The striatal GABAergic microcircuit studied in this paper.
Primary input to the striatum comes from glutamatergic (GLU: ) fibres originating in the neocortex, thalamus, hippocampal formation and amygdala, and dopaminergic (DA: ▪) fibres originating in the hindbrain dopaminergic neuron bands. The medium spiny neurons (MSNs) are interconnected via local collaterals of their axons projecting to other nuclei of the basal ganglia. The fast-spiking interneurons (FSIs) can form dendro-dendritic gap junctions between them; they may also be connected by standard axo-dendritic synapses. All these intra-striatal axo-dendritic connections () are GABAergic and hence inhibitory.