The basal forebrain is a term for a group of structures that lie near the bottom of the front of the brain, including the nucleus basalis, diagonal band, medial septum and substantia innominata. These structures are important in the production of a brain chemical called acetylcholine, which is then distributed widely throughout the brain. 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. 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.

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Article : "CONFABULATION"