Inhibition of tremulous jaw movements in rats by memantine-Δ9 -tetrahydrocannabinol combination: neuroanatomical correlates.

British Journal of Pharmacology banner“Memantine and marijuana smoking have been previously found to inhibit tremor in parkinsonian patients, however, the observed effects were relatively weak. The tremorolytic efficacy of memantine and cannabinoid co-administration is unstudied.

This work aimed to evaluate antitremor activity of memantine-Δ9 -tetrahydrocannabinol combination; additionally, the involvement of some neuroanatomical structures in the regulation of the combination effect was evaluated.

EXPERIMENTAL APPROACH:

Haloperidol-induced tremulous jaw movements in rats were used as a model of parkinsonian-like tremor. To evaluate the role of central receptor systems in the drug effect, receptor-targeting agents were administered locally into certain brain areas.

KEY RESULTS:

Memantine and Δ9 -tetrahydrocannabinol alone were without effect, however, co-administration of the drugs significantly decreased number of haloperidol-induced jaw movements. The antitremor activity of the combination was antagonized (i) by injections of L-glutamate into the dorsal striatum, entopeduncular nucleus, substantia nigra pars reticulata, globus pallidus, supratrigeminal and trigeminal motor nuclei but not into the subthalamic and cuneiform nuclei; (ii) by injections of CGS 21680 into the ventrolateral striatum; (iii) by injections of bicuculline into the rostral part of the parvicellular reticular nucleus.

CONCLUSION AND IMPLICATIONS:

Memantine and Δ9 -tetrahydrocannabinol supra-additively inhibit haloperidol-induced tremulous jaw movements. Apparently, the co-administration of the drugs might be a new approach to the treatment of tremor. The presented results identify brain areas influencing parkinsonian-like tremor in rats; these data can help advance the development of novel treatments for repetitive involuntary movements.”

https://www.ncbi.nlm.nih.gov/pubmed/31696510

https://bpspubs.onlinelibrary.wiley.com/doi/abs/10.1111/bph.14914

Memantine is a prescription drug used to treat moderate to severe confusion (dementia) related to Alzheimer’s disease. Memantine is available under the following different brand names: Namenda XR, and Namenda.”  https://www.rxlist.com/consumer_memantine_namenda/drugs-condition.htm