線條體

出自維基百科,自由嘅百科全書
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Striatum.svg

線條體striatum / corpus striatum)係喺個基底核嘅一柞神經細胞。專管動機相關嘅功能。

同犒賞系統嘅啦掕[編輯]

  • 腹側線條體(ventral striatum),包括伏隔核(nucleus accumbens,NAc):NAc 由 VTA訊號嗰陣會幫手學習新嘅行為,而由前額皮層收訊號嗰陣會幫手引起行為。NAc 喺隻動物做緊有犒賞性嘅行為嗰時會啟動,而且 NAc 零舍會對自然犒賞-指嘢食同性愛等唔使學隻動物都知係犒賞嘅嘢-有強烈嘅多巴胺反應;NAc 仲同上癮嘅現象好有啦掕-喺正常情況下,NAc 嘅多巴胺反應會隨住隻動物一再噉攞到件犒賞而減弱[1],但多種嘅毒品都能夠阻止呢種反應減弱,即係個人就算一再噉吸毒品,NAc 嘅多巴胺反應都唔減弱,而呢點俾人話係「對毒品上癮嘅人想係噉一再吸毒」嘅主因之一[2][3]
  • 背側線條體(dorsal striatum,DS):DS 同「學識對件犒賞有反應」零舍有啦掕;當一隻動物持續噉接觸到一件犒賞,NAc 同 DS 之間會產生一個訊號迴圈,令到 NAc 能夠喺件犒賞唔實際存在嘅情境下啟動 DS 嘅反應,簡單講即係話 DS 令個人能夠喺接觸過件犒賞幾次之後,就開始能夠靠喺腦海入面憑空想像件犒賞嚟引起身體嘅「搵犒賞」反應,即係例如一個人,佢食過一味好食嘅餸菜食過幾次,跟住佢變到一諗起味餸菜就開胃,並且因此而會主動噉去搵味餸菜嚟食。因為呢個緣故,DS 俾人指同渴求(craving)好有關係,會搞到一個毒品上癮嘅人因為「係噉喺腦海入面想像件毒品曾經令自己幾咁興奮」而主動想要去搵件毒品[4][5]

睇埋[編輯]

[編輯]

  1. Rada, P., Avena, N. M., & Hoebel, B. G. (2005). Daily bingeing on sugar repeatedly releases dopamine in the accumbens shell. Neuroscience, 134(3), 737-744.
  2. Pothos, E., Rada, P., Mark, G. P., & Hoebel, B. G. (1991). Dopamine microdialysis in the nucleus accumbens during acute and chronic morphine, naloxone-precipitated withdrawal and clonidine treatment. Brain research, 566(1-2), 348-350.
  3. Salgado, S., & Kaplitt, M. G. (2015). The nucleus accumbens: a comprehensive review (PDF). Stereotactic and functional neurosurgery, 93(2), 75-93.
  4. Yin, H. H., Knowlton, B. J., & Balleine, B. W. (2005). Blockade of NMDA receptors in the dorsomedial striatum prevents action–outcome learning in instrumental conditioning. European Journal of Neuroscience, 22(2), 505-512.
  5. Nummenmaa, L., Hirvonen, J., Hannukainen, J. C., Immonen, H., Lindroos, M. M., Salminen, P., & Nuutila, P. (2012). Dorsal striatum and its limbic connectivity mediate abnormal anticipatory reward processing in obesity. PloS one, 7(2), e31089.