MAPT and tauopathy: Interestingly, recent in vivo studies in tauopathy transgenic mouse models expressing human mutant tau specifically in the entorhinal cortex have shown relocation of tau from axons to the somatodendritic compartment as well as propagation of tau pathology to regions outside the entorhinal cortex, strongly suggesting a trans-synaptic mechanism of spreading of pathology through anatomically connected neuronal networks (de Calignon et al., 2012; Liu et al., 2012).