Acute alcohol exposure impairs neural representation of visual motion speed in the visual cortex area posteromedial lateral suprasylvian cortex of cats

Abstract

Background: Psychophysical and behavioral studies have demonstrated that perception of motion can be impaired by acute alcohol exposure. The neural activities of posteromedial lateral suprasylvian cortex (PMLS) of cats are directly linked to the perception of visual motion speed. To date, there have been no studies on the effects of acute alcohol exposure in vivo upon the representation of speed in PMLS neurons. Methods: Alcohol was administered intravenously as a 20% (v/v) saline solution via a syringe at a dose levels of 0.5, 1, or 2 g/kg to generate a series of blood alcohol concentrations. Using extracellular single-unit recording technique, we recorded the speed-tuning properties of PMLS neurons that responded to random-dot patterns before and after alcohol administration, and simultaneously monitored the concentration of ethanol by detecting the breath alcohol concentration using a breath analyzer. Results: After acute alcohol treatment, PMLS cells preferred lower speeds. A broadened speed-tuning bandwidth of PMLS cells was also observed after acute alcohol administration. Additionally, response modulation and discriminative capacity for speed of visual motion in the PMLS cells were significantly impaired after acute alcohol exposure. Concurrently, PMLS cells after acute alcohol exposure showed decreased spontaneous activity, peak responses, and signal-to-noise ratios. Conclusions: There is a significant functional degradation in the neural representation of visual motion speed in PMLS of cats after acute alcohol exposure. These neural changes may contribute to the alcohol-related deficits in visual motion perception observed in behavioral studies.