Disruptions in functional network connectivity during alcohol intoxicated driving.
BACKGROUND
Driving while under the influence of alcohol is a major public health problem whose neural basis is not well understood. In a recently published functional magnetic resonance imaging (fMRI) study (Meda et al., 2009), our group identified 5, independent critical driving-associated brain circuits whose inter-regional connectivity was disrupted by alcohol intoxication. However, the functional connectivity between these circuits has not yet been explored in order to determine how these networks communicate with each other during sober and alcohol-intoxicated states.


METHODS
In the current study, we explored such differences in connections between the above brain circuits and driving behavior, under the influence of alcohol versus placebo. Forty social drinkers who drove regularly underwent fMRI scans during virtual reality driving simulations following 2 alcohol doses, placebo and an individualized dose producing blood alcohol concentrations (BACs) of 0.10%.


RESULTS
At the active dose, we found specific disruptions of functional network connectivity between the frontal-temporal-basal ganglia and the cerebellar circuits. The temporal connectivity between these 2 circuits was found to be less correlated (p < 0.05) when driving under the influence of alcohol. This disconnection was also associated with an abnormal driving behavior (unstable motor vehicle steering).


CONCLUSIONS
Connections between frontal-temporal-basal ganglia and cerebellum have recently been explored; these may be responsible in part for maintaining normal motor behavior by integrating their overlapping motor control functions. These connections appear to be disrupted by alcohol intoxication, in turn associated with an explicit type of impaired driving behavior.
Rzepecki-Smith
Catherine I
CI
Olin Neuropsychiatry Research Center, Institute of Living/Hartford Hospital, Hartford, Connecticut, USA. crzepecki@harthosp.org
Meda
Shashwath A
SA
Calhoun
Vince D
VD
Stevens
Michael C
MC
Jafri
Madiha J
MJ
Astur
Robert S
RS
Pearlson
Godfrey D
GD
D000328:Adult; D000435:Alcoholic Intoxication / Q000503:physiopathology*; D001334:Automobile Driving; D001921:Brain / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009415:Nerve Net / Q000503:physiopathology*; D055815:Young Adult