Dedeurwaerdere S, Wintmolders C, Straetemans R, Pemberton D, Langlois X. Memantine-induced brain activation as a model for the rapid screening of potential novel antipsychotic compounds: exemplified by activity of an mGlu2/3 receptor agonist.
Psychopharmacology (Berl) 2011;
214:505-14. [PMID:
21057775 DOI:
10.1007/s00213-010-2052-z]
[Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2010] [Accepted: 10/12/2010] [Indexed: 02/06/2023]
Abstract
RATIONALE
Schizophrenia is a severe, disabling chronic disorder affecting approximately 1% of the population. Improvements and development of more robust and hopefully predictive screening assays for this disease should enhance the identification and development of novel treatments. The present study describes a rapid and robust method for the testing of potential novel antipsychotics by utilising a simplified [(14)C]2-deoxyglucose (2-DG) autoradiography method following memantine-induced brain activation.
METHODS
Male C57BL/6JCRL mice were given vehicle, ketamine or memantine (10, 20 and 30 mg/kg, subcutaneously (s.c.)) and sacrificed 45 min post-[(14 C)]2-DG administration. In subsequent reversal studies, the memantine challenge was further validated with haloperidol (0.32 mg/kg, s.c.) and clozapine (2.5 and 10 mg/kg, s.c.) in parallel with the ketamine model (Duncan et al. 1998a). Lastly, the effects of an mGlu2/3 receptor agonist, LY404039 (10 mg/kg, s.c.), on both ketamine and memantine-induced brain activation was determined.
RESULTS
Both N-methyl-d-aspartate (NMDA) antagonists dose-dependently induced significant region-specific increases in 2-DG uptake. Interestingly, memantine elicited a considerably greater brain activation signature with a larger dynamic window than ketamine. The "atypical" antipsychotic clozapine significantly reversed memantine-induced 2-DG uptake whilst the "typical" antipsychotic haloperidol was inactive. Pre-treatment with LY404039 fully reversed both the ketamine- and memantine-induced increase in 2-DG uptake without effects on basal 2-DG uptake.
CONCLUSION
This novel pre-clinical imaging methodology displays potential for the screening of compounds targeting the NMDA receptor hypofunction hypothesis of schizophrenia and should assist in developing compounds from the bench to clinic.
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