wiki笔记--Retrosplenial cortex--2021/9/27
Retrosplenial cortex
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Retrosplenial cortex
Medial surface of the brain with Brodmann's areas numbered.
Details
Identifiers
Latin
Regio retrosplenialis
NeuroNames
2436, 1802
Anatomical terms of neuroanatomy
[edit on Wikidata]
The retrosplenial cortex (RSC) is a cortical area in the brain comprising Brodmann areas 29 and 30.[1] It is secondary association cortex, making connections with numerous other brain regions. The region's name refers to its anatomical location immediately behind the splenium of the corpus callosum in primates, although in rodents it is located more towards the brain surface and is relatively larger. Its function is currently not well understood, but its location close to visual areas and also to the hippocampal spatial/memory system suggest it may have a role in mediating between perceptual and memory functions,[2] particularly in the spatial domain.[3] However, its exact contribution to either space or memory processing has been hard to pin down.[4]
Contents
· 1Anatomy
· 2Neurophysiology
· 3Function
· 4Pathology
· 5Gallery
· 6References
Anatomy[edit]
This section needs expansion. You can help by adding to it.(November 2014)
There is large variation in the region's size across different species. In humans it comprises roughly 0.3% of the entire cortical surface whereas in rabbits it is at least 10%[5] and in rats it extends for more than half the cerebrum dorso-ventrally, making it one of the largest cortical regions.[2]
On the basis of its microscopic cellular structure it is divided into dysgranular (area 30) and granular (area 29) regions.[1] It has dense reciprocal projections with the visual cortex, postsubiculum (also known as dorsal presubiculum) and with anterior thalamic nuclei and the hippocampus.[6]
Neurophysiology[edit]
Neurophysiological studies of retrosplenial cortex have mainly been done in rats. Early work showed that around 8.5% of neurons in the retrosplenial cortex are head direction cells while other neurons have correlated with movement parameters such as spatial location and running speed.[7][8] Recent studies have shown that retrosplenial neuronal activity reflects multiple parameters simultaneously including which environment the animal is currently in,[9] its spatial position in the environment,[10][9] its current head direction and running speed,[9] as well as whether the animal is turning[10] or plans to turn in the future.[11] Many of these features of retrosplenial neurophysiology develop slowly as the animal learns to navigate within an environment,[11] consistent with the idea that the retrosplenial cortex participates in the long-term storage of spatial memory.[12]
Function[edit]
In humans, fMRI studies implicate the retrosplenial cortex in a wide range of cognitive functions including episodic memory, navigation, imagining future events and processing scenes more generally.[2][13] Rodent studies suggest the region is important for using surrounding visual cues to carry out these tasks.[12][14][15][16] Retrosplenial cortex is particularly responsive to permanent, non-moving environmental landmarks[17][18] and is also implicated in using them to make spatial judgements.[19][20]
(可能这里的permanent, non-moving environmental landmarks指的是对某事物的绝对信任，比如前面悬崖上的一块石头，我如果信任它稳定的话我就会敢于站上面，甚至蹦跳，这种感觉应该就是dorsal visual stream视觉信息通过retrosplenial cortex来实现的吧，应该是起到激发serotonin降低NE的作用，所谓的十分的信任那种感觉，也就是retrosplenial cortex的兴奋可以提高serotonin浓度？。但是如果，NE浓度过高，NE很容被放大，那就是不信任而慌乱的结果。而且retrosplenial cortex是在NE浓度容易被激发的环境中被兴奋才会起到很好的作用，恐高的人恐怕就是没有及时激发retrosplenial cortex吧？retrosplenial cortex好像是第一个能够提高serotonin浓度的皮层，那么能对“信任”记忆强化的递质只有acetylcholine，那就是nucleus basalis，也就是那种厚重、深深的信任感源自于serotonin浓度高与nucleus basalis对retrosplenial cortex的强烈影响，从而通过acetylcholine强化了皮层-anterior thalamus之间的连接关系。因此，当nucleus basalis萎缩时，retrosplenial cortex与anterior thalamus形成的记忆关系最先消失，那些形成笃定记忆的能力最先消失。或许retrosplenial cortex是真实宫殿记忆模式中的那个框架？)
It has also been suggested that retrosplenial cortex may translate between egocentric (self-centred) and allocentric (world-centred) spatial information, based upon its anatomical location between the hippocampus (where there are allocentric place cell representations) and the parietal lobe (which integrates egocentric sensory information).[12][21][22]
Competitors in the World Memory Championships are able to perform outstanding feats of memory and show increased fMRI activation in their retrosplenial cortex than normal controls when doing so.[23] This is thought to be due to their use of a spatial learning strategy or mnemonic device known as the method of loci.
The region also displays slow-wave theta rhythmicity[24] and when people retrieve autobiographical memories, there is theta band interaction between the retrosplenial cortex and the medial temporal lobe.[25]
Pathology[edit]
The retrosplenial cortex is one of several brain areas that produces both an anterograde and retrograde amnesia when damaged.[26] People with lesions involving the retrosplenial cortex also display a form of topographical disorientation whereby they can recognise and identify environmental landmarks, but are unable to use them to orientate themselves.[2]
The retrosplenial cortex is one of the first regions to undergo pathological changes in Alzheimer's disease and its prodromal phase of mild cognitive impairment.[27][28][29] There are also experimental findings showing that layer 5 of the retrosplenial cortex is likely responsible for dissociative states of consciousness in mammals.[30]
