Saturday, August 15, 2009

Ventral Tegmental Area

The ventral tegmental area is a group of neurons located close to the midline on the floor of the midbrain. The The ventral tegmental area (VTA) is involved in the drug and natural reward circuitry of the brain, cognition, and motivation. The VTA contains neurons that project to numerous areas of the brain, from the prefrontal cortex to the caudal brainstem and everywhere in between. The ventral tegmental area forwards information to another structure further forward in the brain: the nucleus accumbens. In order to send information to the nucleus accumbens, the VTA uses a neurotransmitter called dopamine.

It is very difficult to distinguish the ventral tegmental area in humans and other primate brains from the substantia nigra and other surrounding nuclei. The VTA is located in the midbrain between the mammilary bodies and the posterior hypothalamus. The pons is situated caudally to the VTA and the substantia nigra is lying laterally to the VTA. The ventral tegmental area has also been shown to process various types of emotion output from the amygdala, where it may also play a role in avoidance and fear-conditioning. In terms of human evolution, the ventral tegmental area is one of the most primitive part of the brain.