Deciphering cerebellar neural circuitry involved in higher order functions using the zebrafish model

Abstract

The central nervous system (CNS) in vertebrate species is one of the most complex structures in the animal body, containing enormous numbers of neurons that connect to each other through their axons and dendrites to carry out complex tasks. Recent comparative anatomical and functional studies of neural circuits in different vertebrate CNS reveal that, although the structure of the CNS is simpler in lower vertebrates (such as teleosts) than that in mammals, the basic organization of neural circuitry in the CNS is conserved and the formation of neural circuits is controlled by similar or identical mechanisms. In this chapter, we focus on the cerebellum, which is derived from the dorsal part of the most anterior hindbrain and is involved in motor control and higher cognitive/emotional functions. We describe the structure and development processes of the cerebellar neurons and neural circuits in zebrafish and compared them with those in mammals. A variety of techniques and resources is available for zebrafish research on neural development and function, including classical reverse genetics, transgenics, and optogenetics. We discuss how studies on neural circuitry in zebrafish provide us with a general scheme of the formation and function of cerebellar neural circuitry in vertebrate species.