The construction of oscillotome and electrophysiological study of rat cerebellar slices

Abstract

Recently, an in vitro study of the mammalian CNS using thin (100-500 um) sectioned tissue, so-called brain slice preparation, has become popular among neurobiologists as a useful tool for neurophysiology and neuropharmcology. This study, therefore, aims to develop cerebellar slice preparation by utilizing materials available locally, some from discarded instruments. The development consists mainly of three basic elements. First, an automatic tissue sectioner, so-called Oscillotome, had been constructed. The machine produces thin train slices by cutting in the horizontal plane under 2℃ ACSF (artificial cerebrospinal fluid). In addition, the hand-slicing technique was also developed for comparative study to the machine method. Second, an superfusion tissue chamber had been constructed. The bath keeps the slices fully submerged in the perfused media. Third, a superfusion system had been designed. Rapid changing of the medium would facilitate pharmacological study when rapid termination of the action of the drug under study was required. Validation of these elements had been performed by producing 300 um rat cerebellar slices. The slices obtained by this method showed the better morphology than those obtained by hand-slicing method. Extracellular recording of neuronal activity obtained various patterns of discharge. Under the suitable condition of ACSF (30℃-37℃) cells could be maintained over a period of 6 and 10 hours. Most activities were depressed during exposure to cold ACSF (20℃) but increased by glutamate.