During the festival, some people are teetotal, while others drink beer, a glass of wine, or a glass of pure distilled liquor. While body size, gender and the amount of alcohol consumed can influence how intoxicated a person is, individuals also respond differently to alcohol due to differences in genetics and tolerance.1
David Rossi, a molecular neuroscientist at Washington State University, studies the mechanisms that influence drinking.
Washington State University
Alcohol is mainly broken down by two enzymes in the human body, namely alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH). Mutations in these enzymes can alter alcohol metabolism; for example, low ALDH activity can lead to a buildup of metabolites that can lead to flushing and nausea. In addition to metabolism, other factors influence how alcohol affects coordination and drinking behavior.
For example, researchers found that a family history of alcoholism affected symptoms of static ataxia, or body swaying, after drinking: People with a family history swayed less than those without a family history.2 The complexity of this behavior prompted David Rossi, a molecular neuroscientist at Washington State University, to explore the brain because static ataxia involves the cerebellum, a region of the brain involved in motor function and balance.
Alcohol suppresses excitatory signals while enhancing gamma-aminobutyric acid (GABA), the brain’s main inhibitory neurotransmitter. When GABA receptors are stimulated, they reduce neuron firing, causing slowing of movement.3 This destabilizing effect isn’t limited to humans. Rossi found that rodents exhibit similar behavior.
He tested the rodents’ motor skills on a rotarod, comparing rodents with higher antidiuretic hormone (ADH) and aldehyde dehydrogenase (ALDH) activity and a greater thirst for alcohol to those with a lower tolerance. Rodents were compared. He found that the sensitivity of their cerebellar GABA receptors varied.4 He pointed out, ” [rodents] People who really enjoy drinking are very insensitive to the harm alcohol can do to sports. The mice could continue to drink and maintain their balance. Meanwhile, the lighter mice were more likely to feel the intoxicating effects of alcohol and fall.
Tolerance also plays a key role. When mice exit what amounts to a weekend binge, their cerebellums adapt to the inhibitory effects of alcohol. Rossi noted that repeated consumption causes the brain to downregulate inhibitory effects, allowing rodents to maintain function even when pushed beyond their limits.
So whether you’re a light drinker or a seasoned drinker, everyone’s response to alcohol is shaped differently by environmental and genetic influences. Remember, moderation is key!
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