Memantine modulates neuroinflammation and motor coordination in a Parkinson's disease model.

Memantine, an NMDA receptor antagonist clinically approved for Alzheimer's disease, has been implicated in modulating neuroinflammatory responses beyond its anti-excitotoxic actions. To explore its potential relevance in Parkinson's disease, this study evaluated memantine's effects in both LPS-activated microglial cells and a synucleinopathy mouse model. In BV-2 cells, memantine elicited a modest but measurable attenuation of TNF-α and IL-6 secretion, which was accompanied by downregulation of TLR4 and IκB signaling. In vivo, 5-month oral administration of memantine to mThy1-αSyn transgenic mice led to moderate improvements in motor function as assessed by beam-walk performance. Immunohistochemical analyses revealed decreased microglial activation in the cerebral cortex; however, phosphorylated α-synuclein accumulation and tyrosine hydroxylase expression remained unaffected. Furthermore, spatial working memory was not improved by treatment. Taken together, these findings suggest that memantine may exert beneficial effects on neuroinflammatory processes and behavioral deficits in PD-relevant models. However, its impact on the hallmark neuropathology of PD appears limited.