Potassium-ion activity in the trigeminal central nervous complex during tooth pulp-evoked slow mass potentials

Abstract Following electrical stimulation of the tooth pulp, extracellular K + activity was enhanced by up to 0.1 mM only in the trigeminal motor nucleus which gave a positive slow mass potential (SMP) of low amplitude. No nuclear region giving a positive or negative SMP of high amplitude showed any detectable change. There are possible generation mechanisms of the negative and positive SMP.