Non‐technical summary  Ca2+‐regulated axon terminal exocytosis is essential for neuronal communication in the CNS. Besides, the somata may also undergo Ca2+‐dependent exocytosis in some neurons in the brain. In the present work we recorded activity/Ca2+‐dependent secretion in somata of the mesencephalic trigeminal nucleus (MeV). Following nerve activity, somatic secretion signals are recorded as changes in membrane surface area, as measured by the membrane capacitance. The depolarization‐induced somatic exocytosis correlates with transient reduction in the GABA‐mediated postsynaptic currents. These results implicated that the somatic secretion may play a role in bidirectional communication between pre‐ and post‐connected neurons in the sensory MeV brain slice neurons.