Low concentration dimethyl sulfoxide (DMSO) modulates epileptiform synchronization in the 4-aminopyridine in vitro
Fei Ran Li1, Mia Gemayel2, Maxime Lévesque3
1Montreal Neurological Institute-Hospital and Departments of Neurology & Neurosurgery and McGill University, 3801 University Street, Montréal, Québec H3A 2B4, Canada; Department of Physiology, McGill University, 3801 University Street, Montréal, Québec H3A 2B4, Canada.
Abstract:
Dimethyl sulfoxide (DMSO) is commonly used to dissolve water-insoluble drugs due to its dipolar and aprotic properties. It also serves as a vehicle in many pharmacological studies. However, it has been reported that DMSO can induce seizures in human patients, lower seizure threshold in vivo, and modulate ion receptors activities in vitro. Therefore, we investigated here the effect of 0.03 % and 0.06 % DMSO, which are 10-50 times lower than what usually employed in previous studies, in the 4-aminopyridine (4AP) model of epileptiform synchronization in male mouse brain slices. We found that 0.03 % and 0.06 % DMSO increase 4AP-induced ictal discharge rate, while 0.06 % DMSO decreases ictal discharge duration. Our results suggest that the effects of DMSO on neuronal excitability deserve further analysis and that investigators need to be aware of its confounding effect as a solvent, even at very low concentrations.
