background: alzheimer’s disease was known as a progressive neurodegenerative disorder in the elderly and is characterized by dementia and severe neuronal loss in the some regions of brain such as nucleus basalis magnocellularis. it plays an important role in the brain functions such as learning and memory. loss of cholinergic neurons of nucleus basalis magnocellularis by ibotenic acid can commo...

Recent studies have shown that estrogen replacement can enhance the functional status of basal forebrain cholinergic neurons. Studies have also shown that estrogen has neuroprotective effects both in vitro and in vivo on a variety of cells and against a variety of insults. The present study examined the ability of estrogen replacement to protect basal forebrain cholinergic neurons from the effe...

Rat frontal cortex neurons exhibit alterations in firing in response to a 2 sec tone cue followed by rewarding medial forebrain bundle (MFB) stimulation. Nucleus basalis neurons supply up to 75% of the cortical cholinergic innervation. The nucleus basalis and ACh have been implicated as playing a role in cognitive function. Three experiments were designed to test the hypothesis that the nucleus...

Auditory cortical receptive field plasticity produced during behavioral learning may be considered to constitute "physiological memory" because it has major characteristics of behavioral memory: associativity, specificity, rapid acquisition, and long-term retention. To investigate basal forebrain mechanisms in receptive field plasticity, we paired a tone with stimulation of the nucleus basalis,...

We have developed a neurocomputational model of some attentional e!ects of nicotine. Our simulations reproduce results showing smoking abstinence to impair performance on a rapid visual information processing task involving detecting sequences of even or odd digits. Our model treats presence of nicotine as enhancement of modulatory acetylcholine signals, which focus attention on task-relevant s...

The basal forebrain cholinergic system strongly influences both cortical plasticity and learning. Directly relating these two roles has proven difficult. New results indicate that nucleus basalis lesions prevent motor cortex map plasticity and impair skill learning. These results strengthen the hypothesis that nucleus basalis gates neural plasticity necessary for instrumental learning.

BACKGROUND Dementia represents one of the most challenging health problems. Despite intense research, available therapies have thus far only achieved modest results. Deep brain stimulation (DBS) is an effective treatment option for some movement disorders and is under study for psychiatric applications. Recently, diencephalic DBS revealed selective effects on memory functions, another facet of ...

In 22 patients with Alzheimer's disease loss of neurons from the nucleus basalis of Meynert and locus caeruleus averaged 58% and 71% respectively with nucleolar volume being reduced by 30% in both. These changes were greater in those patients under 80 years of age and in such patients damage to the locus was more severe than that to the nucleus basalis. In older patients (over 80 years) changes...