 For example, studies have shown that the entorhinal cortex may gate areas of the medial PFC, thereby inhibiting them from projecting to other brain areas.Additional research has shown that the thalamus can also act as a source for gating signals.In the pathway between the PFC and the hippocampus, stimulation of mediodorsal thalamic neurons, as well as stimulation of ventral tegmental area neurons inhibited PFC neuron firing.