Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia.
Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia; Deakin University, Centre for Molecular and Medical Research, School of Medicine, Geelong, Australia.
Pharmacol Res. 2021 Aug;170:105729. doi: 10.1016/j.phrs.2021.105729. Epub 2021 Jun 11.
The endocannabinoid system (ECS) comprises two cognate endocannabinoid receptors referred to as CB1R and CB2R ECS dysregulation is apparent in neurodegenerative/neuro-psychiatric disorders including but not limited to schizophrenia, major depressive disorder and potentially bipolar disorder. The aim of this paper is to review mechanisms whereby both receptors may interact with neuro-immune and neuro-oxidative pathways, which play a pathophysiological role in these disorders. CB1R is located in the presynaptic terminals of GABAergic, glutamatergic, cholinergic, noradrenergic and serotonergic neurons where it regulates the retrograde suppression of neurotransmission. CB1R plays a key role in long-term depression, and, to a lesser extent, long-term potentiation, thereby modulating synaptic transmission and mediating learning and memory. Optimal CB1R activity plays an essential neuroprotective role by providing a defense against the development of glutamate-mediated excitotoxicity, which is achieved, at least in part, by impeding AMPA-mediated increase in intracellular calcium overload and oxidative stress. Moreover, CB1R activity enables optimal neuron-glial communication and the function of the neurovascular unit. CB2R receptors are detected in peripheral immune cells and also in central nervous system regions including the striatum, basal ganglia, frontal cortex, hippocampus, amygdala as well as the ventral tegmental area. CB2R upregulation inhibits the presynaptic release of glutamate in several brain regions. CB2R activation also decreases neuroinflammation partly by mediating the transition from a predominantly neurotoxic "M1" microglial phenotype to a more neuroprotective "M2" phenotype. CB1R and CB2R are thus novel drug targets for the treatment of neuro-immune and neuro-oxidative disorders including schizophrenia and affective disorders.
内源性大麻素系统 (ECS) 由两个同源的内源性大麻素受体组成,分别称为 CB1R 和 CB2R。ECS 失调在神经退行性/神经精神障碍中很明显,包括但不限于精神分裂症、重度抑郁症,甚至可能包括双相情感障碍。本文的目的是综述两个受体与神经免疫和神经氧化途径相互作用的机制,这些途径在这些疾病中发挥病理生理作用。CB1R 位于 GABA 能、谷氨酸能、胆碱能、去甲肾上腺素能和 5-羟色胺能神经元的突触前末梢,调节逆行抑制神经传递。CB1R 在长时程抑制和在较小程度上的长时程增强中起关键作用,从而调节突触传递,介导学习和记忆。最佳的 CB1R 活性通过提供对谷氨酸介导的兴奋性毒性发展的防御发挥至关重要的神经保护作用,这至少部分是通过阻碍 AMPA 介导的细胞内钙超载和氧化应激增加来实现的。此外,CB1R 活性使神经元-神经胶质通讯和神经血管单元的功能成为可能。CB2R 受体在周围免疫细胞中以及在包括纹状体、基底神经节、额叶皮质、海马、杏仁核以及腹侧被盖区在内的中枢神经系统区域中被检测到。在几个脑区,CB2R 上调抑制谷氨酸的突触前释放。CB2R 激活还通过介导从主要神经毒性的“M1”小胶质细胞表型向更具神经保护的“M2”表型的转变来部分减少神经炎症。因此,CB1R 和 CB2R 是治疗神经免疫和神经氧化紊乱的新的药物靶点,包括精神分裂症和情感障碍。