The effects of calcitonin on central neurons in the rat.

The effects of salmon calcitonin on central neurons were studied in anesthetized rats. Calcitonin applied iontophoretically consistently inhibited spontaneous activity in half of the neurons tested in the anterior hypothalamic nucleus and subthalamus but had virtually no effect on cortical and thalamic neurons. Calcitonin also inhibited glutamate-evoked activity in the neurons tested. Calcitonin administered into the brain ventricular system led to a marked decrease in spontaneous discharge of hypothalamic cells in the majority of cells tested. The onset of this response began within 20 and 30 min of calcitonin application.