Hippocampal theta rhythm induced by vagal nerve stimulation: The effect of modulation of electrical coupling.
Previously we have demonstrated that vagal nerve stimulation (VNS) is capable of inducing hippocampal formation (HPC) theta rhythm (Broncel et al., 2017). The neuronal substrate underlying this novel phenomenon is poorly known, though the cholinergic and GABAergic profile of VNS-induced theta rhythm in anesthetized rats has just recently been addressed (Broncel et al., 2018a, 2019). In this study we extended our earlier observation concerning the pharmacological profile of VNS-induced theta oscillations. Specifically, the purpose of the present study was to test the hypothesis that VNS-induced hippocampal theta rhythm could be modulated by local HPC gap junctions (GJs) transmission. Two GJs agents were used: carbenoxolone, nonspecific GJs blocker and trimethylamine, a nonspecific opener of GJs. Two basic parameters of theta rhythm were evaluated: frequency and power. It was demonstrated that carbenoxolone inhibits VNS-induced theta while trimethylamine facilities it. These observations indicate that HPC electrical coupling mediates the theta rhythm induced by vagal nerve stimulation.
PMID: 31351158 [PubMed – indexed for MEDLINE]
Brain Res Bull. 2019 10;152:236-245
Authors: Broncel A, Bocian R, Kłos-Wojtczak P, Konopacki J