Medial forebrain bundle

The Medial forebrain bundle (MFB) is a bundle of the axon that carries information between the ventral tegmentum and the nucleus accumbens. It is commonly accepted that the MFB is involved in the integration of reward and pleasure.

Electrical stimulation of the medial forebrain bundle is believed to cause sensations of pleasure. This hypothesis is based upon intracranial self-stimulation (ICSS) studies. Animals will work for MFB ICSS, and humans report that MFB ICSS is intensely pleasurable. This is most likely because the medial forebrain bundle carries information ventral tegmental area (VTA) to the nucleus accumbens (nAcc or Acb). The nAcc is a recognized reward center, and activation of the pathway from the VTA to the nAcc is believed to be rewarding.