They are chemical signals generated only by a few small clusters of cells deep in the middle of the brain, but broadcast widely across the brain. One such neuromodulator is called dopamine. To understand alcohol, both the impact on GABA and on dopamine is important. GABA is the main inhibitory neurotransmitter in the brain. Because lots of neurons talk to each other and excite each other, the brain is in a bit of a dangerous place. All the positive feedback can generate explosive activity resulting in epilepsy.
To avoid this, there has to be inhibition in the system, and GABA is the key player in this. Alcohol stimulates GABA receptors, and thereby dampens activity in the brain. It is thought that this is why it produces an immediate reduction of anxiety, and overdoses can lead to coma. If there is a constant supply of alcohol, however, the brain receptors adapt by reducing GABA receptors.
All is good as long as there is alcohol in the system driving the few remaining GABA receptors hard. But if a regular drinker stops very suddenly, say from one day to the other, then suddenly there is insufficient inhibition in the system and epileptic fits can result. This is why a heavy drinker should never stop drinking without medical support. It's dangerous. Less severe versions of this result in the morning withdrawal symptoms well-known to heavy drinkers - anxiety, sweating, tremor, nervousness, agitation, anger, dysphoria.
In fact, this is the new "normal" when drinking heavily - the GABA adaptation puts the brain into a constant state of anxiety, irritation and agitation. To understand why we continue drinking despite these negative effects, we have to turn to two other aspects of alcohol. First, like other drugs, it mischievously seems to sort out the mess it creates: The first morning dose of alcohol appears as a helpful friend - miraculously resolving all tremors, anxiety and nausea it caused itself in the first place, subtly sending the signal that alcohol helps with emotional upset.
This is of course a lie. By constantly driving the brain into an aversive state, alcohol alone can cause depression and anxiety. In addition, it turns out to be neurotoxic, killing brain cells and thereby undermining our ability to recover. It also has a long list of other negative effects on the body, ranging from liver to the heart, our arteries, the pancreas and virtually every cell in the body, all of which conspire to make us feel ill.
To really understand why alcohol keeps us drinking it in these situations, we have to turn to its effect on dopamine. Dopamine signals when things are better than expected. This error in prediction can be used to learn by a variety of different brain areas. Hey - something happened that was better than we thought. Let's make sure we remember that and see if we can repeat it. World Health Organisation. The alcohol fact sheet.
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Management of comorbid bipolar disorder and substance abuse. Journal of Clinical Psychiatry. Neurotoxicity Research. Like Comment. Facebook Twitter LinkedIn. Copy the link. Decreases dopamine activity B. Decreases serotonin activity C. Stimulates muscarinic acetylcholine receptors E. Stimulates N -methyl-D-aspartate excitatory glutamate receptors The answer is C. You may also be interested in Harrison's Podclass episodes with guest Dr.
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