伏隔核拉丁語nucleus accumbens;英語:accumbens nucleus,NAc,NAcc),台灣譯依核[1],又称依伏神经核,是位于基底核边缘系统交接处、尾状核头部下方的神经核团;大脑的每侧半球各有一个伏隔核,它位于尾状核头部、壳核的前部,侧面与透明隔相接;伏隔核与嗅结节组成腹侧纹状体[2]

大脑伏隔核(红色)的大致位置。丘脑为蓝色,其他相关结构为粉色。

伏隔核是大脑的愉悦中枢,参与奖赏快乐成瘾侵犯恐惧安慰剂效果等活动[3][4][5]

伏隔核核心的一部分主要参与慢波睡眠的诱导[6] [7] [8] [9],也参与新运动程序的编码[10]。伏隔核在处理恐惧(厌恶的一种形式)、冲动安慰剂效应方面发挥较小的作用[11] [12] [13]

伏隔核可以分作两部分:伏隔核的核伏隔核的壳,两个结构有不同的形态和功能。

细胞类型

伏隔核的基本细胞类型是中型多棘神经元,这类神经元产生的神经递质γ-氨基丁酸 (GABA),一种主要的中枢神经系统的抑制性神经递质,这些神经元也是伏隔核的主要投射或者称输出神经元。

隔核的95%神经元是中型多棘GABA能投射神经元,其它类型神经元还发现有无棘胆碱能中间神经元

功能之慢波睡眠

2017年底,利用光遗传学和化学遗传学方法对啮齿类动物的研究发现,伏隔核核心中共同表达腺苷A 2A受体并投射到腹侧苍白球的间接途径(即D2型)中型多棘神经元参与了慢波睡眠的调节。[14][15][16][17] 特别是,这些间接途径 NAcc 核心神经元的光遗传学激活会诱导慢波睡眠,而相同神经元的化学遗传学激活会增加慢波睡眠发作的次数和持续时间。[15][16][17] 这些 NAcc 核心神经元的化学遗传学抑制会抑制睡眠。[15][16]相反,NAcc 壳中表达腺苷 A 2A受体的 D2 型中型多棘神经元在调节慢波睡眠中没有作用。 [15][16]

输出与输入

输出

伏隔核的输出神经元发出的轴突投射到苍白球的腹侧对应部分,称作腹侧苍白球(VP),腹侧苍白球再投射到背侧丘脑背内侧核。背内侧核在投射到前额皮质纹状体,伏隔核其它输出连接还有投射到黑质桥脑网状结构

输入

伏隔核的主要输入包括前额皮质相关神经元,杏仁体基底外侧核,以及通过中脑边缘通道联系的腹侧被盖区(VTA)的多巴胺神经元。因此,伏隔核经常被描述为皮质-纹状体-丘脑-皮质回路的一部分。

从VTA的多巴胺能输入被认为调节伏隔核神经元活动。这些神经末梢是高成瘾性药品如可卡因安非他命的作用区,能引起伏隔核多巴胺浓度的大量增加。其它娱乐性药物也是在伏隔核增加多巴胺浓度。

另外一大类输入是从大脑海马的腹侧下托及CA1区到伏隔核背内侧区域。海马的神经元显然与伏隔核细胞的轻微去极化相关,使得伏隔核细胞更为正电性因而更容易激发。与海马关联的伏隔核的激发态中型多棘神经元细胞由海马下托与CA1区共享。海马下托神经元能超极化(增加负电性)而CA1神经元振荡(> 50 Hz)以完成启动。[18]

研究

1950年代,詹姆斯·奧爾茲与Peter Milner在大白鼠的隔区植入电极,发现大白鼠选择按压一个刺激该电极的开关。大白鼠持续选择此操作甚至停止了吃喝。这暗示此区域是大脑的欣快中心,然而隔核并不直接连通到伏隔核。[19]

虽然伏隔核传统上被研究在成瘾中的作用,但它在奖赏系统如食物和性等的也有重要作用。近来的研究发现伏隔核涉及由音乐调节情绪,[20] 可能是它调节多巴胺释放的结果。伏隔核对音乐的神经认知中的节奏定时有作用,并被认为在边缘-运动界面(Mogensen)有关键作用。

2007年4月,两个研究队伍报告通过在伏隔核插入电极以使用脑深层刺激治疗几种临床抑郁。[21]

2007年7月, Jon-Kar Zubieta报告伏隔核是安慰剂效应的机制中心。[22]

2012年瑞士巴塞尔大学的神经经济学教授瓦西里·克卢恰廖夫研究发现:人类在进行一项决策并选择从众的时候,会激活伏隔核,使其呈现出“欢呼雀跃”的状态。 [23]

参考文献

  1. ^ 依核. 樂詞網. 國家教育研究院.  (繁體中文)
  2. ^ Nucleus Accumbens. [2011-04-05]. (原始内容存档于2020-10-02). 
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  4. ^ The Placebo Effect in the NAC. [2011-04-05]. (原始内容存档于2014-10-18). 
  5. ^ Dopamine Involved In Aggression - Medical News Today. [2011-04-05]. (原始内容存档于2010-09-23). 
  6. ^ Cherasse Y, Urade Y. Dietary Zinc Acts as a Sleep Modulator. International Journal of Molecular Sciences. November 2017, 18 (11): 2334. PMC 5713303 . PMID 29113075. doi:10.3390/ijms18112334 . More recently, Fuller's laboratory also discovered that sleep can be promoted by the activation of a gamma-aminobutyric acid-ergic (GABAergic) population of neurons located in the parafacial zone [11,12], while the role of the GABAergic A2AR-expressing neurons of the nucleus accumbens [13] and the striatum has just been revealed [14,15]. 
  7. ^ Valencia Garcia S, Fort P. Nucleus Accumbens, a new sleep-regulating area through the integration of motivational stimuli. Acta Pharmacologica Sinica. February 2018, 39 (2): 165–166. PMC 5800466 . PMID 29283174. doi:10.1038/aps.2017.168. The nucleus accumbens comprises a contingent of neurons specifically expressing the post-synaptic A2A-receptor (A2AR) subtype making them excitable by adenosine, its natural agonist endowed with powerful sleep-promoting properties[4]. ... In both cases, large activation of A2AR-expressing neurons in NAc promotes slow wave sleep (SWS) by increasing the number and duration of episodes. ... After optogenetic activation of the core, a similar promotion of SWS was observed, whereas no significant effects were induced when activating A2AR-expressing neurons within the shell. 
  8. ^ Oishi Y, Xu Q, Wang L, Zhang BJ, Takahashi K, Takata Y, Luo YJ, Cherasse Y, Schiffmann SN, de Kerchove d'Exaerde A, Urade Y, Qu WM, Huang ZL, Lazarus M. Slow-wave sleep is controlled by a subset of nucleus accumbens core neurons in mice. Nature Communications. September 2017, 8 (1): 734. Bibcode:2017NatCo...8..734O. PMC 5622037 . PMID 28963505. doi:10.1038/s41467-017-00781-4. Here, we show that chemogenetic or optogenetic activation of excitatory adenosine A2A receptor-expressing indirect pathway neurons in the core region of the NAc strongly induces slow-wave sleep. Chemogenetic inhibition of the NAc indirect pathway neurons prevents the sleep induction, but does not affect the homoeostatic sleep rebound. 
  9. ^ Yuan XS, Wang L, Dong H, Qu WM, Yang SR, Cherasse Y, Lazarus M, Schiffmann SN, d'Exaerde AK, Li RX, Huang ZL. 2A receptor neurons control active-period sleep via parvalbumin neurons in external globus pallidus. eLife. October 2017, 6: e29055. PMC 5655138 . PMID 29022877. doi:10.7554/eLife.29055 . 
  10. ^ Malenka RC, Nestler EJ, Hyman SE. Molecular Neuropharmacology: A Foundation for Clinical Neuroscience 2nd. New York: McGraw-Hill Medical. 2009: 147–148, 367, 376. ISBN 978-0-07-148127-4. VTA DA neurons play a critical role in motivation, reward-related behavior (Chapter 15), attention, and multiple forms of memory. This organization of the DA system, wide projection from a limited number of cell bodies, permits coordinated responses to potent new rewards. Thus, acting in diverse terminal fields, dopamine confers motivational salience ("wanting") on the reward itself or associated cues (nucleus accumbens shell region), updates the value placed on different goals in light of this new experience (orbital prefrontal cortex), helps consolidate multiple forms of memory (amygdala and hippocampus), and encodes new motor programs that will facilitate obtaining this reward in the future (nucleus accumbens core region and dorsal striatum). In this example, dopamine modulates the processing of sensorimotor information in diverse neural circuits to maximize the ability of the organism to obtain future rewards. ...
    The brain reward circuitry that is targeted by addictive drugs normally mediates the pleasure and strengthening of behaviors associated with natural reinforcers, such as food, water, and sexual contact. Dopamine neurons in the VTA are activated by food and water, and dopamine release in the NAc is stimulated by the presence of natural reinforcers, such as food, water, or a sexual partner. ...
    The NAc and VTA are central components of the circuitry underlying reward and memory of reward. As previously mentioned, the activity of dopaminergic neurons in the VTA appears to be linked to reward prediction. The NAc is involved in learning associated with reinforcement and the modulation of motoric responses to stimuli that satisfy internal homeostatic needs. The shell of the NAc appears to be particularly important to initial drug actions within reward circuitry; addictive drugs appear to have a greater effect on dopamine release in the shell than in the core of the NAc.
     
  11. ^ Schwienbacher I, Fendt M, Richardson R, Schnitzler HU. Temporary inactivation of the nucleus accumbens disrupts acquisition and expression of fear-potentiated startle in rats. Brain Research. November 2004, 1027 (1–2): 87–93. PMID 15494160. S2CID 18338111. doi:10.1016/j.brainres.2004.08.037. 
  12. ^ Zubieta JK, Stohler CS. Neurobiological mechanisms of placebo responses. Annals of the New York Academy of Sciences. March 2009, 1156 (1): 198–210. Bibcode:2009NYASA1156..198Z. PMC 3073412 . PMID 19338509. doi:10.1111/j.1749-6632.2009.04424.x. 
  13. ^ Basar K, Sesia T, Groenewegen H, Steinbusch HW, Visser-Vandewalle V, Temel Y. Nucleus accumbens and impulsivity. Progress in Neurobiology. December 2010, 92 (4): 533–57. PMID 20831892. S2CID 16964212. doi:10.1016/j.pneurobio.2010.08.007. 
  14. ^ Cherasse Y, Urade Y. Dietary Zinc Acts as a Sleep Modulator. International Journal of Molecular Sciences. November 2017, 18 (11): 2334. PMC 5713303 . PMID 29113075. doi:10.3390/ijms18112334 . More recently, Fuller's laboratory also discovered that sleep can be promoted by the activation of a gamma-aminobutyric acid-ergic (GABAergic) population of neurons located in the parafacial zone [11,12], while the role of the GABAergic A2AR-expressing neurons of the nucleus accumbens [13] and the striatum has just been revealed [14,15]. 
  15. ^ 15.0 15.1 15.2 15.3 Valencia Garcia S, Fort P. Nucleus Accumbens, a new sleep-regulating area through the integration of motivational stimuli. Acta Pharmacologica Sinica. February 2018, 39 (2): 165–166. PMC 5800466 . PMID 29283174. doi:10.1038/aps.2017.168. The nucleus accumbens comprises a contingent of neurons specifically expressing the post-synaptic A2A-receptor (A2AR) subtype making them excitable by adenosine, its natural agonist endowed with powerful sleep-promoting properties[4]. ... In both cases, large activation of A2AR-expressing neurons in NAc promotes slow wave sleep (SWS) by increasing the number and duration of episodes. ... After optogenetic activation of the core, a similar promotion of SWS was observed, whereas no significant effects were induced when activating A2AR-expressing neurons within the shell. 
  16. ^ 16.0 16.1 16.2 16.3 Oishi Y, Xu Q, Wang L, Zhang BJ, Takahashi K, Takata Y, Luo YJ, Cherasse Y, Schiffmann SN, de Kerchove d'Exaerde A, Urade Y, Qu WM, Huang ZL, Lazarus M. Slow-wave sleep is controlled by a subset of nucleus accumbens core neurons in mice. Nature Communications. September 2017, 8 (1): 734. Bibcode:2017NatCo...8..734O. PMC 5622037 . PMID 28963505. doi:10.1038/s41467-017-00781-4. Here, we show that chemogenetic or optogenetic activation of excitatory adenosine A2A receptor-expressing indirect pathway neurons in the core region of the NAc strongly induces slow-wave sleep. Chemogenetic inhibition of the NAc indirect pathway neurons prevents the sleep induction, but does not affect the homoeostatic sleep rebound. 
  17. ^ 17.0 17.1 Yuan XS, Wang L, Dong H, Qu WM, Yang SR, Cherasse Y, Lazarus M, Schiffmann SN, d'Exaerde AK, Li RX, Huang ZL. 2A receptor neurons control active-period sleep via parvalbumin neurons in external globus pallidus. eLife. October 2017, 6: e29055. PMC 5655138 . PMID 29022877. doi:10.7554/eLife.29055 . 
  18. ^ The Journal of Neuroscience, 2001, 21:RC131:1-5 Synchronous Activity in the Hippocampus and Nucleus Accumbens In Vivo Yukiori Goto and Patricio O'Donnell
  19. ^ Olds J, Milner P. Positive reinforcement produced by electrical stimulation of septal area and other regions of rat brain. J Comp Physiol Psychol. 1954, 47 (6): 419–27. PMID 13233369. doi:10.1037/h0058775.  article页面存档备份,存于互联网档案馆
  20. ^ Menon, Vinod & Levitin, Daniel J. (2005) The rewards of music listening: Response and physiological connectivity of themesolimbic system." NeuroImage 28(1), pp. 175-184
  21. ^ Brain Electrodes Help Treat Depression页面存档备份,存于互联网档案馆), Technology Review, 26 April 2007
  22. ^ http://www.eurekalert.org/pub_releases/2007-07/cp-brc071607.php页面存档备份,存于互联网档案馆) Brain region central to placebo effect identified
  23. ^ Rieskamp, Jörg & Tugin, Sergei & Ossadtchi, Alexei & Krutitskaya, Janina & Klucharev, Vasily. (2012). Electrophysiological precursors of social conformity. Social cognitive and affective neuroscience. 8. 10.1093/scan/nss064.