Ventral Tegmental Area - Inputs

Inputs

Almost all areas receiving projections from the VTA project back to it. Thus, the ventral tegmentum is reciprocally connected with a wide range of structures throughout the brain suggesting that it has a role in the control of function in the phylogenetically new and highly developed neocortex, as well as that of the phylogenetically older limbic areas.

There are excitatory glutamatergic afferents that arise from almost every structure that projects into the VTA, except the NAC and the lateral septum. These glutamatergic afferents play a key role in regulating VTA cell firing. When the glutamatergic neurons are activated, the firing rates of the dopamine neurons increase in the VTA and induce burst firing. Studies have shown that these glutamatergic actions in the VTA are critical to the effects of drugs of abuse.

Subpallidal afferents into the VTA are mainly GABAergic and, thus, inhibitory. There is a substantial pathway from the subpallidal area to the VTA. When this pathway is disinhibited, an increase in the dopamine release in the mesolimbic pathway amplifies locomotor activity.