Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, United States; Helen Wills Neuroscience Institute, University of California, Berkeley, CA, United States.
Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, United States; Helen Wills Neuroscience Institute, University of California, Berkeley, CA, United States.
Curr Opin Pharmacol. 2022 Apr;63:102198. doi: 10.1016/j.coph.2022.102198. Epub 2022 Mar 8.
To better understand neural circuits and behavior, microbial opsins have been developed as optogenetic tools for stimulating or inhibiting action potentials with high temporal and spatial precision. However, if we seek a more reductionist understanding of how neuronal circuits operate, we also need high-resolution tools for perturbing the function of synapses. By combining photochemical tools and molecular biology, a wide variety of light-regulated neurotransmitter receptors have been developed, enabling photo-control of excitatory, inhibitory, and modulatory synaptic transmission. Here we focus on photo-control of GABA receptors, ligand-gated Cl channels that underlie almost all synaptic inhibition in the mammalian brain. By conjugating a photoswitchable tethered ligand onto a genetically-modified subunit of the GABA receptor, light-sensitivity can be conferred onto specific isoforms of the receptor. Through gene editing, this attachment site can be knocked into the genome, enabling photocontrol of endogenous GABA receptors. This strategy can be employed to explore the cell biology and neurophysiology of GABA receptors. This includes investigating how specific isoforms contribute to synaptic and tonic inhibition and understanding the roles they play in brain development, long-term synaptic plasticity, and learning and memory.
为了更好地理解神经回路和行为，微生物视蛋白已被开发为光遗传学工具，可实现具有高时间和空间精度的刺激或抑制动作电位。然而，如果我们寻求对神经元回路如何运作的更简化的理解，我们还需要用于干扰突触功能的高分辨率工具。通过结合光化学工具和分子生物学，已经开发出了各种各样的光调节神经递质受体，从而能够对兴奋性、抑制性和调制性突触传递进行光控。在这里，我们重点介绍 GABA 受体的光控，GABA 受体是配体门控的 Cl-通道，构成了哺乳动物大脑中几乎所有的突触抑制。通过将光可切换的连接配体连接到 GABA 受体的基因修饰亚基上，可以赋予受体特定亚型光敏感性。通过基因编辑，该附着位点可以敲入基因组，从而实现对内源性 GABA 受体的光控。这种策略可用于探索 GABA 受体的细胞生物学和神经生理学。这包括研究特定亚型如何有助于突触和紧张性抑制，并了解它们在大脑发育、长期突触可塑性以及学习和记忆中的作用。
