We have been using memantine hydrochloride from Tocris for behavioral pharmacology and in vivo electrophysiology in rats. In electrophysiology experiments, memantine was delivered with microiontophoresis into the close vicinity of the neurons during recording in the rat cerebral cortex. Memantine was successfully applied from glass micropipettes of multi-barrel electrodes with positive constant currents at acidic pH, and it exerted the expected effect on hippocampal neurons (see attached figure of a representative recording).In behavioral experiments, memantine enhanced cognitive function in scopolamine-induced transient amnesia in rats. However, we found that memantine was effective at substantially lower doses compared to most of the publications from other laboratories.
It is recommended to always perform an initial experiment for the assessment of the dose-response curve, and not to rely on available literature data regarding suggested suitable doses, since the effect of memantine may substantially differ in different assays or behavioral paradigms.