Thus, Shetty and Turner (1999) found a decreased number
of hilar neurons in male 22-month-old Fischer 344
rats. In addition, Azcoitia et al. (2005) reported a
significant neuronal loss in the dentate hilus of male
Wistar rats aged between 22- and 24-month-old, compared
with 18-month-old counterparts. This discrepancy
could be accounted for by differences in the hippocampal
region studied, as we counted in the whole hippocampus,
not just in the hilus.