medial geniculate nucleus

内側膝状核 MGN

WordNet

1. a part of the cell containing DNA and RNA and responsible for growth and reproduction (同)cell_nucleus, karyon
2. (astronomy) the center of the head of a comet; consists of small solid particles of ice and frozen gas that vaporizes on approaching the sun to form the coma and tail
3. any histologically identifiable mass of neural cell bodies in the brain or spinal cord
4. the positively charged dense center of an atom
5. dividing an animal into right and left halves (同)median
6. bent at a sharp angle

PrepTutorEJDIC

1. 中心,核 / (生物の)細胞核 / 原子核
2. 中間の,中間に位置する / 平均の,並なみの
3. mediumの複数形

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/03/04 04:39:19」(JST)

wiki en

[Wiki en表示]

Brain: Medial geniculate 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
auditory pathway (Medial geniculate body labeled at upper right, second from top)
Latin	corpus geniculatum mediale
Gray's	subject #188 806
Part of	Thalamus
System	Auditory system
Artery	Striata
NeuroNames	hier-338
NeuroLex ID	birnlex_1670

The medial geniculate nucleus (MGN) or medial geniculate body (MGB) is part of the auditory thalamus and represents the thalamic relay between the inferior colliculus (IC) and the auditory cortex (AC). It is made up of a number of sub-nuclei that are distinguished by their neuronal morphology and density, by their afferent and efferent connections, and by the coding properties of their neurons. It is thought that the MGB influences the direction and maintenance of attention.

Divisions

The MGB has three major divisions; ventral (VMGB), dorsal (DMGB) and medial (MMGB). Whilst the VMGB is specific to auditory information processing, the DMGB and MMGB also receive information from non-auditory pathways.

aaa	Inputs	Outputs
VMGB	* Inferior colliculus ICC (ipsilateral) ICP (contralateral) Reticular nucleus of the thalamus (ipsilateral) Auditory cortex	Auditory cortex Anterior (AAF) Primary (AI) Posterior (PAF)
DMGB	* IC Pericentral nuclei External nuclei Auditory cortex Other thalamic nuclei	Auditory cortex
MMGB	* ICC (ipsilateral) LLN (ipsi and contra) Superior colliculus Periolivary nuclei Auditory cortex Secondary (AII) Reticular nucleus of thalamus Somatosensory and vestibular influences are also present	Auditory Cortex AII (ipsilateral) AAF (ipsilateral) AI (ipsilateral) PAF (ipsilateral)

VMGB: ventral subnucleus of the medial geniculate body

Cell types

There are two main VMGB cell types:

• Thalamocortical relay cells (a.k.a. principal neurons): The dendritic input to these cells comes from two sets of dendritic trees oriented on opposite poles of the cell. The long axis of the relay cells lie parallel to each other running superior-inferiorly with the dendritic trees of cells within the same iso-frequency band overlapping. This is similar to the dendritic organization of the ICC, but with a different orientation. The dendrites of relay cells form a synaptic nest with ascending axons from the IC and intrathalamic interneurons. In this synapse, relay cells are excited by input from the IC axons. At the same time, they are inhibited by dendritodendritic synapses from the interneurons of the VMGB. This type of synaptic nesting is characteristic of other regions in the thalamus as well.

• Intrathalamic Interneurons: These interneurons provide inhibitory (GABA) input to the relay cells at the synaptic nests. The target of their axons however, is not clear. Some interneurons appear to target relay cells, while others target other interneurons. There is also at least one type of interneuron that appears to not be involved in the synaptic nests.

Function

The VMGB is thought to be primarily responsible for relaying frequency, intensity and binaural information to the cortex. The responses in the VMGB appear to be organized in a tonotopically similar way to those in the IC. The primary difference being that the iso-frequency bands are arranged such that lateral regions are most responsive to low frequencies and medial regions are responsive to high frequencies. Spatiotopic and modulotopic maps (as in the IC) however have not been well supported by mammalian studies. Both monaural (10%) and binaural cells (90%) exist in the MGB. The monaural cells are primarily responsive to sound in the contralateral hemifield. Binaural cells are typically similar to the EE or EI type found in the IC.

DMGB: dorsal subnucleus of the medial geniculate body

Cell types

There are a large number of cell types present in the DMGB:

At least two principal cell types have been found, along with two distinct types of interneurons. Several sub-nuclei have been identified based on morphology. No frequency-specific layering has been found in the DMGB.

Function

Many types of responses are present in the DMGB that appear to vary by sub-nuclei. Generally, the responses are broadly tuned, but some cells appear to respond only to complex stimuli. Other cells are multi modal, often responding to somatosensory as well as auditory stimuli.

MMGB: medial subnucleus of the medial geniculate body

Cell Types

Cells in the MMGB have large irregular shaped dendritic trees. There is no clear segregation based on the source of these inputs.

Function

The MMGB seems to functionally be responsible for detection of the relative intensity and duration of a sound. It shows a wide range of responses to auditory stimuli. Binaural interactions found in the MMGB include EE, EI, and IE types. Both broadly and narrowly tuned cells have been observed. A type of intensity tuning has also been observed. In this type of cell, the response actually decreases as sound intensity increases above a specific level. Almost all cells in the MMGB appear to respond for the duration of the stimulus, and have very little adaptation. Individual cells still appear to be preferentially tuned to certain frequencies, but they often have more than one CF and are broadly tuned around these CF’s. It is not clear whether there truly is one, none, or many tonotopic organizations maps present in the MMGB. Anaesthetics tend to have large effects on cells within the MMGB, making responses difficult to study. Finally, the behaviour of MMGB cells are complicated by the fact that sensory stimulation from other modalities modifies the responsiveness of many, but not all, cells in the MMGB.

See also

• auditory system
• Lateral geniculate nucleus

Additional images

• Thalamus

• Deep dissection of brain-stem. Lateral view.

• Deep dissection of brain-stem. Lateral view.

• Dissection of brain-stem. Dorsal view.

• Hind- and mid-brains; postero-lateral view.

• Scheme showing central connections of the optic nerves and optic tracts.

References

• Buffalo.edu
• Brainconnection.com

External links

• Mnemonic at medicalmnemonics.com 307 640

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English Journal

• Temporal changes in calcium-binding proteins in the medial geniculate nucleus of the monkey Sapajus apella.

• Campos LM1, Osório EC1, Santos GL1, Nogueira MI2, Cruz-Rizzolo RJ3, Pinato L4.
• Journal of chemical neuroanatomy.J Chem Neuroanat.2015 Jul 26. pii: S0891-0618(15)00056-3. doi: 10.1016/j.jchemneu.2015.07.005. [Epub ahead of print]
• The subdivisions of the medial geniculate complex can be distinguished based on the immunostaining of calcium-binding proteins and by the properties of the neurons within each subdivision. The possibility of changes in neurochemistry in this and other central auditory areas are important aspects to
• PMID 26222835

• GABAergic inhibition shapes SAM responses in rat auditory thalamus.

• Cai R1, Caspary DM2.
• Neuroscience.Neuroscience.2015 Jul 23;299:146-55. doi: 10.1016/j.neuroscience.2015.04.062. Epub 2015 May 2.
• Auditory thalamus (medial geniculate body [MGB]) receives ascending inhibitory GABAergic inputs from inferior colliculus (IC) and descending GABAergic projections from the thalamic reticular nucleus (TRN) with both inputs postulated to play a role in shaping temporal responses. Previous studies sugg
• PMID 25943479

• Diffusion tensor imaging of dolphin brains reveals direct auditory pathway to temporal lobe.

• Berns GS1, Cook PF2, Foxley S3, Jbabdi S3, Miller KL3, Marino L4.
• Proceedings. Biological sciences / The Royal Society.Proc Biol Sci.2015 Jul 22;282(1811). pii: 20151203. doi: 10.1098/rspb.2015.1203.
• The brains of odontocetes (toothed whales) look grossly different from their terrestrial relatives. Because of their adaptation to the aquatic environment and their reliance on echolocation, the odontocetes' auditory system is both unique and crucial to their survival. Yet, scant data exist about th
• PMID 26156774

Japanese Journal

• A Neuron Model Capable of Learning Expansion/Contraction Movement Detection without Teacher's Signal

• Todo Yuki,Tamura Hiroki
• International Journal of Innovative Computing, Information and Control 9(12), 4931-4941, 2013
• … The proposed model consists of the retina, LGN (lateral geniculate nucleus), V1(primary visual cortex) and MST (medial superior temporal area). …
• NAID 120005345680

• 単一聴覚細胞の内側膝状体から視床網様核への投射様式--視床-大脳皮質連絡における聴覚情報処理機構の多様性

• 木村 晃久,堂西 倫弘,井辺 弘樹
• 聴覚研究会資料 39(7), 477-482, 2009-11-13
• NAID 40016937299

• Neuronal organization of the rat inferior colliculus participating in four major auditory pathways.

• Okoyama Shigeo,Ohbayashi Masao,Ito M.,Harada Shin-ichi
• Hearing Research 218(1-2), 72-80, 2006-08
• … The central nucleus of the inferior colliculus (CNIC) contains different types of neurons and is a source of ascending projection to the medial geniculate body (MGB), commissural projection to the contralateral IC, direct descending projection to the cochlea nucleus (CN) and indirect projection to the CN via the superior olivary complex (SOC). …
• NAID 120001613709

Related Links

• Medial geniculate nucleusとは - goo Wikipedia (ウィキペディア)

The medial geniculate nucleus (MGN) or medial geniculate body (MGB) is part of the auditory thalamus and represents the thalamic relay between the inferior colliculus (IC) and the auditory cortex (AC). It is made up of a number of ...

• Medial geniculate nucleus definition of Medial geniculate ...

nucleus, in biology nucleus: see cell cell, in biology, the unit of structure and function of which all plants and animals are composed. The cell is the smallest unit in the living organism that is capable of integrating the essential life ...

Related Pictures

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★リンクテーブル★

リンク元	「内側膝状体核」「内側膝状核」
関連記事	「medial」「media」「geniculate」

「内側膝状体核」

　　[★]

英

medial geniculate nucleus

関

内側膝状体

「内側膝状核」

　　[★]

英

medial geniculate nucleus, MGN

「medial」

　　[★]

• adj.

• 内側の、中心の、中央の、内側性の

関

center、central、centre、centro、centrum、hub、inner、inside、interior、medialis、medially、middle

　 　

「media」

　　[★]

• n.

関

culture、culture media、culture medium、culture solution、medium

　

「geniculate」

　　[★]

• adj.

• 膝状体の

関

geniculate body