American researchers have studied the mechanisms that produce a feeling of intoxication and have antidepressant effects after a short period of sleep deprivation.
- A sleepless night usually causes an increase in dopamine release in certain brain regions.
- The prefrontal cortex and its dopamine inputs are at the origin of rapid plasticity and antidepressant effects after a brief loss of sleep, according to an American study.
- However, sleepless nights are not the solution to improving mood.
After a sleepless night, you may feel a feeling of dizziness like drunkenness. The body is physically exhausted, but the brain is in great shape due to an increase in dopamine release in certain brain regions. This dopaminergic signal also reinforces the plasticity of neuronal connections, which “rewires” the brain and causes a powerful antidepressant effect for several days.
Greater dopaminergic neuron activity in sleep-deprived subjects
A study recently observed the mechanisms that produce this intoxicating and antidepressant effect. “Interestingly, mood changes after acute sleep loss appear very real, even in healthy subjects (…) But the exact brain mechanisms that lead to these effects remain poorly understood”, explained Professor Mingzheng Wu, lead author of the study and postdoctoral researcher at Northwestern University (United States). This work was published in the journal Neuron.
For the purposes of this research, the scientists caused mild sleep deprivation in mice, which did not have a genetic predisposition to mood disorders. Dopamine neuron activity was then assessed in sleep-deprived rodents and a control group. The researchers then noted that the activity of these neurotransmitters was higher in animals that had experienced brief sleep deprivation, but synaptic plasticity was also reinforced, which helped prevent bad moods.
Insomnia: “the antidepressant effect is transient”
They then studied four regions of the brain responsible for dopamine release: the prefrontal cortex, the nucleus accumbens, the hypothalamus and the dorsal striatum. “We were curious to know which specific regions of the brain were responsible for the behavioral changes (…) We wanted to know if it was a broad, diffuse signal, which affected the whole brain or if it was was something more specialized”, said the Professor Yevgenia Kozorovitskiy, corresponding author of the study and expert in neuroplasticity. Scientists observed that the prefrontal cortex, nucleus accumbens and hypothalamus were involved in the release of dopamine after acute sleep loss.
In order to further refine the results, the team prevented dopaminergic reactions. The antidepressant effect linked to sleep deprivation disappeared when the dopaminergic response was stopped in the medial prefrontal cortex. “This means that the prefrontal cortex is a clinically relevant area in the search for therapeutic targets”noted the Professor Yevgenia Kozorovitskiy.
However, the researcher indicated that sleepless nights are not the solution to improving mood. “The antidepressant effect is transient and we know the importance of a good night’s sleep (…) I would say it is better to go to the gym or go for a walk”she added.
