Search

Recently, we have reported that dentate mossy cells (MCs) control memory precision via directly and functionally innervating local somatostatin (SST) inhibitory interneurons. Here, we report a discovery that dysfunction of synaptic transmission between MCs and SST cells causes memory imprecision in a mouse model of early Alzheimer's disease (AD). Single‐cell RNA sequencing reveals that miR‐128 that binds to a 3′UTR of STIM2 and inhibits STIM2 translation is increasingly expressed in MCs from AD mice. Silencing miR‐128 or disrupting miR‐128 binding to STIM2 evokes STIM2 expression, restores synaptic function, and rescues memory imprecision in AD mice. Comparable findings are achieved by directly engineering MCs with the expression of STIM2. This study unveils a key synaptic and molecular mechanism that dictates how memory maintains or losses its details and warrants a promising target for therapeutic intervention of memory decays in the early stage of AD., Memory is imprecise in an early stage of AD due to a selective degeneration of mossy cell synaptic transmission. MiR‐128 inhibition of STIM2 translation causes a selective degeneration of mossy cell synaptic transmission in an early stage of AD. Uncoupling miR‐128 binding to STIM2 induces STIM2 translation, restores mossy cell synaptic transmission, and rescues memory precision in AD mice.