Fig. 12.

Schematic of the mPFC regulation of BLA output and its modulation by DA. In this figure, neurons of the mPFC and Te3 that project to the BLA are represented by triangles,and their level of activity is represented by firing rate histograms within the triangles. The dominant input is represented by abolder line connecting the cortical area with the BLA. BLA projection neuron (triangle) activity is represented by hypothetical voltage traces within the triangle. A,Enhanced mPFC activity (1) will decrease BLA output (hyperpolarization; 2) caused by activation of a BLA inhibitory interneuron (3). B,Enhanced sensory cortical activity (1) will lead to action potential firing (2) in BLA projection neurons. C, mPFC inputs (1) that occur concomitant with sensory cortical inputs (2) will dampen the spike firing that is induced by sensory cortical inputs under basal conditions (EPSP without action potential; 3). D, If the sensory stimulus has affective value, DA is released in the BLA. In the presence of DA (1), the BLA output will be enhanced (numerous action potentials; 4) by a combination of attenuated mPFC inputs (2) to interneurons, and augmented sensory cortical inputs (3).