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）』「2013/01/16 00:36:50」(JST)
[Wiki en表示]
| Brain: Pars compacta |
| Gray's |
subject #188 802 |
| NeuroNames |
hier-528 |
The pars compacta is a portion of the substantia nigra.
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Contents
- 1 Anatomy
- 2 Function
- 3 Pathology
- 4 References
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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 mesencephalon 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.[1] The ventral tier is considered as A9v. The dorsal tier A9d is linked to an ensemble comprising also A8 and A10,[2] 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.[3] 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,[4] substantia nigra pars reticulata, and the subthalamic nucleus.[5]
Function
The function of the dopamine neurons in the substantia nigra pars compacta is complex. Contrary to what was thought initially it is not directly linked to movements. "Dopamine neurons are activated by novel, unexpected stimuli, by primary rewards in the absence of predictive stimuli and during learning".[6] 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 drugs of abuse, 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. 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
- ^ 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.
- ^ 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.
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Human brain: mesencephalon (midbrain) (TA A14.1.06, GA 9.800)
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Tectum
(Dorsal) |
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Surface
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Corpora quadrigemina: Inferior colliculi (Brachium of inferior colliculus), Superior colliculi (Brachium of superior colliculus)
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Grey matter
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Pretectal area
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White: Sensory/ascending
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Spinotectal tract · Central tegmental tract
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White: Motor/descending
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Tectospinal tract
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Peduncle
(Ventral) |
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Tegmentum
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White: Sensory/ascending
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lemnisci (Medial, Lateral) · Ascending MLF (Vestibulo-oculomotor fibers) · Spinothalamic tract · Anterior trigeminothalamic tract · Dentatothalamic tract
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White: Motor/descending
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Rubrospinal tract · Rubro-olivary tract · Descending MLF
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Grey: cranial nuclei
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GSA (V: Mesencephalic) - GSE (III: Oculomotor, IV: Trochlear) - GVE (III: Edinger-Westphal)
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Grey: other
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Periaqueductal gray/Raphe nuclei (Dorsal raphe nucleus)
Ventral tegmental area • Pedunculopontine nucleus • Red nucleus
riMLF
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Ventricular system
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Cerebral aqueduct
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Base
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White: Motor/descending
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Cerebral crus: Corticospinal tract · Corticobulbar tract · Corticopontine tract/Frontopontine fibers/Temporopontine fibers
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Grey: Substantia nigra
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Pars compacta · Pars reticulata
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Surface
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Superior cerebellar peduncle (Decussation of superior cerebellar peduncles) · Interpeduncular fossa
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anat (n/s/m/p/4/e/b/d/c/a/f/l/g)/phys/devp
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noco (m/d/e/h/v/s)/cong/tumr, sysi/epon, injr
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proc, drug (N1A/2AB/C/3/4/7A/B/C/D)
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Brain and spinal cord: neural tracts and fasciculi
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Sensory/
ascending |
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PCML
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1°: Pacinian corpuscle/Meissner's corpuscle → Gracile fasciculus/Cuneate fasciculus → Gracile nucleus/Cuneate nucleus
2°: → sensory decussation/arcuate fibers (Posterior external arcuate fibers, Internal arcuate fibers) → Medial lemniscus/Trigeminal lemniscus → Thalamus (VPL, VPM)
3°: → Posterior limb of internal capsule → Postcentral gyrus
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Anterolateral/
pain
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Fast/lateral
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1° (Free nerve ending → A delta fiber) → 2° (Anterior white commissure → Lateral and Anterior Spinothalamic tract → Spinal lemniscus → VPL of Thalamus) → 3° (Postcentral gyrus) → 4° (Posterior parietal cortex)
2° ( Spinotectal tract → Superior colliculus of Midbrain tectum)
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Slow/medial
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1° (Group C nerve fiber → Spinoreticular tract → Reticular formation) → 2° (MD of Thalamus) → 3° (Cingulate cortex)
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Motor/
descending |
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Pyramidal
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flexion: Primary motor cortex → Posterior limb of internal capsule → Decussation of pyramids → Corticospinal tract (Lateral, Anterior) → Neuromuscular junction
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Extrapyramidal
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flexion: Primary motor cortex → Genu of internal capsule → Corticobulbar tract → Facial motor nucleus → Facial muscles
flexion: Red nucleus → Rubrospinal tract
extension: Vestibulocerebellum → Vestibular nuclei → Vestibulospinal tract
extension: Vestibulocerebellum → Reticular formation → Reticulospinal tract
Midbrain tectum → Tectospinal tract → muscles of neck
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Basal ganglia
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direct: 1° (Motor cortex → Striatum) → 2° (GPi) → 3° (Lenticular fasciculus/Ansa lenticularis → Thalamic fasciculus → VL of Thalamus) → 4° (Thalamocortical radiations → Supplementary motor area) → 5° (Motor cortex)
indirect: 1° (Motor cortex → Striatum) → 2° (GPe) → 3° (Subthalamic fasciculus → Subthalamic nucleus) → 4° (Subthalamic fasciculus → GPi) → 5° (Lenticular fasciculus/Ansa lenticularis → Thalamic fasciculus → VL of Thalamus) → 6° (Thalamocortical radiations → Supplementary motor area) → 7° (Motor cortex)
nigrostriatal pathway: Pars compacta → Striatum
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| Cerebellar |
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Afferent
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Vestibular nucleus → Vestibulocerebellar tract → ICP → Cerebellum → Granule cell
Pontine nuclei → Pontocerebellar fibers → MCP → Deep cerebellar nuclei → Granule cell
Inferior olivary nucleus → Olivocerebellar tract → ICP → Hemisphere → Purkinje cell → Deep cerebellar nuclei
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Efferent
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Dentate nucleus in Lateral hemisphere/pontocerebellum → SCP → Dentatothalamic tract → Thalamus (VL) → Motor cortex
Interposed nucleus in Intermediate hemisphere/spinocerebellum → SCP → Reticular formation, or → Cerebellothalamic tract → Red nucleus → Thalamus (VL) → Motor cortex
Fastigial nucleus in Flocculonodular lobe/vestibulocerebellum → Vestibulocerebellar tract → Vestibular nucleus
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Bidirectional:
Spinocerebellar
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Unc. prop.
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lower limb → 1° (muscle spindles → DRG) → 2° (Posterior thoracic nucleus → Dorsal/posterior spinocerebellar tract → ICP → Cerebellar vermis)
upper limb → 1° (muscle spindles → DRG) → 2° (Accessory cuneate nucleus → Cuneocerebellar tract → ICP → Anterior lobe of cerebellum)
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Reflex arc
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lower limb → 1° (Golgi tendon organ) → 2° (Ventral/anterior spinocerebellar tract→ SCP → Cerebellar vermis)
upper limb → 1° (Golgi tendon organ) → 2° ( Rostral spinocerebellar tract → ICP → Cerebellum)
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anat (n/s/m/p/4/e/b/d/c/a/f/l/g)/phys/devp
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noco (m/d/e/h/v/s)/cong/tumr, sysi/epon, injr
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proc, drug (N1A/2AB/C/3/4/7A/B/C/D)
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anat (h/r/t/c/b/l/s/a)/phys (r)/devp/prot/nttr/nttm/ntrp
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noco/auto/cong/tumr, sysi/epon, injr
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UpToDate Contents
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English Journal
- Age and duration of inflammatory environment differentially affect the neuroimmune response and catecholaminergic neurons in the midbrain and brainstem.
- Bardou I1, Kaercher RM1, Brothers HM1, Hopp SC1, Royer S1, Wenk GL2.Author information 1Department of Psychology, The Ohio State University, Columbus, OH, USA; Department of Neuroscience, The Ohio State University, Columbus, OH, USA.2Department of Psychology, The Ohio State University, Columbus, OH, USA; Department of Neuroscience, The Ohio State University, Columbus, OH, USA. Electronic address: wenk.6@osu.edu.AbstractNeuroinflammation and degeneration of ascending catecholaminergic systems occur early in the neurodegenerative process. Age and the duration of a pro-inflammatory environment induced by continuous intraventricular lipopolysaccharide (LPS) differentially affect the expression profile of pro- and anti-inflammatory genes and proteins as well as the number of activated microglia (express major histocompatibility complex II; MHC II) and the integrity and density of ascending catecholaminergic neural systems originating from the locus coeruleus (LC) and substantia nigra pars compacta (SNpc) in rats. LPS infusion increased gene expression and/or protein levels for both pro- and anti-inflammatory biomarkers. Although LPS infusion stimulated a robust increase in IL-1ß gene and protein expression, this increase was blunted with age. LPS infusion also increased the density of activated microglia cells throughout the midbrain and brainstem. Corresponding to the development of a pro-inflammatory environment, LC and SNpc neurons immunopositive for tyrosine-hydroxylase (the rate-limiting synthetic enzyme for dopamine and norepinephrine) decreased in number, along with a decrease in tyrosine-hydroxylase gene expression in the midbrain and/or brainstem region. Our data support the concept that continuous exposure to a pro-inflammatory environment drives exaggerated changes in the production and release of inflammatory mediators that interact with age to impair functional capacity of the SNpc and LC.
- Neurobiology of aging.Neurobiol Aging.2014 May;35(5):1065-73. doi: 10.1016/j.neurobiolaging.2013.11.006. Epub 2013 Nov 19.
- Neuroinflammation and degeneration of ascending catecholaminergic systems occur early in the neurodegenerative process. Age and the duration of a pro-inflammatory environment induced by continuous intraventricular lipopolysaccharide (LPS) differentially affect the expression profile of pro- and anti
- PMID 24315728
- Chronic l-DOPA treatment attenuates behavioral and biochemical deficits induced by unilateral lactacystin administration into the rat substantia nigra.
- Konieczny J1, Czarnecka A2, Lenda T2, Kamińska K2, Lorenc-Koci E2.Author information 1Department of Neuropsychopharmacology, Institute of Pharmacology, Polish Academy of Sciences, Smętna 12 Street, PL 31-343 Kraków, Poland. Electronic address: koniecz@if-pan.krakow.pl.2Department of Neuropsychopharmacology, Institute of Pharmacology, Polish Academy of Sciences, Smętna 12 Street, PL 31-343 Kraków, Poland.AbstractThe aim of the study was to determine whether the dopamine (DA) precursor l-DOPA attenuates parkinsonian-like symptoms produced by the ubiquitin-proteasome system inhibitor lactacystin. Wistar rats were injected unilaterally with lactacystin (2.5μg/2μl) or 6-OHDA (8μg/2μl) into the substantia nigra (SN) pars compacta. Four weeks after the lesion, the animals were treated chronically with l-DOPA (25 or 50mg/kg) for two weeks. During l-DOPA treatment, the lactacystin-treated rats were tested for catalepsy and forelimb asymmetry. Rotational behavior was evaluated after apomorphine (0.25mg/kg) and l-DOPA in both PD models. After completion of experiments, the animals were killed and the levels of DA and its metabolites in the striatum and SN were assayed. We found that acute l-DOPA administration effectively decreased catalepsy and increased the use of the compromised forelimb in the cylinder test. However, the lactacystin group did not respond to apomorphine or acute l-DOPA administration in the rotational test. Repeated l-DOPA treatment produced contralateral rotations in both PD models, but the number of rotations was much greater in the 6-OHDA-lesioned rats. Both toxins markedly (>90%) reduced the levels of DA and its metabolites in the striatum and SN, while l-DOPA diminished these decreases, especially in the SN. By demonstrating the efficacy of l-DOPA in several behavioral tests, our study confirms the usefulness of the lactacystin lesion as a model of PD. However, marked differences in the rotational response to apomorphine and l-DOPA suggest different mechanisms of neurodegeneration evoked by lactacystin and 6-OHDA.
- Behavioural brain research.Behav Brain Res.2014 Mar 15;261:79-88. doi: 10.1016/j.bbr.2013.12.019. Epub 2013 Dec 17.
- The aim of the study was to determine whether the dopamine (DA) precursor l-DOPA attenuates parkinsonian-like symptoms produced by the ubiquitin-proteasome system inhibitor lactacystin. Wistar rats were injected unilaterally with lactacystin (2.5μg/2μl) or 6-OHDA (8μg/2μl) into the substantia ni
- PMID 24361083
Japanese Journal
- 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 Links
- In addition, by treating JNK with a peptide inhibitor derived from a mitochondrial membrane protein, the team was able to induce a two-fold level of protection of neurons in the substantia nigra pars compacta, the brain region devastated ...
- The pars compacta is a portion of the substantia nigra. Anatomy The pars compacta contains neurons which, in humans, are coloured black by the pigment neuromelanin that increases with age. This pigmentation is visible as a ...
Related Pictures
★リンクテーブル★
[★]
- 英
- (n
- 関
- 緻密層
[★]
緻密層、緻密部
- 関
- compact layer、pars compacta
[★]
- 関
- compactly
[★]
- →para
[★]
