N-methyl-D-aspartate (NMDA) (0.5 and 1 microgram/0.5 microliter) bilaterally injected into the anterodorsal striatum of rats reduced locomotion, sniffing, rearing and feeding upon presentation of palatable food. Consequently, the number of all behavioural bouts exhibited was reduced and the duration of akinetic phases was prolonged. These results are discussed in connection with previous findings showing that the NMDA receptor blocker DL-2-amino-5-phosphonovaleric acid (AP-5) injected at the same site - produced opposite effects: AP-5 enhanced locomotion, rearing, sniffing as well as the total number of behavioural bouts exhibited.