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Medial dorsal nucleus

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Not to be confused with?Dorsomedial hypothalamic nucleus.

Medial dorsal nucleus

?

Thalamic nuclei:?
MNG =?Midline nuclear group
AN =?Anterior nuclear group
MD = Medial dorsal nucleus
VNG =?Ventral nuclear group
VA =?Ventral anterior nucleus
VL =?Ventral lateral nucleus
VPL =?Ventral posterolateral nucleus
VPM =?Ventral posteromedial nucleus
LNG =?Lateral nuclear group
PUL =?Pulvinar
MTh =?Metathalamus
LG =?Lateral geniculate nucleus
MG =?Medial geniculate nucleus

?

Thalamic nuclei

Details

Identifiers

Latin

nucleus mediodorsalis thalami

MeSH

D020645

NeuroNames

312

NeuroLex?ID

birnlex_1543

TA

A14.1.08.622

FMA

62156

Anatomical terms of neuroanatomy

[edit on Wikidata]

The?medial dorsal nucleus?(or?dorsomedial nucleus of thalamus) is a large?nucleus?in the?thalamus.

It is believed to play a role in?memory.[1]

Contents

·?1Structure

·?2Function

·?2.1Pain processing

·?2.2Saccadic efference copy

·?3Clinical significance

·?4Additional images

·?5References

·?6External links

Structure[edit]

It relays inputs from the amygdala and olfactory cortex and projects to the?prefrontal cortex?and the?limbic system?and in turn relays them to the prefrontal?association cortex. As a result, it plays a crucial role in attention, planning, organization, abstract thinking, multi-tasking, and active memory.[citation needed]

（樂趣與好處。有好處才會(huì)有attention，這個(gè)狀態(tài)應(yīng)該是serotonin對(duì)NAcc shell強(qiáng)烈作用使得NAcc shell工作狀態(tài)低下，從而降低了對(duì)VTA和副交感系統(tǒng)的抑制，所以人處于注意集中的狀態(tài)時(shí)交感系統(tǒng)一點(diǎn)都不活躍，同時(shí)ventral pallidum也得不到NAcc shell的抑制，那么此時(shí)NE system工作狀態(tài)提升，如果所注意（比如聽講）內(nèi)容帶不來好處，就會(huì)因?yàn)镹E積累而交感系統(tǒng)逐漸興起，如果所注意內(nèi)容帶來好處，就意味著有持續(xù)的serotonin產(chǎn)生來抵消積累的NE，作用在NAcc shell也能得到補(bǔ)充。所以，當(dāng)保持注意狀態(tài)一定時(shí)間是需要釋放一下DA system，釋放一下交感系統(tǒng)。導(dǎo)盲犬工作中就是注意集中的狀態(tài)，導(dǎo)盲犬也需要放松玩鬧。所以，能否帶來好處是關(guān)鍵。樂趣，是substantia nigra pars compacta的大爆發(fā)，其中nucleus accumbens一定不能被抑制。這里給出了一種處于attention狀態(tài)的原因，NAcc shell被serotonin“抑制”，且所注意的內(nèi)容能帶來好處（也即是serotonin），否則就坐不住了，這種注意狀態(tài)需要通過課間時(shí)間來釋放一下DA system。記得上學(xué)期間，那些聰明的、學(xué)習(xí)好的孩子課間都出去玩。我自己有一次初中模考，中間休息的時(shí)候在操場瘋跑，下一科的理科考試考得就非常好，當(dāng)時(shí)我自己都有點(diǎn)意料之外，因?yàn)榭纪晡覜]有覺得有多好，出成績后我也想不起來為什么考得這么好。）

The connections of the medial dorsal nucleus have even been used to delineate the prefrontal cortex of the?G?ttingen minipig?brain.[2]

By?stereology?the number of?brain cells?in the region has been estimated to around 6.43 million?neurons?in the adult human brain and 36.3 million?glial cells, and with the newborn having quite different numbers: around 11.2 million neurons and 10.6 million glial cells.[3]

Function[edit]

Pain processing[edit]

While both the ventral and medial dorsal nuclei process pain, the medial dorsal nucleus bypasses primary cortices, sending their axons directly to secondary and association cortices. The cells also send axons directly to many parts of the brain, including nuclei of the limbic system such as the lateral nucleus of the amygdala, the anterior cingulate, and the hippocampus. This part of the sensory system, known as the non-classical or?extralemniscal system?is less accurate, and less detailed in regards to sensory signal analysis. This processing is known colloquially as "fast and dirty" rather than the "slow and accurate" system of classical or lemniscal system. This pathway activates parts of the brain that evoke emotional responses.[citation needed]

Saccadic efference copy[edit]

This nucleus is also presumed to play a role in monitoring internal movements of the eye. Specifically, its function is to relay the information about how the eyes will be moved (efference copy, also known as corollary discharge) from the superior colliculus to the frontal eye fields (FEF) in order to aid the neurons in FEF to change their receptive fields to where the visual stimuli will appear after the saccade.[4]

Clinical significance[edit]

Damage to the medial dorsal nucleus has been associated with?Korsakoff's syndrome.[5]

（dorsomedial nucleus of thalamus這么重要的結(jié)構(gòu)，在這個(gè)詞條中居然沒有一個(gè)有用的信息，也沒有明確反映結(jié)構(gòu)和連接關(guān)系的信息，可見現(xiàn)在的研究水平是多么低，其實(shí)也難怪，只有primates具有dorsomedial nucleus of thalamus和granular prefrontal cortex，在我看來，能搞懂dorsomedial nucleus of thalamus的結(jié)構(gòu)和功能，就基本解決了人類獨(dú)有的復(fù)雜行為和智力。唉，最重要的結(jié)構(gòu)，最關(guān)鍵的結(jié)構(gòu)，往往是信息最少的。不過我從其他地方了解到一些關(guān)鍵信息，比如dorsomedial nucleus of thalamus與prefrontal cortex之間存在reciprocal connection, prefrontal cortex接受初級(jí)視覺皮層的投射，自身還投射到parietal cortex where is also the target of vision information(當(dāng)你看黑白電視的時(shí)候，parietal cortex接受的視覺信息就少了來自prefrontal cortex的顏色，所以感覺起來不是那么開心，不過你還是可以通過常識(shí)來興奮dorsomedial nucleus of thalamus，從而“腦補(bǔ)”那些缺失的顏色)；不需要外界信息就可以自發(fā)放電的ventral pallidum投射抑制軸突到dorsomedial nucleus of thalamus；amygdala投射到dorsomedial nucleus of thalamus；pontine ACh system投射到dorsomedial nucleus of thalamus；我的一個(gè)預(yù)測性假設(shè)（其實(shí)是我從另一個(gè)wiki詞條中看到的，但是后來就再也找不到了，就只能成為假設(shè)）是temporal cortex投射到dorsomedial nucleus of thalamus。其注意，這里amygdala（代表NE system）、pontine ACh system和ventral pallidum（代表DA system）輪番對(duì)dorsomedial nucleus of thalamus影響，這對(duì)應(yīng)著起碼三種不同興奮dorsomedial nucleus of thalamus的模式，進(jìn)而三種不同興奮prefrontal cortex的模式，也對(duì)應(yīng)了起碼的三種不同的行為狀態(tài)，這才是揭秘人類獨(dú)有的復(fù)雜行為和智力的關(guān)鍵，對(duì)應(yīng)著規(guī)則行為、目的行為和興趣行為。這也是我可以直接用觀察的行為來證明我的理論的一個(gè)途徑。而語言是temporal cortex投射dorsomedial nucleus of thalamus互射prefrontal cortex的結(jié)構(gòu)記憶，也是我可以直接用觀察的行為來證明我的理論的一個(gè)途徑。就先寫這些吧，我很想寫hippocampus--cingulate cortex circuit，這個(gè)更重要，但是內(nèi)容更多更復(fù)雜，我不知道最近還能否有如此多的、不受打擾的時(shí)間，去紀(jì)錄更復(fù)雜的wiki筆記。還有就是最近新發(fā)現(xiàn)的狀態(tài)原理，涉及habenular cortex、diagonal band of Broca、interpeduncular nucleus、periaqueductal gray、pedunculopontine nucleus等等，對(duì)應(yīng)著大腦最隱秘的思維狀態(tài)，也就是說基本沒有外在表現(xiàn)的、基本不留下記憶的、只留下思維結(jié)果的思維狀態(tài)，包含清醒狀態(tài)下和REM睡眠狀態(tài)下的神經(jīng)工作機(jī)制。）