically interconnected, these initial results might point to a role of theta and delta oscillations within an amygdalo-prefronto-striatal network in encoding the timing of biological significant events and/or the mediation of temporal behavior.
Support: ANR Memotime
ANR TDE
LIA Emotime
PUF Emotion & Timing