Fig. 9

Analysis of hippocampal volume and neuronal numbers in old mice (16 months). a Stereological analysis of the apparent volume of the hippocampus, b number of NeuN positive neurons and c density of the neurons in the CA1, CA3 and DG regions of the hippocampus. The analysis was done on 16 month old animal brains from the control mice, anti-aggregant Tau^RDΔKPP mice, and pro-aggregant Tau^RDΔK mice. a, b There was an increase (~15%) of the hippocampal volume in the old-aged animals from the anti-aggregant Tau^RDΔKPP mice compared to the age-matched controls. This correlates with an increase of neurons (~20%) in the CA3 region, b, bar 5). By contrast, in pro-aggregant old mice the volume decreases 25% relative to controls (a, bar 3); this correlates well with the 10-50% loss of neurons in all regions (b, bars 3, 6, 9). c The density of neurons per mm³ was similar in controls, anti-aggregant and pro-aggregant old mice. Results represent the mean ±SEM (n= 3-5 animals/group)