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Methamphetamine (METH) abuse is known to cause executive dysfunction. However, the molecular mechanism underlying METH induced executive dysfunction remains unclear. Go/NoGo experiment was performed in mice to evaluate METH-induced executive dysfunction. Immunoblot analysis of Nuclear factor-E2-related factor 2 (Nrf2), phosphorylated Nrf2 (p-Nrf2), heme-oxygenase-1 (HO-1), Glucose Regulated Protein 78(GRP78), C/EBP homologous protein (CHOP), Bcl-2, Bax and Caspase3 was performed to evaluate the levels of oxidative stress, endoplasmic reticulum (ER) stress and apoptosis in the dorsal striatum (Dstr). Malondialdehyde (MDA) levels and glutathione peroxidase (GSH-Px) activity was conducted to evaluate the level of oxidative stress. TUNEL staining was conducted to detect apoptotic neurons. The animal Go/NoGo testing confirmed that METH abuse impaired the inhibitory control ability of executive function. Meanwhile, METH down-regulated the expression of p-Nrf2, HO-1 and GSH-Px and activated ER stress and apoptosis in the Dstr. Microinjection of Tert-butylhydroxyquinone (TBHQ), an Nrf2 agonist, into the Dstr increased the expression of p-Nrf2, HO-1, and GSH-Px, ameliorated ER stress, apoptosis and executive dysfunction caused by METH. Our results indicated that the p-Nrf2/HO-1 pathway was potentially involved in mediating methamphetamine-induced executive dysfunction by inducing endoplasmic reticulum stress and apoptosis in the dorsal striatum. [ABSTRACT FROM AUTHOR]

Repeated exposure to methamphetamine (METH) can cause severe neurotoxicity to the cortical neurons. In the present study, we investigated the effect of METH on cognitive function deficits, and determined the neuroprotective effects of memantine (MEM) on memory impairment induced by METH. The protein levels of Bcl-2 and cleaved caspase-3 in prefrontal cortex (PFC) were further examined to exploring the underlying mechanism. We found that repeated METH administration impaired long term (24 h) memory retention without affecting short term (5 min) memory retention. Co-administration of MEM with METH before training session significantly improved METH-induced cognitive function. METH significantly decreased expression level of Bcl-2 and increased expression level of cleaved caspase-3 in the PFC. The changes can be prevented by MEM pretreatment. Thus, these results demonstrated that MEM pretreatment reversed METH-induced changes of protein levels of apoptotic-related gene, and produced protective effects against METH-induced cognitive deficits, suggesting the effectiveness of MEM may be due to its anti-apoptotic activity. [ABSTRACT FROM AUTHOR]