Glutamate release was monitored in the lateral hypothalamus and the nucleus accumbens during a meal using 30 s resolution microdialysis and capillary zone electrophoresis with laser-induced fluorescence. A significant increase in hypothalamic glutamate and a decrease in accumbens glutamate were observed. These results, added to previous pharmacological studies, suggest that glutamatergic synapses in the lateral hypothalamus and the nucleus accumbens might be involved in the control of feeding behavior.