Abstract
The cerebral cortex exhibits regional variation in cytoarchitectonics and cellular morphology. Previous research has suggested qualitative regional variations in pyramidal and nonpyramidal cells (Ramón y Cajal, 1911) and quantitative regional differences in the basilar dendrites of pyramidal cells (Jacobs et al., 1997). The present study quantitatively compares dendritic extent of spine-free nonpyramidal cells in Brodmann's area (BA) 10 and BA18 of the human cerebral cortex. Tissue was obtained from the left hemisphere of ten neurologically normal adults ranging in age from 23 to 73 years (Mean=44±18). After processing with a modified rapid Golgi technique (Scheibel & Scheibel, 1978) two neurons per brain region (N=40) were quantified on a Neurolucida computer/microscope interface system (Microbrightfield, Inc.). Cells were evaluated for total dendritic length, mean segment length, and dendritic segment count. Little regional variation in dendritic extent was found, suggesting that unlike pyramidal cells, which synthesize information from several cortical and sub-cortical structures, aspiny non-pyramidal neurons appear to be limited to local neocortical integration. Moreover, overall dendritic extent was substantially less in non-pyramidal cells than in pyramidal cell basilar dendrites, especially in BA10. (Tissue generously provided by Dr. D. Bowerman of the El Paso County coroner's office, Dr. R. Sherwin of Penrose Hospital in Colorado Springs, Colorado, and Drs. E. Orsini and W. Tyson of Denver's Children's Hospital).