A study on the brain structures related to conditioned emotional response by means of [14C]2-deoxy-D-glucose method

Brain structures activated during conditioned emotional response were studied by means of the [14C]2-deoxyglucose method. The experimental (CSE) animals were conditioned with paired 25 25-sec-long flicker sequences (CS) and 1-sec-long 150 V AC electric shocks (US), while the control (CSC) animals were given only 25 CS sequences. Average densities of a unit square (200 microns x 200 microns) of 47 nuclei or cortical areas in the left hemisphere were obtained from an autoradiogram and the optical density ratio (ODR), which is the relative optical density of each structure to that of the corpus callosum, was calculated. Comparison of ODRs of each structure from both groups revealed a significant increased uptake of [14C]2-deoxyglucose (P less than 0.05, Mann-Whitney U-test) in the caudal portion of area 10, area 2, area 18 and the hippocampal formation.