The neuroprotective effect of lithium chloride on cognitive impairment through glycogen synthase kinase-3β inhibition in intracerebral hemorrhage rats

To the clinical cognitive impairment following intracerebral hemorrhage, comprehensive neuropsychological assessments and efficacious interventions have rarely been conducted. Lithium chloride, a classical treatment for bipolar disorder, has shown neuroprotective effects through glycogen synthase kinase-3β inhibition in a variety of central nervous system diseases, including stroke. Since neurons that contain glutamate play crucial roles in psychological functions, such as learning and memory, the glutamate-mediated excitotoxicity and consequent neuronal death and cognitive impairment in hippocampus may co-determine the clinical course of intracerebral hemorrhage. However, the potential molecular mechanisms have rarely been demonstrated in intracerebral hemorrhage researches. In this study, Male Sprague-Dawley rats, subjected to intrastriatal blood infusion, were treated with lithium chloride and underwent neurobehavioral test for equivalent injury severity and neurological functional deficits, Morris water maze test for cognitive impairment, high performance liquid chromatography analysis for excitotoxic index determination, immunohistochemistry analysis for neuronal apoptosis, and Western blot analysis for glycogen synthase kinase-3β activity. Our results showed lithium chloride inhibited glycogen synthase kinase-3β activation, which on one hand, suppressed downstream CRMP-2/NR2B, thus diminishing the excitotoxic index level; and on the other, stabilized β-catenin, thus modulating its downstream apoptosis-related factors such as NF-κB, Bcl-2 and Bax. Meanwhile, glycogen synthase kinase-3β inactivation was paralleled by decreased neuronal death, improved neurological functional deficits and ameliorated cognitive deficits in intracerebral hemorrhage animals. These findings indicate that lithium chloride improves glutamate-mediated excitotoxicity-induced cognitive deficits after intracerebral hemorrhage and that lithium chloride might be a potential therapeutic agent for brain damages caused by intracerebral hemorrhage.