Why once you drink you can't think: Alcohol's intoxicating but highly targeted affect on memory and decision making

Alcohol consumption and abuse produces a range of diverse behaviours and responses as a result of neurological ethanol-protein interactions. Acutely intoxicated individuals demonstrate impaired sensory-motor coordination and reduced decision making abilities.

The striatum has already been identified as fundamental to motor and emotional response to ethanol; while the dorsal striatum is also key to reward processing with important implications for further understanding addictive behaviour. Researchers from the University of Manchester made whole-cell electrophysiological recordings using NPI's BA-1s Bridge Amplifer and SEC-10LX, to explore the diverse response of striatal interneurons to ethanol exposure.

Blomeley et al studied different types of striatal interneurons and established their varied but highly specific response to intoxicating concentrations of ethanol. They identified neuronal sub-types based on their characteristic electrophysiological properties and recorded from them using different patch-clamp techniques specific to cell body type and properties. Large aspiny cholinergic interneruons (LAI's) and low threshold spike interneurons (LTSI) were directly inhibited by ethanol. Conversely, fast-spiking interneurons (FSI) were excited by the suppression of potassium currents in the presence of ethanol. Medium spiny neurons (MSN's) were affected indirectly via M1 muscarinic receptors, this was demonstrated by the presence of TTX not affecting the MSN membrane current.

The study published in Neuropsychopharmacology last year offers a comprehensive insight into the heterogeneous nature of striatal interneuron's response to alcohol. They were able to identify that the variable nature of the neurons' response depended on expression of different ionic channels - "different currents [were] modulated by ethanol in each class of stratial interneurons". This provides essential information on the cellular dynamics that will determine future routes for drug therapies in treating sensory-motor disorders, as well as offering significant insight into addictive behaviour.

Ethanol Affects Striatal Interneurons Directly and Projection Neurons Through a Reduction in Cholinergic Tone

Craig P Blomeley, Sarah Cains, Richard Smith and Enrico Bracci

Neuropsychopharmacology (2011) 36, 1033–1046<