Optogenetic investigation of neuropsychiatric diseases

Optogenetic technology, also known as optogenetics, is a novel multidisciplinary field in biotechnology that integrates genetic engineering, electrophysiology, and optical and electronic engineering. This recently developed technology has evolved rapidly and generated considerable excitement in neuroscience research. This technology successfully solves the severe problem of achieving both high temporal and spatial precision within intact neural tissues of animals that electrical stimulation and pharmacological methods cannot achieve. It allows neurons to express light-sensitive genes that enable the identification, dissection, and manipulation of specific neural populations and their connections in the tissues and organs of awake animals with unprecedented spatial and temporal precision. Light-sensitive genes chiefly including the genetically targeted light-gated channels channelrhodopsin-2 (ChR2) and halorhodopsin (NpHR) cause intracellular ion flow during optical illumination. Subsequently, the neurons undergo a series of changes resulting from membrane depolarization or hyperpolarization. To date, there are many published research articles and reviews that describe this new technology; however, few of the reports concern its application to neuropsychiatric diseases. In this review, we summarize the most recent optogenetic research in these diseases, including Parkinson's disease (PD), epilepsy, schizophrenia, anxiety, fear, reward behaviors, and sleep disorders. We propose that novel optogenetics technology creates excellent opportunities for innovative treatment strategies of neuropsychiatric diseases.