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| {{short description|Brain structures in the forebrain}} | | {{Short description|Region of the brain associated with memory and learning}} |
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| | Name = Basal forebrain
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| | Latin = pars basalis telencephali
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| | Image = Basal_Forebrain_Monakhos_2007.png
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| | Caption = The basal forebrain
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| Part of the human brain, the '''basal forebrain''' structures are located in the [[forebrain]] to the front of and below the [[striatum]]. They include the ventral basal ganglia (including [[nucleus accumbens]] and [[ventral pallidum]]), [[nucleus basalis]], [[diagonal band of Broca]], [[substantia innominata]], and the [[medial septal nucleus]]. These structures are important in the production of [[acetylcholine]], which is then distributed widely throughout the brain. The basal forebrain is considered to be the major [[cholinergic]] output of the [[central nervous system]] (CNS) centred on the output of the nucleus basalis.<ref name="Goard">{{cite journal |last1=Goard |first1=M |last2=Dan |first2=Y |title=Basal forebrain activation enhances cortical coding of natural scenes. |journal=Nature Neuroscience |date=November 2009 |volume=12 |issue=11 |pages=1444–9 |doi=10.1038/nn.2402 |pmid=19801988|pmc=3576925 }}</ref> The presence of non-cholinergic neurons projecting to the cortex have been found to act with the cholinergic neurons to dynamically modulate activity in the cortex.<ref name="Lin">{{cite journal |last1=Lin |first1=SC |last2=Brown |first2=RE |last3=Hussain Shuler |first3=MG |last4=Petersen |first4=CC |last5=Kepecs |first5=A |title=Optogenetic Dissection of the Basal Forebrain Neuromodulatory Control of Cortical Activation, Plasticity, and Cognition. |journal=The Journal of Neuroscience |date=14 October 2015 |volume=35 |issue=41 |pages=13896–903 |doi=10.1523/JNEUROSCI.2590-15.2015 |pmid=26468190|pmc=4604228 }}</ref>
| | The '''basal forebrain''' is a region located at the base of the [[forebrain]] and is involved in various functions including [[memory]], [[learning]], and [[attention]]. It is a critical area for the production of [[acetylcholine]], a neurotransmitter that plays a significant role in cognitive processes. |
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| ==Function== | | ==Anatomy== |
| Acetylcholine is known to promote wakefulness in the basal forebrain. Stimulating the basal forebrain gives rise to acetylcholine release, which induces [[wakefulness]] and [[REM sleep]], whereas inhibition of acetylcholine release in the basal forebrain by adenosine causes [[slow wave sleep]]. The nucleus basalis is the main [[neuromodulation|neuromodulator]] of the basal forebrain and gives widespread [[cholinergic]] projections to the neocortex.<ref name="Gratwicke">{{cite journal |last1=Gratwicke |first1=J |last2=Kahan |first2=J |last3=Zrinzo |first3=L |last4=Hariz |first4=M |last5=Limousin |first5=P |last6=Foltynie |first6=T |last7=Jahanshahi |first7=M |title=The nucleus basalis of Meynert: a new target for deep brain stimulation in dementia? |journal=Neuroscience and Biobehavioral Reviews |date=December 2013 |volume=37 |issue=10 Pt 2 |pages=2676–88 |doi=10.1016/j.neubiorev.2013.09.003 |pmid=24035740|s2cid=31426719 }}</ref><ref name="Goard"/> The nucleus basalis is an essential part of the neuromodulatory system that controls behaviour by regulating [[arousal]] and [[attention]].<ref name="Goard"/> The nucleus basalis is also seen to be a critical node in the memory circuit.<ref name="Lv">{{cite journal |last1=Lv |first1=Q |last2=Du |first2=A |last3=Wei |first3=W |last4=Li |first4=Y |last5=Liu |first5=G |last6=Wang |first6=XP |title=Deep Brain Stimulation: A Potential Treatment for Dementia in Alzheimer's Disease (AD) and Parkinson's Disease Dementia (PDD). |journal=Frontiers in Neuroscience |date=2018 |volume=12 |pages=360 |doi=10.3389/fnins.2018.00360 |pmid=29896085|pmc=5986883 |doi-access=free }}</ref>
| | The basal forebrain is situated near the [[hypothalamus]] and [[thalamus]], and it encompasses several structures, including the [[nucleus basalis]], the [[medial septal nucleus]], the [[diagonal band of Broca]], and parts of the [[substantia innominata]]. These structures are interconnected and work together to modulate cortical activity. |
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| The importance of non-cholinergic neurons in the basal forebrain structures has been shown in working together with the cholinergic neurons in a dynamically modulatory way. This is seen to play a significant role in cognitive functions.<ref name="Lin"/> | | ===Nucleus Basalis=== |
| | The [[nucleus basalis]] is a group of neurons located in the basal forebrain that is rich in [[cholinergic]] neurons. It is primarily involved in the modulation of [[cortical]] activity and is crucial for [[attention]] and [[arousal]]. |
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| [[Adenosine]] acts on [[Adenosine A1 receptor|A1 receptors]] of [[cholinergic]] neurons in the basal forebrain. This results in [[hyperpolarization (biology)|hyperpolarization]] of cholinergic neurons, which inhibits the release of [[acetylcholine]].{{cn|date=September 2021}} | | ===Medial Septal Nucleus=== |
| | The [[medial septal nucleus]] is another component of the basal forebrain, which plays a role in the regulation of [[hippocampal]] activity. It is involved in the generation of [[theta rhythm]], which is important for [[memory]] encoding and retrieval. |
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| [[Nitric oxide]] production in the basal forebrain is both necessary and sufficient to produce [[sleep]].<ref>[https://www.sciencedaily.com/releases/2006/09/060908094456.htm Need To Pull An All-nighter? Reducing Nitric Oxide Gas In The Brain May Help Us Stay Awake<!-- Bot generated title -->]</ref> | | ===Diagonal Band of Broca=== |
| | The [[diagonal band of Broca]] is a structure that connects the medial septal nucleus to the [[olfactory bulb]] and the [[hippocampus]]. It is involved in the processing of [[olfactory]] information and also contributes to [[learning]] and [[memory]]. |
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| ==Clinical significance== | | ===Substantia Innominata=== |
| Acetylcholine affects the ability of brain cells to transmit information to one another, and also encourages [[neuronal 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 an [[aneurysm]] of the [[anterior communicating artery]].<ref>{{Cite web |url=http://www.memorylossonline.com/glossary/basalforebrain.html |title=Memory Loss & the Brain<!-- Bot generated title --> |access-date=2006-04-11 |archive-url=https://web.archive.org/web/20060425165724/http://www.memorylossonline.com/glossary/basalforebrain.html |archive-date=2006-04-25 |url-status=dead }}</ref>
| | The [[substantia innominata]] is a region that contains a mixture of different types of neurons, including cholinergic neurons. It is involved in the regulation of [[cortical]] activity and plays a role in [[cognitive]] functions. |
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| It is thought that damage to the nucleus basalis and its cortical projections are implicated in forms of [[dementia]], notably [[Alzheimer's dementia]] and [[Parkinson's disease dementia]]. There have been studies on the use of [[deep brain stimulation]] to the nucleus basalis, in the treatment of dementia, and while giving some positive results trials are still being undertaken.<ref name="Lv"/><ref name="Gratwicke"/>{{Current event inline|date=February 2020|hide=y}}
| | ==Function== |
| | The basal forebrain is primarily known for its role in the production and release of [[acetylcholine]], which is essential for [[cognitive]] functions such as [[attention]], [[learning]], and [[memory]]. The cholinergic neurons in the basal forebrain project to various regions of the [[cortex]] and the [[hippocampus]], influencing [[cortical]] plasticity and [[synaptic]] transmission. |
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| ==References== | | ==Clinical Significance== |
| {{Reflist}}
| | Damage or degeneration of the basal forebrain is associated with several neurological conditions, including [[Alzheimer's disease]] and other forms of [[dementia]]. The loss of cholinergic neurons in this region is thought to contribute to the cognitive deficits observed in these disorders. |
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| {{Cerebral limbic system}}
| | ==Related pages== |
| {{Authority control}}
| | * [[Forebrain]] |
| | * [[Acetylcholine]] |
| | * [[Hippocampus]] |
| | * [[Alzheimer's disease]] |
| | * [[Cortex]] |
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| [[Category:Rostral basal ganglia and associated structures]] | | [[Category:Neuroanatomy]] |
| | [[Category:Forebrain]] |
Region of the brain associated with memory and learning
The basal forebrain is a region located at the base of the forebrain and is involved in various functions including memory, learning, and attention. It is a critical area for the production of acetylcholine, a neurotransmitter that plays a significant role in cognitive processes.
Anatomy[edit]
The basal forebrain is situated near the hypothalamus and thalamus, and it encompasses several structures, including the nucleus basalis, the medial septal nucleus, the diagonal band of Broca, and parts of the substantia innominata. These structures are interconnected and work together to modulate cortical activity.
Nucleus Basalis[edit]
The nucleus basalis is a group of neurons located in the basal forebrain that is rich in cholinergic neurons. It is primarily involved in the modulation of cortical activity and is crucial for attention and arousal.
Medial Septal Nucleus[edit]
The medial septal nucleus is another component of the basal forebrain, which plays a role in the regulation of hippocampal activity. It is involved in the generation of theta rhythm, which is important for memory encoding and retrieval.
Diagonal Band of Broca[edit]
The diagonal band of Broca is a structure that connects the medial septal nucleus to the olfactory bulb and the hippocampus. It is involved in the processing of olfactory information and also contributes to learning and memory.
Substantia Innominata[edit]
The substantia innominata is a region that contains a mixture of different types of neurons, including cholinergic neurons. It is involved in the regulation of cortical activity and plays a role in cognitive functions.
Function[edit]
The basal forebrain is primarily known for its role in the production and release of acetylcholine, which is essential for cognitive functions such as attention, learning, and memory. The cholinergic neurons in the basal forebrain project to various regions of the cortex and the hippocampus, influencing cortical plasticity and synaptic transmission.
Clinical Significance[edit]
Damage or degeneration of the basal forebrain is associated with several neurological conditions, including Alzheimer's disease and other forms of dementia. The loss of cholinergic neurons in this region is thought to contribute to the cognitive deficits observed in these disorders.
Related pages[edit]
