The basal forebrain is a collection of structures located ventrally to the striatum

Striatum

The striatum, also known as the neostriatum or striate nucleus, is a subcortical part of the forebrain. It is the major input station of the basal ganglia system. The striatum, in turn, gets input from the cerebral cortex...

. It is considered to be the major cholinergic output of the central nervous system

Central nervous system

The central nervous system is the part of the nervous system that integrates the information that it receives from, and coordinates the activity of, all parts of the bodies of bilaterian animals—that is, all multicellular animals except sponges and radially symmetric animals such as jellyfish...

 (CNS). It includes a group of structures that lie near the bottom of the front of the brain, including the nucleus basalis, diagonal band of Broca

Diagonal band of Broca

The diagonal band of Broca forms the medial margin of the anterior perforated substance.-Contents:It consists of fibers that are said to arise in the parolfactory area, the gyrus subcallosus and the anterior perforated substance, and course backward in the longitudinal striae to the dentate gyrus...

, and medial septal nuclei

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...

. These structures are important in the production of acetylcholine

Acetylcholine

The chemical compound acetylcholine is a neurotransmitter in both the peripheral nervous system and central nervous system in many organisms including humans...

, which is then distributed widely throughout the brain.

Function

Acetylcholine affects the ability of brain cells to transmit information to one another, and also encourages plasticity, or learning. Thus, damage to the basal forebrain can reduce the amount of acetylcholine in the brain and impair learning. The name forebrain can be confusing because "fore" usually stands for "front", and in this case "forebrain" stands for the top of the brain. This may be one reason why basal forebrain damage can result in memory impairments such as amnesia and confabulation. One common cause of basal forebrain damage is aneurysm of the anterior communicating artery.
Research, conducted by investigators from Children's Hospital Boston

Children's Hospital Boston

Children's Hospital Boston is a 396-licensed bed children's hospital in the Longwood Medical and Academic Area of Boston, Massachusetts.At 300 Longwood Avenue, Children's is adjacent both to its teaching affiliate, Harvard Medical School, and to Dana-Farber Cancer Institute...

 and the University of Helsinki

University of Helsinki

The University of Helsinki is a university located in Helsinki, Finland since 1829, but was founded in the city of Turku in 1640 as The Royal Academy of Turku, at that time part of the Swedish Empire. It is the oldest and largest university in Finland with the widest range of disciplines available...

, ties together previous observations about sleep and finds that nitric oxide

Nitric oxide

Nitric oxide, also known as nitrogen monoxide, is a diatomic molecule with chemical formula NO. It is a free radical and is an important intermediate in the chemical industry...

 production in the basal forebrain is both necessary and sufficient to produce sleep

Sleep

Sleep is a naturally recurring state characterized by reduced or absent consciousness, relatively suspended sensory activity, and inactivity of nearly all voluntary muscles. It is distinguished from quiet wakefulness by a decreased ability to react to stimuli, and is more easily reversible than...

.

This structure is defined, in part, as the place where adenosine acts on A1 receptors of cholinergic

Cholinergic

The word choline generally refers to the various quaternary ammonium salts containing the N,N,N-trimethylethanolammonium cation. Found in most animal tissues, choline is a primary component of the neurotransmitter acetylcholine and functions with inositol as a basic constituent of lecithin...

 neurons. This results in hyperpolarization

Hyperpolarization

Hyperpolarization has several meanings:* Hyperpolarization occurs when the strength of the electric field across the width of a cell membrane increases...

 of cholinergic neurons, which inhibits the release of acetylcholine

Acetylcholine

The chemical compound acetylcholine is a neurotransmitter in both the peripheral nervous system and central nervous system in many organisms including humans...

. Acetylcholine is known to promote wakefulness in the basal forebrain. Inhibition of acetylcholine release in the basal forebrain by adenosine causes slow wave sleep.

The basal forebrain and adjacent areas are a focus for sleep research. Stimulating the basal forebrain gives rise to Ach release, which induces wakefulness and REM sleep.

External links

• NIF Search - Basal Forebrain via the Neuroscience Information Framework
  Neuroscience Information Framework
  The Neuroscience Information Framework is a repository of global neuroscience web resources, including experimental, clinical, and translational neuroscience databases, knowledge bases, atlases, and genetic/genomic resources.-Description:...