Over activation of hippocampal serine/threonine protein phosphatases PP1 and PP2A is involved in lead-induced deficits in learning and memory in young rats

► Pb-induced cognitive deficits involves over activation of hippocampal PP1 and PP2A. ► PP1 overactivation appears to affect learning and LTM; PP2A appears to affect STM. ► Decreased synaptogenesis is associated with impaired learning and LTM but not STM. ► Pb-induced increase in PP1 activity appears to dephosphorylate tau at T231. ► Pb-induced phosphorylation of S199/S202 appears to depend on PP2A activity.