Basal ganglia circuits are organized as parallel loops that have been proposed to compete in a winner-take-all fashion to determine the appropriate behavioral outcome. However, limited experimental support for strong lateral inhibition mechanisms within striatal regions questions this model. Here, stimulation of the prefrontal cortex (PFC) using naturally occurring bursty patterns inhibited firing in most nucleus accumbens (NA) projection neurons. When an excitatory response was observed for one stimulation site, neighboring PFC sites evoked inhibition in the same neuron. Furthermore, PFC stimulation activated interneurons, and PFC-evoked inhibition was blocked by GABA(A) antagonists in corticoaccumbens slice preparations. Thus bursting PFC activity recruits local inhibition in the NA, shaping responses of projection neurons with a topographical arrangement that allows inhibition among parallel corticoaccumbens channels. The data indicate a high order of information processing within striatal circuits that should be considered in models of basal ganglia function and disease.
ruber, Aaron JPowell, Elizabeth MO'Donnell, PatricioMH-60131/MH/NIMH NIH HHS/United StatesIn VitroResearch Support, N.I.H., ExtramuralResearch Support, Non-U.S. Gov'tUnited StatesJournal of neurophysiologyJ Neurophysiol. 2009 Apr;101(4):1876-82. doi: 10.1152/jn.91002.2008. Epub 2009 Jan 28.