SEX-RELATED ASYMMETRIES IN THE MORPHOLOGY OF THE LEFT AND RIGHT HIPPOCAMPI - A FOLLOW-UP-STUDY ON EPILEPTIC PATIENTS

Cell densities were determined in left and right surgically removed hi ppocampal tissue of epileptic patients. Pyramidal cells were studied i n CA1, CA4, and the dentate gyrus. Lower densities of nucleolated cell s were found for males in the right CA1 and CA4 than on the left while there was no significant left-right difference in females. Moreover, we found a probable sex difference in intercorrelations of nucleolated cells among the three subfields. In males, they were positive and sig nificant on the left while they were low on the right. In females, pos itive significant intercorrelations were obtained between some subfiel ds and not between other subfields, on either side. The present findin gs suggest greater hippocampal lateralization in males than in females with higher hippocampal neuronal connectivity on the left in males th an on the right.