Author: Du X1, Rowland LM2, Summerfelt A2, Choa FS3, Wittenberg GF4,5, Wisner K2, Wijtenburg A2, Chiappelli J2, Kochunov P2, Hong LE2
Affiliation:
1Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, P.O. Box 21247, Baltimore, MD, 21228, USA. xdu@som.umaryland.edu.
2Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, P.O. Box 21247, Baltimore, MD, 21228, USA.
3Department of Electrical Engineering and Computer Science, University of Maryland Baltimore County, Baltimore, MD, 21250, USA.
4Department of Neurology, Physical Therapy and Rehabilitation Science, Internal Medicine, Older Americans Independence Center, University of Maryland, Baltimore, MD, 21201, USA.
5Department of Veterans Affairs (VA) Maryland Health Care System, Geriatrics Research, Education and Clinical Center, and Maryland Exercise & Robotics Center of Excellence, Baltimore, MD, 21201, USA.
Conference/Journal: Cerebellum.
Date published: 2018 May 15
Other:
Special Notes: doi: 10.1007/s12311-018-0945-2. [Epub ahead of print] , Word Count: 236
Cerebellar-prefrontal connectivity has been recognized as important for behaviors ranging from motor coordination to cognition. Many of these behaviors are known to involve excitatory or inhibitory modulations from the prefrontal cortex. We used cerebellar transcranial magnetic stimulation (TMS) with simultaneous electroencephalography (EEG) to probe cerebellar-evoked electrical activity in prefrontal cortical areas and used magnetic resonance spectroscopy (MRS) measures of prefrontal GABA and glutamate levels to determine if they are correlated with those potentials. Cerebellar-evoked bilateral prefrontal synchrony in the theta to gamma frequency range showed patterns that reflect strong GABAergic inhibitory function (r = - 0.66, p = 0.002). Stimulation of prefrontal areas evoked bilateral prefrontal synchrony in the theta to low beta frequency range that reflected, conversely, glutamatergic excitatory function (r = 0.66, p = 0.002) and GABAergic inhibitory function (r = - 0.65, p = 0.002). Cerebellar-evoked prefrontal synchronization had opposite associations with cognition and motor coordination: it was positively associated with working memory performance (r = 0.57, p = 0.008) but negatively associated with coordinated motor function as measured by rapid finger tapping (r = - 0.59, p = 0.006). The results suggest a relationship between regional GABA levels and interregional effects on synchrony. Stronger cerebellar-evoked prefrontal synchrony was associated with better working memory but surprisingly worse motor coordination, which suggests competing effects for motor activity and cognition. The data supports the use of a TMS-EEG-MRS approach to study the neurochemical basis of large-scale oscillations modulated by the cerebellar-prefrontal connectivity.
KEYWORDS: Cerebellar-frontal; Cerebellum; EEG; MRS; Oscillation; TMS
PMID: 29766458 DOI: 10.1007/s12311-018-0945-2
