Among many other side effects, the alcohol affects the cerebellum as well. The mechanism behind this phenomenon is the altering of the neurotransmitters, that are chemical transmitters secreted in the synapses between each neuronal cell. They can either be excitatory or inhibitory. In the case of alcohol, it inhibits the glutamate, that is one of the main excitatory neurotransmitters in the brain and stimulates in the same time the effects the gamma-aminobutyric acid (GABA), that is an inhibitory neurotransmitter responsible for causing sluggish movements and a slurred speech.
As a review, we know already that cerebellum regulates the posture, the coordination and the fine motor control and timing asides the motor learning skill and some cognitive functions (such as the attention or language processing).
Since the ethanol (the chemical substance every alcoholic beverage is based on) stimulates the inhibitory pathways and the GABA A, GABA B and GABA C receptors (the first two are ligand ion channels while the third one is a metabotropic receptor) and suppresses the excitatory pathways and the NMDA receptors, all the functions of the cerebellum are inhibited. In fact, the cerebellum is one of the most sensitive (to alcohol) brain parts.
This is why alcoholics or just casual drinkers experience the following side effects whenever they drink more than they should:
- They lose temporarily the ability of doing fine movements;
They can’t speak properly and have a slurred speech;
Long time alcohol usage can lead to permanent damage (the most often met conditions are hypoplasia or the dysgenesis of the cerebellum, especially if alcohol is abused starting from a young age);
Alcoholics experience confusion, aniscoria and nystagmus, that can be symptoms of the disease called Wernicke Encephalopathy;
They have a poor movement coordination and an impaired vision;
Most of the drinkers have slow reactions;