title: Low-intensity electric fields induce two distinct response components in neocortical neuronal populations.
abstract: Low-intensity alternating electric fields applied to the scalp are capable of modulating cortical activity and brain functions, but the underlying mechanisms remain largely unknown. Here, we report two distinct components of voltage-sensitive dye signals induced by low-intensity, alternating electric fields in rodent cortical slices: a "passive component," which corresponds to membrane potential changes directly induced by the electric field; and an "active component," which is a widespread depolarization that is dependent on excitatory synaptic transmission. The passive component is stationary, with amplitude and phase accurately reflecting the cortical cytoarchitecture. In contrast, the active component is initiated from a local "hot spot" of activity and spreads to a large population as a propagating wave with rich local dynamics. The propagation of the active component may play a role in modulating large-scale cortical activity by spreading a low level of excitation from a small initiation point to a vast neuronal population.
authors.affiliation: Department of Neuroscience, Georgetown University Medical Center, Washington, District of Columbia; and.
authors.forename: Weifeng
authors.initials: W
authors.lastname: Xu
authors.affiliation: Department of Neuroscience, Georgetown University Medical Center, Washington, District of Columbia; and Interdisciplinary Program of Neuroscience, Georgetown University Medical Center, Washington, District of Columbia.
authors.forename: Brian S
authors.initials: BS
authors.lastname: Wolff
authors.affiliation: Department of Neuroscience, Georgetown University Medical Center, Washington, District of Columbia; and wuj@georgetown.edu.
authors.forename: Jian-young
authors.initials: JY
authors.lastname: Wu
mesh_terms: D000818:Animals; D004558:Electric Stimulation; D055590:Electromagnetic Phenomena; D008564:Membrane Potentials / Q000502:physiology; D008810:Mice, Inbred C57BL; D019579:Neocortex / Q000166:cytology / Q000502:physiology*; D009474:Neurons / Q000166:cytology / Q000502:physiology*; D046509:Tissue Culture Techniques; D056969:Voltage-Sensitive Dye Imaging
keywords: electric field stimulation; low-intensity field; propagating waves; voltage-sensitive dye imaging