TY - JOUR
T1 - Entrainment of cerebellar purkinje cells with directional AC electric fields in anesthetized rats
AU - Asan, Ahmet S.
AU - Lang, Eric J.
AU - Sahin, Mesut
N1 - Funding Information:
This work was supported by the National Institutes of Health [ R21 NS101386 ].
Publisher Copyright:
© 2020 The Author(s)
PY - 2020/11/1
Y1 - 2020/11/1
N2 - Background: Transcranial electrical stimulation (tES) shows promise to treat neurological disorders. Knowledge of how the orthogonal components of the electric field (E-field) alter neuronal activity is required for strategic placement of transcranial electrodes. Yet, essentially no information exists on this relationship for mammalian cerebellum in vivo, despite the cerebellum being a target for clinical tES studies. Objective: To characterize how cerebellar Purkinje cell (PC) activity varies with the intensity, frequency, and direction of applied AC and DC E-fields. Methods: Extracellular recordings were obtained from vermis lobule 7 PCs in anesthetized rats. AC (2–100 Hz) or DC E-fields were generated in a range of intensities (0.75–30 mV/mm) in three orthogonal directions. Field-evoked PC simple spike activity was characterized in terms of firing rate modulation and phase-locking as a function of these parameters. t-tests were used for statistical comparisons. Results: The effect of applied E-fields was direction and intensity dependent, with rostrocaudally directed fields causing stronger modulations than dorsoventral fields and mediolaterally directed ones causing little to no effect, on average. The directionality dependent modulation suggests that PC is the primary cell type affected the most by electric stimulation, and this effect was probably given rise by a large dendritic tree and a soma. AC stimulation entrained activity in a frequency dependent manner, with stronger phase-locking to the stimulus cycle at higher frequencies. DC fields produced a modulation consisting of strong transients at current onset and offset with an intervening plateau. Conclusion: (s): Orientation of the exogenous E-field critically determines the modulation depth of cerebellar cortical output. With properly oriented fields, PC simple spike activity can strongly be entrained by AC fields, overriding the spontaneous firing pattern.
AB - Background: Transcranial electrical stimulation (tES) shows promise to treat neurological disorders. Knowledge of how the orthogonal components of the electric field (E-field) alter neuronal activity is required for strategic placement of transcranial electrodes. Yet, essentially no information exists on this relationship for mammalian cerebellum in vivo, despite the cerebellum being a target for clinical tES studies. Objective: To characterize how cerebellar Purkinje cell (PC) activity varies with the intensity, frequency, and direction of applied AC and DC E-fields. Methods: Extracellular recordings were obtained from vermis lobule 7 PCs in anesthetized rats. AC (2–100 Hz) or DC E-fields were generated in a range of intensities (0.75–30 mV/mm) in three orthogonal directions. Field-evoked PC simple spike activity was characterized in terms of firing rate modulation and phase-locking as a function of these parameters. t-tests were used for statistical comparisons. Results: The effect of applied E-fields was direction and intensity dependent, with rostrocaudally directed fields causing stronger modulations than dorsoventral fields and mediolaterally directed ones causing little to no effect, on average. The directionality dependent modulation suggests that PC is the primary cell type affected the most by electric stimulation, and this effect was probably given rise by a large dendritic tree and a soma. AC stimulation entrained activity in a frequency dependent manner, with stronger phase-locking to the stimulus cycle at higher frequencies. DC fields produced a modulation consisting of strong transients at current onset and offset with an intervening plateau. Conclusion: (s): Orientation of the exogenous E-field critically determines the modulation depth of cerebellar cortical output. With properly oriented fields, PC simple spike activity can strongly be entrained by AC fields, overriding the spontaneous firing pattern.
KW - Cerebellar modulation
KW - Electrical stimulation
KW - Spike entrainment
KW - Transcranial alternating current stimulation (tACS)
KW - Transcranial direct current stimulation (tDCS)
UR - http://www.scopus.com/inward/record.url?scp=85091218754&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85091218754&partnerID=8YFLogxK
U2 - 10.1016/j.brs.2020.08.017
DO - 10.1016/j.brs.2020.08.017
M3 - Article
C2 - 32919090
AN - SCOPUS:85091218754
SN - 1935-861X
VL - 13
SP - 1548
EP - 1558
JO - Brain Stimulation
JF - Brain Stimulation
IS - 6
ER -