IN THE organism receiving hypnotics the resulting depression of the central nervous system has commonly been divided into three stages, namely, sedation, hypnosis, and general anesthesia. The different stages are customarily ascertained by the signs and symptoms of a subject receiving the depressant. Sedation is recognized primarily as a prehypnotic stage of depression. It is evident that the effective doses, the dose range, and the degree of depression as estimated by such criteria are only approximate values. Therefore, an accurate method is desirable whereby the end-points for the three stages of depression may be easily detected and the depth of depression may be expressed in quantitative terms. The procedure to be described in this paper was designed to meet these requirements.
The method is based on the antagonism between a central-nervous-system depressant and a stimulant. The increase in quantity of the stimulant required to produce convulsions in animals is used
CHEN G, PORTMAN R. TITRATION OF CENTRAL-NERVOUS-SYSTEM DEPRESSION. AMA Arch NeurPsych. 1952;68(4):498–505. doi:10.1001/archneurpsyc.1952.02320220075008