Transcranial ac modulation of cerebellar nuclear activity in awake animals

Author

• Nuran Kavakli, New Jersey Institute of TechnologyFollow

Author ORCID Identifier

0009-0002-0880-3185

Document Type

Dissertation

Date of Award

5-31-2026

Degree Name

Doctor of Philosophy in Biomedical Engineering - (Ph.D.)

Department

Biomedical Engineering

First Advisor

Mesut Sahin

Second Advisor

Bharat Biswal

Third Advisor

Sergei Adamovich

Fourth Advisor

Eric J. Lang

Fifth Advisor

Soha Saleh

Sixth Advisor

Ozlem Gunal

Abstract

Entrainment of cerebellar nuclear (CN) cells via cerebellar transcranial alternating current stimulation (ctACS) has been reported in animals under ketamine/xylazine anesthesia. Our main objective was to demonstrate modulation of CN activity in unanesthetized, freely moving animals using ctACS. Multi-channel carbon-fiber electrodes were implanted into the interpositus nucleus for recording multi-unit (MU) activity, and thin-film electrodes were implanted subcutaneously over the posterior cerebellum for stimulation. A frequency-domain-based metric was developed to quantify modulation from MU signals. The results demonstrated modulation in a wide range of frequencies (4 Hz-300 Hz) as in anesthetized animals. In contrast, the amplitude of the peak in mid-frequencies was much less prominent and shifted toward lower frequencies (30 Hz-50 Hz). Signal power in gamma bands was slightly increased, and the power in theta and alpha bands was slightly decreased by tACS applied at higher frequencies than the LFP band of interest, in a direction opposite to the effects induced by isoflurane anesthesia. Amplitude modulated (AM) stimulation was also able to induce modulation of the MU activity in the CN at the frequency of the AM envelope in a frequency dependent manner. Detection of modulation from MU activity is intrinsically noisy. Nonetheless, the results confirm modulation of the CN cells through stimulation of the cerebellar cortex using transcranial stimulation in awake animals. The way ctACS may affect the animal's behavior needs to be investigated in future studies. Overall, these findings establish that ctACS can effectively modulate cerebellar nuclear activity in awake, freely moving animals across a broad frequency

Recommended Citation

Kavakli, Nuran, "Transcranial ac modulation of cerebellar nuclear activity in awake animals" (2026). Dissertations. 1881.
https://digitalcommons.njit.edu/dissertations/1881