Effects of stimulation of the frontal cortex on identified output VMT cells in the rat

The neurons located in the mesencephalic ventro-medial tegmentum (VMT) and projecting to the nucleus accumbens, the septum and the frontal cortex were identified by the antidromic activation method. The activity of single VMT cells was extracellularly recorded in Ketamine anaesthetized rats. The effect of the stimulation of the medial frontal cortex on the activity of these identified VMT cells has been studied. The main response observed was an excitation which was followed in some cases by a depression of the spontaneous discharge of the cells.