WordNet

closely and firmly united or packed together; "compact soil"; "compact clusters of flowers"
a small and economical car (同)compact car
a small cosmetics case with a mirror; to be carried in a womans purse (同)powder compact
having a short and solid form or stature; "a wrestler of compact build"; "he was tall and heavyset"; "stocky legs"; "a thickset young man" (同)heavyset, stocky, thick, thickset
have the property of being packable or of compacting easily; "This powder compacts easily"; "Such odd-shaped items do not pack well" (同)pack
make a score (on a hole) equal to par
(golf) the standard number of strokes set for each hole on a golf course, or for the entire course; "a par-5 hole"; "par for this course is 72"
a thin fragment or slice (especially of wood) that has been shaved from something (同)sliver, shaving
(usually plural) a part of a fruit or vegetable that is pared or cut off; especially the skin or peel; "she could peel an apple with a single long paring"

PrepTutorEJDIC

『ぎっしり詰まった』,目詰んだ,緊密な;(体格が)引き締まった / こぢんまりして経済的な,小さくまとまった / (文体などが)簡潔な / …'を'ぎっしり詰める;…'を'圧縮する / コンパクト(鏡,おしろい,ぱふの携帯用ケース) / 中型自動車(compact car)
契約,盟約 / (…と)契約する《+『with』+『名』》
〈U〉同等,同価,同水準,同程度 / (また『par value』)〈U〉平価,額面価格 / 〈U〉(程度・質・状態・数量などの)平均,標準;(精神・健康などの)常態 / 〈C〉(ゴルフで)標準打数,パー / 《名詞の前にのみ用いて》平均の,標準の / 額面の
(ゴルフで)〈1ホールまたは1コース〉‘を'基準打数でとる,パーで上がる
〈U〉(皮を)むくこと,削ること / 〈C〉《複数形で》むいた皮,削りくず
とうちゃん(papa)

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2016/02/18 02:30:58」(JST)

wiki en

The pars compacta is a portion of the substantia nigra, located in midbrain. It is formed by dopaminergic neurons and located medial to pars reticulata. Parkinson's disease is characterized by the death of dopaminergic neurons in this region.^[1]

Anatomy

In humans, the nerve cell bodies of the pars compacta are coloured black by the pigment neuromelanin. The degree of pigmentation increases with age. This pigmentation is visible as a distinctive black stripe in brain sections and is the origin of the name given to this volume of the brain. The neurons have particularly long and thick dendrites (François et al.). The ventral dendrites, particularly, go down deeply in the pars reticulata. Other similar neurons are more sparsely distributed in the midbrain and constitute "groups" with no well-defined borders, although continuous to the pars compacta, in a prerubral position. These have been given, in early works in rats (with not much respect for the anatomical subdivisions), the name of "area A8" and "A10". The pars compacta itself ("A9") is usually subdivided into a ventral and a dorsal tier, the last being calbindin positive.^[2] The ventral tier is considered as A9v. The dorsal tier A9d is linked to an ensemble comprising also A8 and A10,^[3] A8, A9d and A10 representing 28% of dopaminergic neurons. The long dendrites of compacta neurons receive striatal information. This cannot be the case for the more posterior groups that are located outside the striato-pallidonigral bundle territory. Neurons of the pars compacta receive inhibiting signals from the collateral axons from the neurons of the pars reticulata.^[4] All these neurons send their axons along the nigrostriatal pathway to the striatum where they release the neurotransmitter dopamine. There is an organization in which dopaminergic neurons of the fringes (the lowest) go to the sensorimotor striatum and the highest to the associative striatum. Dopaminergic axons also innervate other elements of the basal ganglia system including the lateral and medial pallidum,^[5] substantia nigra pars reticulata, and the subthalamic nucleus.^[6]

Function

The function of the dopamine neurons in the substantia nigra pars compacta (SNc) is complex. Contrary to what was initially believed, SNC neurons do not directly stimulate movement: instead, it plays an indirect role by regulating the more direct role of the striatum, contributing to fine motor control, as has been confirmed in animal models with SNc lesions.^[7] Thus, electrical stimulation of the substantia nigra does not result in movement, but lack of pars compacta neurons has a large influence on movement, as evidenced by the symptoms of Parkinson's disease.

"Dopamine neurons are activated by novel, unexpected stimuli, by primary rewards in the absence of predictive stimuli and during learning".^[8] Dopamine neurons are thought to be involved in learning to predict which behaviours will lead to a reward (for example food or sex). In particular, it is suggested that dopamine neurons fire when a reward is greater than that previously expected; a key component of many reinforcement learning models. This signal can then be used to update the expected value of that action. Many recreational drugs, such as cocaine, mimic this reward response—providing an explanation for their addictive nature.

Pathology

Degeneration of pigmented neurons in this region is the principal pathology that underlies Parkinson's disease and this depigmentation can be visualized in vivo with Neuromelanin MRI.^[9] In a few people, the cause of Parkinson's disease is genetic, but in most cases, the reason for the death of these dopamine neurons is unknown. Parkinsonism can also be produced by viral infections such as encephalitis or a number of toxins, such as MPTP, an industrial toxin which can be mistakenly produced during synthesis of the meperidine analog MPPP. Many such toxins appear to work by producing reactive oxygen species. Binding to neuromelanin by means of charge transfer complexes may concentrate radical-generating toxins in the substantia nigra.

Pathological changes to the dopaminergic neurons of the pars compacta are also thought to be involved in schizophrenia (see the dopamine hypothesis of schizophrenia) and psychomotor retardation sometimes seen in clinical depression.

References

^ Kim, S. J.; Sung, JY; Um, JW; Hattori, N; Mizuno, Y; Tanaka, K; Paik, SR; Kim, J; Chung, KC (2003). "Parkin Cleaves Intracellular -Synuclein Inclusions via the Activation of Calpain". Journal of Biological Chemistry 278 (43): 41890–9. doi:10.1074/jbc.M306017200. PMID 12917442.
^ Francois, C.; Yelnik, J.; Tande, D.; Agid, Y. & Hirsch, E.C. (1999). "Dopaminergic cell group A8 in the monkey: anatomical organization and projections to the striatum". Journal of Comparative Neurology 414 (3): 334–347. doi:10.1002/(SICI)1096-9861(19991122)414:3<334::AID-CNE4>3.0.CO;2-X. PMID 10516600.
^ Feigenbaum Langer, L.; Jimenez-Castellanos, J. & Graybiel, A.M. (1991). "The substantia nigra and its relations with the striatum in the monkey". Progress in Brain Research 87: 81–99. doi:10.1016/S0079-6123(08)63048-4. PMID 1678193.
^ Hajos, M. & Greenfield, S.A. (1994). "Synaptic connections between pars compacta and pars reticulata neurones: electrophysiological evidence for functional modules within the substantia nigra". Brain Research 660 (2): 216–224. doi:10.1016/0006-8993(94)91292-0. PMID 7820690.
^ Lavoie, B., Smith, Y., Parent, A. (1989). "Dopaminergic innervation of the basal ganglia in the squirrel monkey as revealed by tyrosine hydroxylase immunohistochemistry". The Journal of Comparative Neurology 289 (1): 36–52. doi:10.1002/cne.902890104. PMID 2572613.
^ Cragg S.J.; Baufreton J.; Xue Y.; Bolam J.P.; & Bevan M.D. (2004). "Synaptic release of dopamine in the subthalamic nucleus". European Journal of Neuroscience 20 (7): 1788–1802. doi:10.1111/j.1460-9568.2004.03629.x. PMID 15380000.
^ Pioli, E.Y.; Meissner, W.; Sohr, R.; Gross, C.E.; Bezard, E.; Bioulac, B.H. (2008). "Differential behavioral effects of partial bilateral lesions of ventral tegmental area or substantia nigra pars compacta in rats". Neuroscience 153 (4): 1213–24. doi:10.1016/j.neuroscience.2008.01.084. PMID 18455318.
^ Schultz, W. (1992). "Activity of dopamine neurons in the behaving primate". Seminar in Neuroscience 4 (2): 129–138. doi:10.1016/1044-5765(92)90011-P.
^ Sasaki M, Shibata E, Tohyama K, Takahashi J, Otsuka K, Tsuchiya K, Takahashi S, Ehara S, Terayama Y, Sakai A (July 2006). "Neuromelanin magnetic resonance imaging of locus ceruleus and substantia nigra in Parkinson's disease". NeuroReport 17 (11): 1215–8. doi:10.1097/01.wnr.0000227984.84927.a7. PMID 16837857.

UpToDate Contents

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1. パーキンソン病の病因および発症機序 etiology and pathogenesis of parkinson disease
2. 小児における運動減少性運動障害 bradykinetic movement disorders in children
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4. 小児における運動過多な運動障害 hyperkinetic movement disorders in children
5. 原発性眼障害関連の網膜血管炎 retinal vasculitis associated with primary ocular disorders

English Journal

Biochemical protective effect of 1,25-dihydroxyvitamin D3 through autophagy induction in the MPTP mouse model of Parkinson's disease.

Li H1, Jang W, Kim HJ, Jo KD, Lee MK, Song SH, Yang HO.
Neuroreport.Neuroreport.2015 Aug 19;26(12):669-74. doi: 10.1097/WNR.0000000000000401.
In our previous study, the neuroprotective effect of calcitriol was confirmed in SH-SY5Y cells. In this article, we explored whether calcitriol showed neuroprotection in a subchronic 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mouse model of Parkinson's disease. After mice were treat
PMID 26164453

Methodology and effects of repeated intranasal delivery of DNSP-11 in a rat model of Parkinson's disease.

Stenslik MJ1, Potts LF1, Sonne JW1, Cass WA1, Turchan-Cholewo J1, Pomerleau F1, Huettl P1, Ai Y1, Gash DM1, Gerhardt GA1, Bradley LH2.
Journal of neuroscience methods.J Neurosci Methods.2015 Aug 15;251:120-9. doi: 10.1016/j.jneumeth.2015.05.006. Epub 2015 May 18.
BACKGROUND: To circumvent the challenges associated with delivering large compounds directly to the brain for the treatment of Parkinson's disease (PD), non-invasive procedures utilizing smaller molecules with protective and/or restorative actions on dopaminergic neurons are needed.NEW METHOD: We de
PMID 25999268

The novel mitochondrial iron chelator 5-((methylamino)methyl)-8-hydroxyquinoline protects against mitochondrial-induced oxidative damage and neuronal death.

Mena NP1, García-Beltrán O2, Lourido F3, Urrutia PJ3, Mena R3, Castro-Castillo V4, Cassels BK5, Núñez MT3.
Biochemical and biophysical research communications.Biochem Biophys Res Commun.2015 Aug 7;463(4):787-92. doi: 10.1016/j.bbrc.2015.06.014. Epub 2015 Jun 5.
Abundant evidence indicates that iron accumulation, oxidative damage and mitochondrial dysfunction are common features of Huntington's disease, Parkinson's disease, Friedreich's ataxia and a group of disorders known as Neurodegeneration with Brain Iron Accumulation. In this study, we evaluated the e
PMID 26051278

Japanese Journal

3D neuromelanin-sensitive magnetic resonance imaging with semi-automated volume measurement of the substantia nigra pars compacta for diagnosis of Parkinson's disease

Ogisu Kimihiro,Kudo Kohsuke,Sasaki Makoto,Sakushima Ken,Yabe Ichiro,Sasaki Hidenao,Terae Satoshi,Nakanishi Mitsuhiro,Shirato Hiroki
Neuroradiology 55(6), 719-724, 2013-06
… Neuromelanin-sensitive MRI has been reported to be used in the diagnosis of Parkinson's disease (PD), which results from loss of dopamine-producing cells in the substantia nigra pars compacta (SNc). …
NAID 120005460239

Roles of FGF20 in dopaminergic neurons and Parkinson's disease.

Itoh Nobuyuki,Ohta Hiroya
Frontiers in molecular neuroscience 6, 2013-05
… Fgf20 was originally identified as a new Fgf preferentially expressed in the substantia nigra pars compacta (SNpc). …
NAID 120005289845

Ablation of rat substantia nigra may provide a good acute model of Parkinson's disease for stem cell transplantation

Hirano Shun-ichiro,Ohashi Momoka,Kakihara Rina,Suwabe Takeshi,Fujimoto Tetsuya,Inoue Hiroshi,Uchihashi Kenji,Nishikawa Yasuo
Journal of Osaka Dental University 47(1), 11-19, 2013-04
… Using a stereotactic technique, we created a novel, acute model of Parkinson's disease (PD) in 45 female rats by high-frequency electric ablation of bilateral substantia nigra pars compacta with a high-frequency electric coagulator. …
NAID 110009603274

Related Pictures

★リンクテーブル★

リンク元	「黒質」「黒質緻密部」「黒質緻密層」
関連記事	「compact」「par」「nigra」「compacta」

「黒質」

Pars compacta
Details
Part of	substantia nigra
Identifiers
Latin	Pars compacta substantiae nigrae
NeuroNames	hier-528
NeuroLex ID	Substantia nigra pars compacta
	Anatomical terms of neuroanatomy [edit on Wikidata]