Neuronal and lymphocytic populations in human trigeminal ganglia: implications for ageing and for latent virus.

The number of neurones and of lymphocytes was determined morphometrically in serial sections of trigeminal ganglia harvested at autopsy from 64 human subjects dying at ages 2 months to 81 years. The nerve cell population varied from 20 159 to 156 702 with a mean of 80 638 /ganglion and was unaffected by increasing age. The degree of lymphocytic infiltration, which was prominent and ubiquitous, also did not correlate with the subjects' age. There was no significant correlation between neuronal and lymphocyte counts. The inflammatory cells present throughout life apparently are unassociated with any detrimental effect upon the sensory neurones, and may represent a histopathological marker either of reactivating herpes virus or of virus maintained in a latent state within the Gasserian ganglia of man.