Anticonvulsants attenuate amyloid β-peptide neurotoxicity, Ca2+ deregulation, and cytoskeletal pathology

Increasing evidence supports the involvement of amyloid β-peptide (Aβ) and an excitotoxic mechanism of neuronal injury in the pathogenesis of Alzheimerʹs disease. However, approaches aimed at preventing Aβ toxicity and neurofibrillary degeneration are undeveloped. We now report that anticonvulsants (carbamazepine, phenytoin, and valproic acid) can protect cultured rat hippocampal neurons againsts Aβ- and glutamate-induced injury. Each of the anticonvulsant attentuated the elevated of intracellular free calcium levels [(Ca2+)i] elicited by Aβ or glutamate suggesting that their neuroprotective mechanism of action involved stabilization of [Ca2+]i. These compounds were effective at clinically relevant concentrations (carbamazepine, 100 nM-10 μM; phenytoin, 100 nM-1 μM; valproic acid, 100 nM-100 μM). The anticonvulsants suppressed glutamate-induced alterations in tau and ubiquitin immunoreactivities. Compounds that stabilize [Ca2+]i may afford protection against the kinds of insults believed to underlie neuronal injury in Alzheimerʹs disease.