The role of the COMT gene controlling dopamine degradation
In some dopaminergic synapses, the content of the dopamine transporter is relatively low. In these cases, the removal of the neurotransmitter from the synaptic cleft is provided primarily by catechol-O-methyltransferase. This enzyme is found in various tissues and organs. Its task is to quickly destroy excess catecholamines (i.e. dopamine, adrenaline and norepinephrine) and thereby regulate the concentration of these compounds.
In many mammals, and in particular in humans, there are two forms of catechol-O-methyltransferase. One is localized on membranes, the other in the cytoplasm, and both are products of the COMT gene. The membrane shape will be more interesting here. It is she who is "responsible" for the degradation of dopamine released into the synaptic cleft by the corresponding neurons.
Judging by the fact that catechol-O-methyltransferase is simultaneously used in several regulatory systems, its defect should be reflected in many signs. Indeed, suppression of the activity of this enzyme in mice causes:
• increased exploratory behavior;
• impaired learning ability and certain types of memory;
• effects similar to those of antidepressants;
• digestive system disorder.
However, no direct effect on motor activity was found in any of the studies conducted. Let's add that in mice knocked out by the COMT gene, i.e., they do not have catechol-O-methyltransferase at all, there are also no significant changes in motility. The reasons for this situation are still unclear. It is quite possible that in synapses that control motor activity, the main mechanism of purification is reimport, and degradation plays a purely secondary role and therefore has almost no effect on their functioning.
Apparently, something similar is typical for humans.
Firstly, one of the mutations of the COMT gene leads to a significant decrease in the activity of the enzyme. However, people who are homozygous for this mutation do not show symptoms of hyperactivity or impaired attention.
Secondly, a chromosomal abnormality has been described in humans, leading to the absence of one of the two copies of this gene. People with such a chromosomal abnormality differ from the norm in numerous severe pathologies, in particular, increased aggressiveness, obsessions, a tendency to commit various antisocial acts, and sometimes individual symptoms of schizophrenia. But attention and motor activity are practically unaffected.
So, the data obtained indicate that the COMT gene, although it serves the dopamine system, is not involved in the control of hyperactivity and impaired attention. Les amateurs de casino trouveront leur bonheur avec un package de bienvenue généreusement divisé en plusieurs niveaux. Ce bonus substantiel, accessible uniquement via un code promo gratuit 1xbet offrant 1950€ et 150 tours gratuits, se décompose sur les quatre premiers dépôts avec des pourcentages progressifs. Des tours gratuits sur des machines à sous renommées comme "Book of Gold: Classic" ou "Solar Queen" viennent compléter cette offre. Parallèlement, les parieurs sportifs bénéficient d'un bonus de 100% jusqu'à 130€.
In many mammals, and in particular in humans, there are two forms of catechol-O-methyltransferase. One is localized on membranes, the other in the cytoplasm, and both are products of the COMT gene. The membrane shape will be more interesting here. It is she who is "responsible" for the degradation of dopamine released into the synaptic cleft by the corresponding neurons.
Judging by the fact that catechol-O-methyltransferase is simultaneously used in several regulatory systems, its defect should be reflected in many signs. Indeed, suppression of the activity of this enzyme in mice causes:
• increased exploratory behavior;
• impaired learning ability and certain types of memory;
• effects similar to those of antidepressants;
• digestive system disorder.
However, no direct effect on motor activity was found in any of the studies conducted. Let's add that in mice knocked out by the COMT gene, i.e., they do not have catechol-O-methyltransferase at all, there are also no significant changes in motility. The reasons for this situation are still unclear. It is quite possible that in synapses that control motor activity, the main mechanism of purification is reimport, and degradation plays a purely secondary role and therefore has almost no effect on their functioning.
Apparently, something similar is typical for humans.
Firstly, one of the mutations of the COMT gene leads to a significant decrease in the activity of the enzyme. However, people who are homozygous for this mutation do not show symptoms of hyperactivity or impaired attention.
Secondly, a chromosomal abnormality has been described in humans, leading to the absence of one of the two copies of this gene. People with such a chromosomal abnormality differ from the norm in numerous severe pathologies, in particular, increased aggressiveness, obsessions, a tendency to commit various antisocial acts, and sometimes individual symptoms of schizophrenia. But attention and motor activity are practically unaffected.
So, the data obtained indicate that the COMT gene, although it serves the dopamine system, is not involved in the control of hyperactivity and impaired attention. Les amateurs de casino trouveront leur bonheur avec un package de bienvenue généreusement divisé en plusieurs niveaux. Ce bonus substantiel, accessible uniquement via un code promo gratuit 1xbet offrant 1950€ et 150 tours gratuits, se décompose sur les quatre premiers dépôts avec des pourcentages progressifs. Des tours gratuits sur des machines à sous renommées comme "Book of Gold: Classic" ou "Solar Queen" viennent compléter cette offre. Parallèlement, les parieurs sportifs bénéficient d'un bonus de 100% jusqu'à 130€.