Ma, JeannineShaw, Victoria EMitrofanis, John2015-12-101353-8020http://hdl.handle.net/1885/52466This study explores whether melatonin neuroprotects dopaminergic cells of the substantia nigra pars compacta (SNc) from degeneration in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice (well-known animal model of Parkinson disease). BALB/c albino mice were divided into four experimental groups. In each, mice received three series (over a 24-h period) of two intraperitoneal injections (1 h apart) in different combinations. The different groups and their combinations of injections were: (1) Saline (saline, saline); (2) Mel (melatonin, saline); (3) MPTP (saline, MPTP); (4) Mel-MPTP (melatonin, MPTP). Six days after the last injection, all mice were perfused transcardially with aldehyde fixative. Brains were processed for routine tyrosine hydroxylase (TH; rate limiting enzyme for dopamine production) immunochemistry and Nissl staining. Our results - using unbiased stereology - showed that there were more TH+ (50%) and Nissl-stained (30%) cells in the SNc of the Mel-MPTP group compared to the MPTP group, indicating a clear saving or neuroprotection of these cells. In fact, we found no significant difference between the number of TH+ and Nissl-stained SNc cells in the Mel-MPTP group compared to the controls, namely Saline and Mel groups. This indicated that melatonin pre-treatment potentially neuroprotected all the SNc cells from MPTP toxicity and death. CrownKeywords: 1,2,3,6 tetrahydro 1 methyl 4 phenylpyridine; aldehyde; melatonin; sodium chloride; tyrosine 3 monooxygenase; animal experiment; animal model; animal tissue; article; Bagg albino mouse; controlled study; dopaminergic nerve cell; immunochemistry; male; mou Basal ganglia; Cell death; Neuroprotection; Parkinson disease200910.1016/j.parkreldis.2008.07.0082016-02-24