Acute Alcohol Effects on Neuronal and Attentional Processing: Striatal Reward System and Inhibitory Sensory Interactions under Acute Ethanol Challenge

Abstract

The acute influence of ethanol on cerebral activity induces complex psycho-physiological effects that are considerably more pronounced during acute ethanol influx than during maximal blood alcohol concentration (elimination phase). Despite the psychiatric and forensic relevance of these different ethanol effects, the underlying neuronal mechanisms are still unclear. In total, 20 male healthy volunteers were investigated each with three different experimental conditions in a randomized order using an intravenous ethanol challenge (40 g bolus infusion): during influx phase, elimination phase, and under placebo condition. During and after the ethanol (or placebo) infusion, neuropsychological testing of divided attention for visual and auditory stimuli was performed with subsequent 18-FDG PET acquisition. The PET data were analysed using SPM99. Ethanol influx and elimination phase showed focal activations in the bilateral striatum and frontal cortex and deactivations in the occipital cortex. The comparison of influx phase vs elimination phase revealed activations in the anterior cingulate and right prefrontal cortex, relevant deactivations were found in the left superior temporal cortex including Wernicke's area. Neuropsychological testing showed an attentional impairment under ethanol influx compared to ethanol elimination and placebo with an inverse correlation of the attentional performance for auditory stimuli to occipital activity and for visual stimuli to the left temporal (including auditory) cortex. Acute ethanol administration in healthy volunteers stimulates those striatal regions that are considered to have a particular relevance for alcohol craving ('reward system'). Modality specific reciprocal inhibition of sensory cortex activity seems to be relevant for attentional performance during acute alcohol impact.

Why We Like to Drink: A Functional Magnetic Resonance Imaging Study of the Rewarding and Anxiolytic Effects of Alcohol

“…Activation in the left NAcc and left caudate increased relative to baseline signal in conjunction with subjective ratings of intoxication. These findings confirm PET data indicating increased glucose utilization during alcohol administration in striatum (Wang et al, 2000;Boileau et al, 2003;Schreckenberger et al, 2004), and support Koob's (1992) hypothesis that all drugs of abuse activate the striatum.…”

“…Similarly, functional magnetic resonance imaging (fMRI) studies have shown striatal activation in response to drugs of abuse such as cocaine (Breiter et al, 1997) and nicotine (Stein et al, 1998). Although there have not yet been fMRI studies of the action of alcohol on reward circuits, positron emission tomography (PET) studies demonstrate increased striatal glucose metabolism or blood flow in response to alcohol (Wang et al, 2000;Boileau et al, 2003;Schreckenberger et al, 2004). Accordingly, the mesocorticolimbic reward circuit is important in the development and maintenance of addiction (Koob et al, 1998).…”

Neuropsychological Profile of Acute Alcohol Intoxication during Ascending and Descending Blood Alcohol Concentrations

“…One potentially useful approach to investigate the in vivo effects of acute alcohol intoxication on cognitive performance is neuroimaging. Although many studies have used fMRI and PET imaging techniques to elucidate the neural effects of chronic alcoholism, only a few have addressed the effects of an acute dose of alcohol on cognitive performance (eg Schreckenberger et al, 2004;Vogel-Sprott et al, 2001). These neuroimaging studies have only assessed cognition in a single domain, such as attention or inhibitory control.…”

“…These neuroimaging studies have only assessed cognition in a single domain, such as attention or inhibitory control. Schreckenberger et al (2004) may be the only investigators that aimed to test cognitive performance during rising and declining BACs, but their procedure of using intravenous alcohol resulted in such a rapid rise in BAC that tests could only be administered after peak BACs had occurred. Future neuroimaging research that administers a battery of computerized cognitive tasks, which are linked to a specific brain hemisphere, could explore possible differences between hemispheres in sensitivity to rising and declining BACs.…”

Full number: Volume 11, Number 2 / Número completo: Volumen 11, Número 2

“…En la línea de estos datos, la mayoría de estudios comparativos entre consumidores y no consumidores han encontrado un peor rendimiento en consumidores abusivos en aquellas capacidades relacionadas con la memoria, la atención, las funciones ejecutivas y la fluidez verbal (Carballo, García, Jáuregui, & Sáez, 2009; Gross et al, 2011;Pitel et al, 2008;Schreckenberger et al, 2004). Concretamente, Crego et al (2009) encontraron diferencias electrofisiológicas a nivel cerebral entre consumidores y no consumidores.…”