The primary concentration of cholinergic neurons/cell bodies that project to the neocortex are in the basal nucleus of Meynert which is located in the substantia innominata of the anterior perforated substance.
The nucleus basalis of Meynert in dementia. Cell counts in numerous human post-mortem studies show that up to 96% of NBM neurons are lost in both AD and PDD patients compared to age-matched controls (Candy et al., 1983, Etienne et al., 1986, Gaspar and Gray, 1984, Whitehouse et al., 1983 and Whitehouse et al., 1981). Dementia is a progressive disease and there is likely a limited window of opportunity to stimulate the remaining NBM fibres before the nucleus becomes too degenerate for stimulation to enhance its output, therefore patients may need to be implanted earlier in the disease course. The primary concentration of cholinergic neurons/cell bodies that project to the neocortex are in the basal nucleus of Meynert which is located in the substantia innominata of the anterior perforated substance.  The nucleus basalis of Meynert (NBM) is a small bundle of neurons in the basal forebrain that contains a high concentration of cholinergic neurons /9see image below). It is among the structures that shrink early on in AD (see Grothe et al., 2013). Stimulating the NBM might also be useful in other diseases, such as dementia with Lewy bodies, in which this area degenerates earlier and more extensively than it does in AD, he said. Electrodes were placed in the nucleus basalis of Meynert (arrows). The nucleus basalis magnocellularis (aka Nucleus Basalis of Meynert (' NBM)) is a nucleus in the basal ganglia. This is a group of cholinergic neurons in the substantia innominata of the basal forebrain which has wide projections to the neocortex and is rich in acetylcholine and choline acetyltransferase. In Parkinson and Alzheimer diseases the nucleus undergoes degeneration. A decrease in acetylcholine production is seen in Alzheimer's disease, Lewy body dementia and some Parkinson disease patients showing abnormal brain function, leading to a general decrease of mental capacity and learning. The nucleus accumbens (NAc or NAcc), also known as the accumbens nucleus or as the nucleus accumbens septi (Latin for nucleus adjacent to the septum) is a region in the basal forebrain rostral to the preoptic area of the hypothalamus.  Representation of the major anatomical structures and fibre tracts related to the nucleus basalis of Meynert (Ch4, in red) in the human basal forebrain region. Overlying structures have been lifted upward to expose the NBM, as indicated by dashed grey lines. Dementia is a progressive disease and there is likely a limited window of opportunity to stimulate the remaining NBM fibres before the nucleus becomes too degenerate for stimulation to enhance its output, therefore patients may need to be implanted earlier in the disease course. In cholinergic perikarya and dendrites of the Nucleus basalis magnocellularis (NBM), aging is associated with a decrease of the density of m2R at the plasma membrane and in the cytoplasm, suggesting a decrease of the total number of m2R in the somato-dendritic field. This immunotoxin induced a loss of choline acetyltransferase-positive neurons in the medial septum (-82%) and in the Nucleus basalis (-55%). BACKGROUND: It is well established that Nucleus basalis magnocellularis (NbM) lesions impair performance on tests of sustained attention. The primary concentration of cholinergic neurons/cell bodies that project to the neocortex are in the basal nucleus of Meynert which is located in the substantia innominata of the anterior perforated substance. In Parkinson and Alzheimer diseases the nucleus undergoes degeneration. A decrease in acetylcholine production is seen in Alzheimer's disease, Lewy body dementia and some Parkinson disease patients showing abnormal brain function, leading to a general decrease of mental capacity and learning. Medical Definition of NUCLEUS BASALIS. : the gray matter of the substantia innominata of the forebrain that consists mostly of cholinergic neurons. 2 ENTRIES FOUND: 1  nucleus basalis (noun)
http://www.sciencedirect.com/science/article/pii/S0149763413002066 https://en.wikipedia.org/wiki/Nucleus_basalis_of_Meynert http://www.alzforum.org/news/research-news/x-marks-spot-nucleus-basalis-dbs-alzheimers http://psychology.wikia.com/wiki/Nucleus_basalis_magnocellularis https://en.wikipedia.org/wiki/Nucleus_accumbens http://www.sciencedirect.com/science/article/pii/S0149763413002066 http://brainmaps.org/index.php?pm=Nucleus%20basalis http://psychology.wikia.com/wiki/Nucleus_basalis_magnocellularis http://www.merriam-webster.com/medical/nucleus%20basalis
what does the nucleus basalis do