This inhibition in the pallidum disinhibits the thalamic target of the limbic loop, which is the mediodorsal nucleus.

Modern tract tracing studies have shown that projections of the mediodorsal nucleus of the thalamus are not restricted to the granular frontal cortex in primates.

The OFC projects and is neuronanatomically connected (via the mediodorsal nucleus of the thalamus) to the nucleus accumbens - which is associated with the reinforcing effects of drug administration.

As a result, it was suggested to define the prefrontal cortex as the region of cortex that has stronger reciprocal connections with the mediodorsal nucleus than with any other thalamic nucleus.

To define the prefrontal cortex as the projection zone of the mediodorsal nucleus of the thalamus builds on the work of Rose and Woolsey who showed that this nucleus projects to anterior and ventral parts of the brain in nonprimates.

Additionally, output is sent to the following: the mediodorsal nucleus of the Thalamus, the lateral Habenula, the Septal nuclei, the anterior Mammillary nuclei, the Nucleus of diagonal band, the Preoptic area, the Ventral tegmental area, and in some species the dorsal and/or lateral Hypothalmus.