Does the Serotonin2C receptor segregate circuits of the basal ganglia responding to cingulate cortex stimulation?

Abstract

The relationships between cortical fields and the basal ganglia play a critical role in the control of motor behaviors, while the dysfunctional neuronal interplay within the cortico-basal ganglia circuits is involved in a variety of behavioral disorders. Using electrical stimulations of cortical regions and extracellular neuronal recordings in the substantia nigra pars reticulata (SNpr), it is possible to sequentially highlight three pathways linking input and output structures in rodents: the hyperdirect [subthalamic nucleus (STN)-SNpr, early excitatory, E1], the direct (striatonigral, inhibitory I), and the indirect [striatum-globus pallidus (GP)-STN- SNpr, late excitatory, E2) pathways.1 Our findings further recent evidence highlighting the pertinence of this model.2 Heckman et al2 showed that phosphodiesterase-4 inhibitors disrupt, in quantitative terms (magnitude, latency, and/or duration), the inhibitory and late excitatory phases of the SNpr neuronal triphasic responses to the infralimbic cortex stimulation. We report here that the 5-HT2C receptor (5-HT2CR) agonist WAY-163909 can impact on the existence of subcortical responses to the cortical stimulation.