Cognitive loss in zinc transporter-3 knock-out mice: a phenocopy for the synaptic and memory deficits of Alzheimer's disease?

Zinc transporter-3 (ZnT3) protein controls synaptic vesicular Zn(2+) levels, which is predicted to regulate normal cognitive function. Surprisingly, previous studies found that 6- to 10-week-old ZnT3 knock-out (KO) mice did not show impairment in the Morris water maze. We hypothesized that older ZnT3 KO animals would display a cognitive phenotype.