Total neuron counts in vulnerable and resilient entorhinal subregions

These findings establish a baseline for total neuron number in specific entorhinal subregions of vulnerability (e.g., ECs) and resilience (e.g., ER, EI) at preclinical stage. These data support a previous report that total neuron number in frontal and temporal cortices does not decrease with age (Freeman et al.,2008). Related studies have applied the NvVref method (Gomez-Isla et al. 1996, Gomez-Isla et al. 1997, Freeman et al. 2008), but with varying tau pathology at this stage, optical fractionator is the ideal approach. The total neuron number was consistent with age, however, individual variability in the sample set was evident.