CASP6 and Mental deterioration: Given that the presence of active Casp6 detected in the entorhinal cortex of aged individuals correlates with decreased cognitive performance1,7,12,42 and that early cognitive decline is strongly correlated with synaptic loss56,57, these data raise the possibility that the active Casp6 observed in neuropil threads, neuritic plaques and neurofibrillary tangles4,5 causes synaptic transmission problems.