Medial forebrain bundle
Encyclopedia
The Medial forebrain bundle (MFB), is a complex bundle of axons coming from the basal olfactory regions, the periamygdaloid region, and the septal nuclei
.
, with some carrying on into the tegmentum
. It contains both ascending and descending fibers. It also represents a part of the mesolimbic pathway
, carrying information between the ventral tegmentum
and the nucleus accumbens
.
, 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 from the 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, which is why it is sometimes referred to as the hedonic highway.
Septal nuclei
The septal area are structures that lie below the rostrum of corpus callosum in front of lamina terminalis , composed of medium-size neurons grouped into medial, lateral, and posterior groups...
.
Anatomy
It passes to the lateral hypothalamusHypothalamus
The Hypothalamus is a portion of the brain that contains a number of small nuclei with a variety of functions...
, with some carrying on into the tegmentum
Tegmentum
The tegmentum is a general area within the brainstem. It is located between the ventricular system and distinctive basal or ventral structures at each level...
. It contains both ascending and descending fibers. It also represents a part of the mesolimbic pathway
Mesolimbic pathway
The mesolimbic pathway is one of the dopaminergic pathways in the brain. The pathway begins in the ventral tegmental area of the midbrain and connects to the limbic system via the nucleus accumbens, the amygdala, and the hippocampus as well as to the medial prefrontal cortex...
, carrying information between the ventral tegmentum
Ventral tegmentum
The ventral tegmentum , better known as the ventral tegmental area , is a group of neurons located close to the midline on the floor of the midbrain...
and the nucleus accumbens
Nucleus accumbens
The nucleus accumbens , also known as the accumbens nucleus or as the nucleus accumbens septi , is a collection of neurons and forms the main part of the ventral striatum...
.
Function
It is commonly accepted that the MFB is a part of the reward systemReward system
In neuroscience, the reward system is a collection of brain structures which attempts to regulate and control behavior by inducing pleasurable effects...
, involved in the integration of reward and pleasure.
Electrical stimulation of the medial forebrain bundle is believed to cause sensations of pleasure
Pleasure center
Pleasure center is the general term used for the brain regions involved in pleasure. Discoveries made in the 1950s initially suggested that rodents could not stop electrically stimulating parts of their brain, mainly the nucleus accumbens, which was theorized to produce great 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 from the ventral tegmental area (VTA) to the nucleus accumbens
Nucleus accumbens
The nucleus accumbens , also known as the accumbens nucleus or as the nucleus accumbens septi , is a collection of neurons and forms the main part of the ventral striatum...
(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, which is why it is sometimes referred to as the hedonic highway.