周晗, 郭明
杏仁核抑制性神经元与焦虑的研究进展*
周晗, 郭明△
[滨州医学院附属医院(滨州医学院第一临床医学院)心理科,医学研究中心,山东 滨州 256603]
杏仁核;抑制性神经元;焦虑;光遗传学
焦虑障碍是以过度恐惧和焦虑以及行为紊乱为特征的精神疾病,全球患病率为7.3%[1],我国焦虑障碍的终身患病率已达到7.6%[2]。焦虑障碍严重影响患者的工作和生活,给社会带来巨大的疾病负担。目前关于焦虑障碍的确切发病机制尚不清楚,临床上主要应用抗抑郁药和苯二氮卓类药物进行治疗,存在起效慢、副作用大等缺点。杏仁核是恐惧、焦虑等负性情绪调控的重要脑区,当对杏仁核的抑制性调控减弱时,会导致杏仁核内部神经元活动异常兴奋,增加实验动物的焦虑样行为[3]。研究显示抑制性γ-氨基丁酸(gamma-aminobutyric acid, GABA)能系统与焦虑关系密切,杏仁核中有大量的GABA能抑制性神经元可能参与调控焦虑[4]。随着基因工程、生物信息学、光遗传学等学科和技术的发展及其在神经科学研究领域的应用,对神经元分类、分布、功能的研究不断深入,对抑制性神经元亚型的研究也越来越精细[5]。本文综述了不同亚型的抑制性神经元在杏仁核中的特异性分布及其在焦虑调控中的作用,以期为研究焦虑发生机制和疾病治疗新策略提供参考。
杏仁核在结构上主要分为基底外侧杏仁核(basolateral amygdala, BLA)和中央杏仁核(central amygdala, CeA),分别是主要的输入和输出核团。BLA包括外侧核(lateral amygdala, LA)、基底核(basal amygdala, BA)和基底内侧核(basomedial amygdala, BMA),CeA包括外侧核(lateral central amygdala, CeL)和内侧核(medial central amygdala, CeM)。此外,在BLA外侧以及BLA和 CeA之间存在一些致密的细胞层(intercalated cell masses, ITC)。杏仁核是焦虑调控的关键脑区,但其与焦虑关系的研究报道并不一致。杏仁核增大或缩小[6-7]、激活或抑制[8, 9]都被报道与焦虑障碍存在联系,提示杏仁核参与焦虑调控的机制复杂性。在基础研究中,应用动物实验可以更深入的研究杏仁核在焦虑调控中的作用机制[10]。杏仁核内分布有谷氨酸能兴奋性投射神经元、GABA能抑制性中间神经元和GABA能投射神经元,传统的研究手段很难区分不同类型神经元在焦虑中的作用。基因工程、光遗传学和化学遗传学等实验技术在神经科学领域的应用,为研究不同神经元群体和特定神经投射通路提供了有效的方法。光激活BLA神经元能够减少小鼠在高架十字迷宫开臂中停留的时间,产生致焦虑样作用,但特异性激活BLA神经元投射到CeA的轴突末端却可以增加小鼠在高架十字迷宫开臂中停留的时间,产生抗焦虑样作用[11],提示BLA不同神经元对焦虑行为调控存在差异。因此,明确杏仁核中不同神经元对焦虑的调控作用有助于揭示其调控焦虑的确切机制。
抑制性神经元是一类产生抑制作用的神经元,主要释放抑制性神经递质GABA,占神经元总数的10%~20%。抑制性神经元是大脑抑制性回路的重要组成部分,在保持神经元兴奋与抑制之间的平衡中发挥重要作用。不同的抑制性神经元会特异性表达某种神经肽,如小清蛋白(parvalbumin, PV)、生长抑素(somatostatin, SOM)、缩胆囊素(cholecystokinin, CCK)、血管活性肠肽(vasoactive intestinal peptide, VIP)及蛋白激酶Cδ(protein kinase Cδ, PKCδ)等。表达不同神经肽的抑制性神经元具有分布和功能的特异性,在焦虑调控中也发挥着不同的作用。
杏仁核中,BLA是主要信息接收核团,其中抑制性神经元约占20%,主要包括PV神经元、SOM神经元、CCK神经元和VIP神经元等。这些抑制性神经元通过作用于BLA占比约80%的谷氨酸能兴奋性神经元、BLA下游核团的神经元以及不同类型抑制性神经元之间的相互作用调控杏仁核的信息传递[4-5]。CeA是杏仁核的主要信息输出核团,主要由抑制性神经元构成,包括GABA能投射神经元和中间神经元。CeA的抑制性神经元包括SOM神经元、CCK神经元、PKCδ神经元和促肾上腺皮质激素释放因子(corticotropin releasing factor, CRF)神经元等。应激刺激损伤杏仁核的GABA能神经元,减少GABA释放,导致兴奋/抑制稳态失衡从而诱发焦虑,人为调控这些抑制性神经元的活性也会对实验动物的焦虑样行为产生影响[11]。为了更好地了解杏仁核抑制性神经元与焦虑的关系,人们对不同类型的神经元分别进行了研究,总结见图1。
Figure 1. Regulation of anxiety by the inhibitory neurons in the amygdala. Top left: a diagram showing the amygdala structure and afferent and efferent projections; right: a summary of the effects of neuronal types, intracellular proteins, and projection targets on anxiety. Effects of neuron activation and intracellular proteins on anxiety are shown as anxiogenic (red), anxiolytic (blue), and inconclusive (yellow). BLA: basolateral amygdala; BNST: bed nucleus of the stria terminalis; CeA: central amygdala; ITC: intercalated cell masses; LC: locus coeruleus; PAG: midbrain periaqueductal gray; SLEAc: central sublenticular extended amygdala; CCK: cholecystokinin; CRF: corticotropin releasing factor; PKCδ: protein kinase Cδ; PV: parvalbumin; SOM: somatostatin; ANO2: anoctamin 2; CART: cocaine and amphetamine regulated transcript; CB1R: cannabinoid type 1 receptor; ErbB4: Erb-b2 receptor tyrosine kinase 4; Erbin: ErbB2-interacting protein; GluK1: glutamate ionotropic receptor kainate type subunit 1; NK-1R: neurokinin-1 receptor; NPS: neuropeptide S; NPY2R: neuropeptide Y receptor Y2; OxtR: oxytocin receptor.
2.1.1PV神经元PV神经元是BLA中最主要的抑制性神经元,约占抑制性神经元总数的50%[4]。大部分PV神经元投射到BLA谷氨酸能神经元的胞体和近端树突,少部分投射到远端树突[12],从而对其活性进行调节。母婴分离和甲基氧化偶氮甲醇醋酸盐(methylazoxymethanol acetate)处理会诱导大鼠产生焦虑样行为并伴有BLA PV神经元活性或数量的降低[13, 14];而抗焦虑药和丰富环境能够增加BLA PV神经元的活性和数量从而发挥抗焦虑作用[15, 16]。光遗传学的应用直接证实了BLA PV神经元活性与焦虑的关系,光抑制BLA PV神经元可以增加小鼠在旷场和高架十字迷宫中的焦虑样行为,反之,光激活BLA PV神经元产生抗焦虑样作用[17]。分子机制研究显示,突变或敲低BLA PV神经元中的ErbB2相互作用蛋白(ErbB2-interacting protein, Erbin)会降低PV神经元兴奋性并诱发焦虑样行为,其作用可能是通过减弱PV神经元对BLA椎体神经元的抑制实现的[17]。PV神经元还可以调控其他抑制性中间神经元的活性。Englund等[18]研究显示,BLA PV神经元中具有内源性活性的海人藻酸受体亚基GluK1可以通过激活PV神经元抑制下游SOM中间神经元,从而间接调控谷氨酸能神经元兴奋性,敲除BLA的或母婴分离所致LA中GluK1降低均伴有焦虑样行为的增加。以上研究结果显示,BLA PV神经元可以调控焦虑行为,激活PV神经元具有抗焦虑作用,而抑制其活性具有致焦虑作用。
2.1.2SOM神经元BLA中SOM神经元约占抑制性神经元总数的15%,主要投射到BLA兴奋性神经元的树突棘和远端树突,少量投射到其他抑制性神经元或BLA以外脑区[19]。SOM神经元接收来自VIP和PV神经元的抑制性信号,构成投射神经元前馈调控通路[20]。应激刺激会影响BLA中SOM神经元的活性,Butler等[21]通过SOM与神经元激活标志物c-Fos双标免疫组化实验检测到捕食者气味会降低大鼠BLA中激活状态SOM神经元的数量,而高架十字迷宫暴露则使其数量增加。抑制SOM神经元中GABA的合成可增加小鼠的焦虑样行为[22],相反去抑制SOM神经元活性则具有抗焦虑样作用[23]。以上研究提示SOM神经元参与焦虑行为的调控。激活SOM神经元上神经肽Y(neuropeptide Y, NPY)受体NPY2R可以减少GABA释放从而减弱对投射神经元的抑制作用,使焦虑水平升高[24]。相反,慢性激活BLA的NPY5R会导致投射神经元的兴奋性输入减弱和树突萎缩,并产生抗焦虑样作用[25],但NPY5R是否通过SOM神经元发挥作用尚不清楚。有研究显示其他脑区SOM神经元中代谢型谷氨酸受体5、腺苷酸环化酶3、IQSEC3等功能蛋白参与了SOM神经元活性和焦虑行为的调控[26-28],这些蛋白在BLA的SOM神经元中是否发挥相同的作用尚不清楚。以上研究显示BLA SOM神经元激活具有抗焦虑样作用,抑制具有致焦虑样作用,但目前还缺少光遗传学、化学遗传学实验提供更直接的证据。
2.1.3CCK神经元CCK神经元可以分为胞体较大、共表达钙结合蛋白(calbindin, CALB)的大CCK神经元和胞体较小、共表达钙视网膜蛋白或VIP的小CCK神经元[29]。应用化学遗传学方法激活CCK神经元会增加小鼠在高架十字迷宫闭臂停留的时间,有致焦虑作用[30]。BLA中CCK神经元特异性表达神经激肽1受体(neurokinin-1 receptor, NK-1R),约占BLA中NK-1R阳性细胞的40%,损毁BLA中表达NK-1R的抑制性神经元导致大鼠焦虑样行为增加[31],提示其可能参与CCK神经元对焦虑的调控,但另有约40%的NK-1R表达在NPY阳性的SOM神经元中,因此NK-1R对焦虑的调控是这两类细胞共同作用的结果。与NK-1R不同,1型大麻素受体(cannabinoid type 1 receptor, CB1R)在BLA的大CCK神经元中特异性表达,提示CCK神经元可能参与大麻素对焦虑和应激的调控[32]。CCK神经元具有较高的异质性,其对焦虑的调控可能需要更精细的分类研究。
2.2.1SOM神经元SOM神经元是CeL的主要组成部分,通过与CeA的中间神经元相互作用以及投射到CeA以外核团参与情绪调控[33]。光激活CeA SOM神经元会增加小鼠在旷场、高架十字迷宫和明暗箱实验中的焦虑样行为[34]。光激活CeA SOM神经元会诱导惊恐刺激下小鼠产生被动僵直,而激活CeA CRF神经元则会诱发小鼠的条件性躲避行为,提示SOM神经元和CRF神经元共同作用影响应激反应[35]。CeA SOM投射神经元投射到多个与情绪调控相关的脑区。光激活CeL SOM神经元投射到中央近管状延伸杏仁核(central sublenticular extended amygdala, SLEAc)的轴突末梢可以增加小鼠的焦虑样行为[36]。条件性恐惧刺激能够特异性增强CeA SOM投射神经元的兴奋性突触传递,通过投射抑制中脑导水管周围灰质(midbrain periaqueductal gray, PAG)神经元活性调控恐惧行为[37]。分子机制研究显示,敲除CeL中SOM神经元的Erb-b2受体酪氨酸激酶4(Erb-b2 receptor tyrosine kinase 4, ErbB4)通过增加CeA中SOM神经元活性和去抑制下游终纹床核(bed nucleus of the stria terminalis, BNST)SOM神经元而增加小鼠的焦虑样行为,这一作用与CeL SOM神经元中强啡肽水平升高有关[38]。Li等[39]报道敲除钙激活氯离子通道ANO2的小鼠焦虑样行为减弱,这一作用是通过介导CeA SOM神经元钙激活的氯离子电流以及对其动作电位的影响实现的。以上研究提示,CeA SOM神经元激活具有致焦虑样作用,但其与抗焦虑作用的关系目前报道较少,还需要更进一步研究。
2.2.2PKCδ神经元PKCδ神经元主要分布在CeL,占CeL抑制性神经元的50%,可作用于CeL的其他神经元以及CeM的投射神经元[4, 40]。关于CeA PKCδ神经元活性对焦虑行为影响的报道并不一致。Cai等[41]报道光激活小鼠CeL PKCδ神经元可以在高架十字迷宫、旷场和明暗箱实验中产生抗焦虑样作用;Botta等[42]检测到光激活CeL PKCδ神经元能够增加小鼠在高架十字迷宫和旷场实验中的焦虑行为,而光抑制PKCδ神经元产生抗焦虑样作用;而在Chen等[34]的研究中光激活CeL PKCδ神经元对小鼠在以上三个实验中的焦虑行为没有明显影响。这些研究的光纤植入位置和采用的光刺激条件不同,提示不同位置和不同兴奋性条件下PKCδ神经元对焦虑行为的影响存在差异。PKCδ神经元对焦虑的调控也受到多种信号因子的影响。CeA中65%的PKCδ神经元表达催产素受体(oxytocin receptor, OxtR),研究显示PKCδ神经元介导了催产素抗焦虑和恐惧的作用[40]。可卡因-安非他明调节转录肽(cocaine and amphetamine regulated transcript, CART)也是CeA中PKCδ神经元特异性表达的一种神经肽,育亨宾和乙醇共同作用能够增加小鼠在明暗箱实验中的焦虑样行为,这一作用可以被CeA注射CART抗体所中和,提示CART参与应激诱导焦虑的调控[43]。
2.2.3CRF神经元CRF是应激反应中涉及生理、内分泌、行为反应调控的重要因子,除了参与下丘脑-垂体-肾上腺轴的激活,其在CeA也参与应激和焦虑的调控。CRF神经元大部分集中在CeL,少量在CeM,两个亚区的CRF神经元在电生理和形态学上都存在差异[44]。部分CRF神经元中特异性共表达SOM或PKCδ等神经肽,也证明了其异质性的特点。CeA过表达CRF或光激活CeA中CRF神经元可增加大鼠在旷场和高架十字迷宫中的焦虑样行为[45-46]。CeA CRF神经元投射到多个脑区,光激活或化学遗传学激活其在蓝斑(locus coeruleus, LC)或BNST的末梢可以增加小鼠的焦虑样行为,提示CeA投射到LC和BNST的CRF神经元参与焦虑的调控[47-48]。与激活CRF神经元相反,敲除CeA的CRF或化学遗传学抑制CRF神经元的活性能够减轻应激刺激诱导实验动物的焦虑样行为[48-49]。总体来说,已有研究显示CeA CRF神经元是一类致焦虑神经元,激活诱导焦虑,抑制具有抗焦虑样作用。
2.3杏仁核其他抑制性神经元对焦虑的调控杏仁核中还有一些其他类型的中间神经元也参与恐惧、应激和焦虑的调控。BLA VIP中间神经元主要作用于投射神经元远端树突,部分共表达CB1R、钙视网膜蛋白和/或CCK[4]。研究显示前额叶皮层的VIP神经元参与应激和焦虑的调控[50]。Krabbe等[20]用活体钙成像检测到足底电击刺激能够激活BLA VIP中间神经元,但其是否参与焦虑的调控还有待进一步研究。前面提到位于BLA和CeA之间的ITC主要由抑制性GABA能神经元构成,这些神经元接受来自BLA以及杏仁核外其他脑区的神经投射,并对ITC内部以及BLA和CeA的神经元进行抑制性调控。神经肽S(neuropeptide S, NPS)可通过作用于ITC减轻疼痛诱导的大鼠焦虑样行为[51]。目前对这部分神经元的分类还缺乏系统的研究,Zikopoulos等[52]检测到恒河猴ITC抑制性神经元表达CALB。ITC接收参与情绪调控的谷氨酸能、多巴胺能、去甲肾上腺素能、5-羟色胺能、胆碱能神经投射,这些神经递质系统通过作用于不同受体调控神经元的活性从而发挥情绪调节作用。近年来的研究显示ITC抑制性神经元在恐惧记忆的形成和消退中发挥重要作用,提示其可能是研究焦虑障碍的一个新靶点[53-55]。
杏仁核调控焦虑的机制一直是神经精神科学领域研究的重点和难点。随着光遗传学等技术的应用,出现了大量探究杏仁核内不同种类抑制性神经元在焦虑中作用的研究。相较于在分子和细胞水平的研究,通过对神经元兴奋性及其神经投射通路的调控进行研究能更好地体现神经系统的作用特点。杏仁核中的抑制性神经元种类繁多,相互之间以及与上下游神经投射之间存在复杂的网络连接,不同种类的神经元在焦虑调控中发挥的作用不同,同一种神经元也会由于其所在位置、兴奋性程度差异产生不同的影响。还有一些结构,如ITC,虽然有许多恐惧记忆相关的报道,但其中抑制性神经元的分类以及其对焦虑的调控还需要更多的研究。神经系统的功能,尤其是涉及情绪调节等高级功能的实现需要复杂的网络进行精准的调控以保持其稳态,未来如果能通过形态学、光遗传学等技术的结合绘制出杏仁核调控焦虑的神经网络图谱,不但有利于更好地了解焦虑调控机制,而且对揭示神经系统功能也将具有重大意义。
[1] Baxter AJ, Scott KM, Vos T, et al. Global prevalence of anxiety disorders: a systematic review and meta-regression[J]. Psychol Med, 2013, 43(5):897-910.
[2] Huang Y, Wang Y, Wang H, et al. Prevalence of mental disorders in china: a cross-sectional epidemiological study[J]. Lancet Psychiatry, 2019, 6(3):211-224.
[3] Perumal MB, Sah P. Inhibitory circuits in the basolateral amygdala in aversive learning and memory[J]. Front Neural Circuits, 2021, 15:633235.
[4] Babaev O, Piletti Chatain C, Krueger-Burg D. Inhibition in the amygdala anxiety circuitry[J]. Exp Mol Med, 2018, 50(4):1-16.
[5] Hajos N. Interneuron types and their circuits in the basolateral amygdala[J]. Front Neural Circuits, 2021, 15:687257.
[6] Alemany S, Mas A, Goldberg X, et al. Regional gray matter reductions are associated with genetic liability for anxiety and depression: an MRI twin study[J]. J Affect Disord, 2013, 149(1/2/3):175-181.
[7] Machado-De-Sousa JP, Osorio Fde L, Jackowski AP, et al. Increased amygdalar and hippocampal volumes in young adults with social anxiety[J]. PLoS One, 2014, 9(2):e88523.
[8] Etkin A, Wager TD. Functional neuroimaging of anxiety: a meta-analysis of emotional processing in PTSD, social anxiety disorder, and specific phobia[J]. Am J Psychiatry, 2007, 164(10):1476-1488.
[9] Redlich R, Grotegerd D, Opel N, et al. Are you gonna leave me? Separation anxiety is associated with increased amygdala responsiveness and volume[J]. Soc Cogn Affect Neurosci, 2015, 10(2):278-284.
[10] 刘红霞, 潘虹, 王华, 等. 杏仁核脑区硫化氢对创伤后应激障碍模型大鼠抑郁样行为的影响[J]. 中国病理生理杂志, 2017, 33(6):988-992.
Liu HX, Pan H, Wang H, et al. Effect of amygdala H2S system on depression-like behavior in posttraumatic stress disorder rats[J]. Chin J Pathophysiol, 2017, 33(6):988-992.
[11] Tye KM, Prakash R, Kim SY, et al. Amygdala circuitry mediating reversible and bidirectional control of anxiety[J]. Nature, 2011, 471(7338):358-362.
[12] Vereczki VK, Veres JM, Muller K, et al. Synaptic organization of perisomatic gabaergic inputs onto the principal cells of the mouse basolateral amygdala[J]. Front Neuroanat, 2016, 10:20.
[13] Lukkes JL, Burke AR, Zelin NS, et al. Post-weaning social isolation attenuates c-Fos expression in GABAergic interneurons in the basolateral amygdala of adult female rats[J]. Physiol Behav, 2012, 107(5):719-725.
[14] Yamaguchi T, Minami S, Ueda S. Effects of methylazoxymethanol-induced micrencephaly on parvalbumin-positive gabaergic interneurons in the rat rostral basolateral amygdala[J]. Brain Res, 2021, 1762:147425.
[15] Hale MW, Johnson PL, Westerman AM, et al. Multiple anxiogenic drugs recruit a parvalbumin-containing subpopulation of gabaergic interneurons in the basolateral amygdala[J]. Prog Neuropsychopharmacol Biol Psychiatry, 2010, 34(7):1285-1293.
[16] Urakawa S, Takamoto K, Hori E, et al. Rearing in enriched environment increases parvalbumin-positive small neurons in the amygdala and decreases anxiety-like behavior of male rats[J]. BMC Neurosci, 2013, 14:13.
[17] Luo ZY, Huang L, Lin S, et al. Erbin in amygdala parvalbumin-positive neurons modulates anxiety-like behaviors[J]. Biol Psychiatry, 2020, 87(10):926-936.
[18] Englund J, Haikonen J, Shteinikov V, et al. Downregulation of kainate receptors regulating gabaergic transmission in amygdala after early life stress is associated with anxiety-like behavior in rodents[J]. Transl Psychiatry, 2021, 11(1):538.
[19] Muller JF, Mascagni F, Mcdonald AJ. Postsynaptic targets of somatostatin-containing interneurons in the rat basolateral amygdala[J]. J Comp Neurol, 2007, 500(3):513-529.
[20] Krabbe S, Paradiso E, D'aquin S, et al. Adaptive disinhibitory gating by vip interneurons permits associative learning[J]. Nat Neurosci, 2019, 22(11):1834-1843.
[21] Butler RK, White LC, Frederick-Duus D, et al. Comparison of the activation of somatostatin- and neuropeptide y-containing neuronal populations of the rat amygdala following two different anxiogenic stressors[J]. Exp Neurol, 2012, 238(1):52-63.
[22] Miyata S, Kumagaya R, Kakizaki T, et al. Loss of glutamate decarboxylase 67 in somatostatin-expressing neurons leads to anxiety-like behavior and alteration in the Akt/GSK3β signaling pathway[J]. Front Behav Neurosci, 2019, 13:131.
[23] Fuchs T, Jefferson SJ, Hooper A, et al. Disinhibition of somatostatin-positive gabaergic interneurons results in an anxiolytic and antidepressant-like brain state[J]. Mol Psychiatry, 2017, 22(6):920-930.
[24] Mackay JP, Bompolaki M, Dejoseph MR, et al. Npy2 receptors reduce tonic action potential-independent gabab currents in the basolateral amygdala[J]. J Neurosci, 2019, 39(25):4909-4930.
[25] Michaelson SD, Miranda Tapia AP, Mckinty A, et al. Contribution of NPY Y5receptors to the reversible structural remodeling of basolateral amygdala dendrites in male rats associated with NPY-mediated stress resilience[J]. J Neurosci, 2020, 40(16):3231-3249.
[26] Joffe ME, Maksymetz J, Luschinger JR, et al. Acute restraint stress redirects prefrontal cortex circuit function through mGlu5receptor plasticity on somatostatin-expressing interneurons[J]. Neuron, 2022, 110(6):1068-1083.
[27] Kim S, Park D, Kim J, et al. Npas4 regulates IQSEC3 expression in hippocampal somatostatin interneurons to mediate anxiety-like behavior[J]. Cell Rep, 2021, 36(3):109417.
[28] Yang XY, Ma ZL, Storm DR, et al. Selective ablation of type 3 adenylyl cyclase in somatostatin-positive interneurons produces anxiety- and depression-like behaviors in mice[J]. World J Psychiatry, 2021, 11(2):35-49.
[29] Mascagni F, Mcdonald AJ. Immunohistochemical characterization of cholecystokinin containing neurons in the rat basolateral amygdala[J]. Brain Res, 2003, 976(2):171-184.
[30] Whissell PD, Bang JY, Khan I, et al. Selective activation of cholecystokinin-expressing GABA (CCK-GABA) neurons enhances memory and cognition[J]. eNeuro, 2019, 6(1):ENEURO.0360-18.2019.
[31] Truitt WA, Johnson PL, Dietrich AD, et al. Anxiety-like behavior is modulated by a discrete subpopulation of interneurons in the basolateral amygdala[J]. Neuroscience, 2009, 160(2):284-294.
[32] Mcdonald AJ. Expression of the type 1 cannabinoid receptor (CB1R) in cck-immunoreactive axon terminals in the basolateral amygdala of the rhesus monkey ()[J]. Neurosci Lett, 2021, 745:135503.
[33] Ye J, Veinante P. Cell-type specific parallel circuits in the bed nucleus of the stria terminalis and the central nucleus of the amygdala of the mouse[J]. Brain Struct Funct, 2019, 224(3):1067-1095.
[34] Chen WH, Lien CC, Chen CC. Neuronal basis for pain-like and anxiety-like behaviors in the central nucleus of the amygdala[J]. Pain, 2022, 163(3):e463-e475.
[35] Fadok JP, Krabbe S, Markovic M, et al. A competitive inhibitory circuit for selection of active and passive fear responses[J]. Nature, 2017, 542(7639):96-100.
[36] Sun Y, Qian L, Xu L, et al. Somatostatin neurons in the central amygdala mediate anxiety by disinhibition of the central sublenticular extended amygdala[J/OL]. Mol Psychiatry, 2020 (2020-10-01) [2023-01-08]. https://www.nature.com/articles/s41380-020-00894-1.
[37] Penzo MA, Robert V, Li B. Fear conditioning potentiates synaptic transmission onto long-range projection neurons in the lateral subdivision of central amygdala[J]. J Neurosci, 2014, 34(7):2432-2437.
[38] Ahrens S, Wu MV, Furlan A, et al. A central extended amygdala circuit that modulates anxiety[J]. J Neurosci, 2018, 38(24):5567-5583.
[39] Li KX, He M, Ye W, et al. Tmem16b regulates anxiety-related behavior and gabaergic neuronal signaling in the central lateral amygdala[J]. Elife, 2019, 8:e47106.
[40] Haubensak W, Kunwar PS, Cai H, et al. Genetic dissection of an amygdala microcircuit that gates conditioned fear[J]. Nature, 2010, 468(7321):270-276.
[41] Cai H, Haubensak W, Anthony TE, et al. Central amygdala PKC-δ+neurons mediate the influence of multiple anorexigenic signals[J]. Nat Neurosci, 2014, 17(9):1240-1248.
[42] Botta P, Demmou L, Kasugai Y, et al. Regulating anxiety with extrasynaptic inhibition[J]. Nat Neurosci, 2015, 18(10):1493-1500.
[43] Walker LC, Hand LJ, Letherby B, et al. Cocaine and amphetamine regulated transcript (CART) signalling in the central nucleus of the amygdala modulates stress-induced alcohol seeking[J]. Neuropsychopharmacology, 2021, 46(2):325-333.
[44] Li JN, Chen K, Sheets PL. Topographic organization underlies intrinsic and morphological heterogeneity of central amygdala neurons expressing corticotropin-releasing hormone[J]. J Comp Neurol, 2022, 530(13):2286-2303.
[45] Kalin NH, Fox AS, Kovner R, et al. Overexpressing corticotropin-releasing factor in the primate amygdala increases anxious temperament and alters its neural circuit[J]. Biol Psychiatry, 2016, 80(5):345-355.
[46] Mazzitelli M, Yakhnitsa V, Neugebauer B, et al. Optogenetic manipulations of CeA-CRF neurons modulate pain- and anxiety-like behaviors in neuropathic pain and control rats[J]. Neuropharmacology, 2022, 210:109031.
[47] Mccall JG, Al-Hasani R, Siuda ER, et al. CRH engagement of the locus coeruleus noradrenergic system mediates stress-induced anxiety[J]. Neuron, 2015, 87(3):605-620.
[48] Pomrenze MB, Tovar-Diaz J, Blasio A, et al. A corticotropin releasing factor network in the extended amygdala for anxiety[J]. J Neurosci, 2019, 39(6):1030-1043.
[49] Regev L, Tsoory M, Gil S, et al. Site-specific genetic manipulation of amygdala corticotropin-releasing factor reveals its imperative role in mediating behavioral response to challenge[J]. Biol Psychiatry, 2012, 71(4):317-326.
[50] Johnson C, Kretsge LN, Yen WW, et al. Highly unstable heterogeneous representations in VIP interneurons of the anterior cingulate cortex[J]. Mol Psychiatry, 2022, 27(5):2602-2618.
[51] Ren W, Kiritoshi T, Gregoire S, et al. Neuropeptide S: a novel regulator of pain-related amygdala plasticity and behaviors[J]. J Neurophysiol, 2013, 110(8):1765-1781.
[52] Zikopoulos B, John YJ, Garcia-Cabezas MA, et al. The intercalated nuclear complex of the primate amygdala[J]. Neuroscience, 2016, 330:267-290.
[53] Likhtik E, Popa D, Apergis-Schoute J, et al. Amygdala intercalated neurons are required for expression of fear extinction[J]. Nature, 2008, 454(7204):642-645.
[54] Hagihara KM, Bukalo O, Zeller M, et al. Intercalated amygdala clusters orchestrate a switch in fear state[J]. Nature, 2021, 594(7863):403-407.
[55] Chen M, Li Y, Liu Y, et al. Neuregulin-1-dependent control of amygdala microcircuits is critical for fear extinction[J]. Neuropharmacology, 2021, 201:108842.
Role of amygdala inhibitory neurons in regulating anxiety
ZHOU Han, GUO Ming△
(,,,,256603,)
The amygdala is an important brain region, where inhibitory neurons play key roles in the modulation of anxiety. The major subregions of the amygdala, including the basolateral amygdala (BLA) and the central amygdala (CeA), have different subtypes of inhibitory neurons that are categorized by specific protein expressions. Understanding how these inhibitory neuron subtypes regulate anxiety is important for identifying the neurological basis of anxiety disorders. However, little progress has been made in this regard due to the limitations of experimental techniques. The development and application of genetic engineering and optogenetics in the field of neuroscience enables precise manipulation of the activity and investigation of the function of a locally dense group of neurons expressing the same biomarker. Moreover, they provide effective methods for the functional study of different subtypes of inhibitory neurons in the amygdala. This study presents a literature review on inhibitory neurons in the amygdala in anxiety and, in particular, the neuronal activity and molecular mechanisms that modulate anxiety, to promote a better understanding of the mechanisms underlying anxiety and provide new strategies for the treatment of associated disorders.
amygdala; inhibitory neuron; anxiety; optogenetics
1000-4718(2023)07-1296-06
2023-01-09
2023-07-12
R749.7+2; Q421; R363
A
10.3969/j.issn.1000-4718.2023.07.017
[基金项目]国家自然科学基金资助项目(No. 81771458);山东省重点研发计划项目(No. 2018GSF118181)
0543-3258861; E-mail: byfygm@126.com
(责任编辑:余小慧,罗森)