SOLUTIONS TO OLD PROBLEMS IN THE QUANTITATION OF THE CENTRAL-NERVOUS-SYSTEM

New stereological techniques, superior to conventional methods in quan titating macroscopic and microscopic structures in the central nervous system, have been developed within the last decade. By the use of a n ew counting method, the dissector, it is possible to obtain an efficie nt and yet precise estimate of the total number of neurons in any spec ific region, where a delineation of the region can be made, and the ce lls identified. The method has been applied to brains from patients wi th different neurological disorders. The latest effort has concentrate d on the estimation of the total neocortical neuron number in brains f rom normal individuals of both sexes in the age from 20 to 90 years to see whether there are differences in total neocortical neuron numbers between males and females.