REPRESENTATION OF THE BODY IN THE LATERAL STRIATUM OF THE FREELY MOVING RAT - SINGLE NEURONS RELATED TO LICKING

This study examined the relationship of single-neuron activity (n = 73 9), recorded from the lateral striatum of freely moving rats, to oral movements involved in licking single drops of liquid. Certain neurons (n = 74) fired specifically in relation to licking. Their firing rates increased during licking, but remained near zero in the absence of li cking, throughout a full sensorimotor examination of the remainder of the orofacial area and all other body parts. Another category of neuro ns (n = 17) fired during licking but also fired in the absence of lick ing, during one or more other orofacial sensorimotor function(s). Lick -related neurons were located in the lateral striatum, throughout the entire anterior-posterior range studied (from + 1.5 to - 1.5 mm anteri or-posterior, A-P, bregma = 0). Summed over the full A-P range, they w ere located significantly ventral to representations of the trunk and limbs. These findings extend the characterization of the somatotopic o rganization exhibited by lateral striatal neurons in the rat, to inclu de representation of oral functions, consistent with converging eviden ce regarding the functional organization of the striatum.