Assignment Title: Effects of Ethanol on the GABAA Receptor.
Ethanol is a form of alcohol and is a substance that has many profound effects on the human body when consumed. Recent evidence shows a connection between ligand gated ion channels, neurotransmitters and an inhibitory effect on the central nervous system (CNS) when ethanol is present(Davies). Specifically, the effect of alcohol on the neurotransmitter gamma-aminobutyric acid (GABA). When GABA binds to the GABAA receptor with ethanol the result on the central nervous system is intoxication and multiple behavioural changes (Lobo).
The GABAA receptor is nested in the cell membrane of neurons (post synaptic cell) and is classified as a ligand gated ion channel. These channels open in response to a neurotransmitter (GABA), allowing ions (e.g. chloride ions) to flow from the exterior to interior of the cell, increasing the cells polarization which prevents the spread of an action potential or signal to pass between neurons. The GABAA receptor is composed of five subunits (two Alpha, one Beta, and two Gamma subunits) which are arranged so that a channel is formed at the centre of the complex. A large portion of the GABAA receptor's mass is located in the extracellular region while a smaller portion spans the cell membrane, coming into contact with intracellular region of the cell. The main function of the extracellular region is the binding of ligands, while the intracellular region of the protein can be modified through phosphorilation, affecting the overall function and performance of GABAA receptor (everything up to this pt in paragraph by Mihic). These ligand gated ion channels play a key role in the rapid neuronal transmission of the CNS and are distributed throughout the brain (Lobo). The interactions of the ligand gated ion channels (GABAA receptors) are a crucial element and changes in their interactions through the introduction of ethanol can attribute to the wide variety of behavioural and cognitive effects that occur while intoxicated.
