Increased phosphorylation of Ser473-Akt, Ser9-GSK-3β and Ser133-CREB in the rat frontal cortex after MK-801 intraperitoneal injection

• Published in: The international journal of neuropsychopharmacology Vol. 8; no. 4; pp. 607 - 613
• Main Authors: Ahn, Yong Min, Seo, Myoung Suk, Kim, Se Hyun, Kim, Yeni, Yoon, Se Chang, Juhnn, Yong-Sung, Kim, Yong Sik
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01.12.2005
• Subjects: Brief Report; GSK-3β; MK-801; CREB; Akt
• ISSN: 1461-1457; 1469-5111
• DOI: 10.1017/S1461145705005353

GSK-3β is regarded as playing an important part in the pathogenesis of schizophrenia and the action of psychotomimetic agents. We observed phosphorylation of molecules associated with the GSK-3β signalling pathway in the rat brain after MK-801 injection, which induces a schizophrenia-like state in humans. Ser9-GSK-3β phosphorylation was increased after injection of 1 mg/kg MK-801 in the rat frontal cortex but not in the hippocampus or cerebellum. This increase peaked at 30 min and was maintained until 90 min after injection. The phosphorylation showed a dose-dependent increase up to 1 mg/kg MK-801, followed by a decrease at higher dosage. Furthermore, phosphorylation of Ser473-Akt and Ser133-CREB showed similar temporal, dose-dependent and regionally specific patterns with those of Ser9-GSK-3β. However, phosphorylation of Dvl and Ser33-β-catenin was not affected by MK-801. These results suggest that GSK-3β phosphorylation by MK-801 may be associated with the Akt-GSK-3β pathway rather than with the Wnt-Dvl-GSK3β pathway.