Nervous System

Abstract

AbstractThe central nervous system of zebrafish includes the spinal cord and brain, and the peripheral nervous system includes the cranial and spinal nerves. The upper part of the spinal cord is connected to the medulla. The spinal cord is parallel to the spine and sends out paired nerves on either side. The gray matter inside the spinal cord is mainly composed of nerve cells. Around the gray matter area, that is the white matter, which is mainly composed of myelinated nerve fibers. Gray matter can be divided into dorsal and ventral horns. The ventral horn contains advanced motor neurons, dendrites, glial cells and Nissl bodies. The spinal cord ends in tapering forming a neurohypophysis at the terminal. The brain includes telencephalon, diencephalon, mesencephalon, cerebellum, medulla oblongata, ventricle and fascicular brain. The telencephalon is located at the front of the central nervous system and includes olfactory bulb and cerebral hemisphere. The olfactory bulb can be divided into epithelial layer, nerve fiber layer, glomerular cell layer and inner cell layer from outside to inside. The sulcus intermedius divides the telencephalic hemisphere into right and left parts, and each telencephalic hemisphere has two main regions: the dorsal part and the ventral part. The diencephalon is located behind the telencephalon, including preoptic area, anterior parietal tectum, superior thalamus, thalamus, hypothalamus and posterior tuberculum. The mesencephalon is located in the dorsal zone of the diencephalon and includes the optic tectum, semicircular torus and tegmentum. The rhombencephalon is the terminal of central nervous system, and include the cerebellum behind the optic lid and the medulla at the end including cerebellum and medulla oblongata. Nerve cells, blood-brain barrier and synapses can be observed in the olfactory bulb, cerebral hemisphere, mesencephalon and cerebellum of zebrafish brain. The ganglion surface is covered by a connective tissue membrane, and the gangliocytes contain Nisi granules. The nerve fibers are divided into myelinated nerve fibers and unmyelinated nerve fibers.