Fall and winter cause many people to fall short of winter, and even depressed. On the contrary, the symptoms disappear with the advent of summer. These seasonal mood disorders are often successfully treated with light therapy. Although its positive effect has been demonstrated, it has not yet been clear what molecular mechanism makes the brain adapt.
Alessandra Porco Research at the University of South Carolina Effects of a change in light on mental health. For this Female and male mice were exposed to long periods of light (nineteen hours of light, five hours of dark) or short (five hours of light, 19 hours of dark) for a period of 15 days. This is similar to exposure in areas in the north where winter depressions are common.
dopamine
Previous research has already shown that a neurotransmitter in the brain network called SCN (Supracural Nucleus)-PVN (Paraventricular Nucleus) is expressed differently depending on the season. SCN is the particle in our brain, more specifically in the hypothalamus, where our biological clock resides. Thousands of neurons coordinate the circadian or 24-hour rhythms in our bodies based on the light and dark cycle.
Porcu: We have seen that the switching of neurotransmitters in the SCN-PVN axis in mice is the same as in humans and we were also able to unravel the mechanism behind it. NMS (neuromedin S) neurons, which play an essential role in circadian or circadian rhythms, alter their neurotransmitter and gene expression in response to light and darkness. This regulates the activity of dopamine cells in the PVN, which in turn direct our mood and stress responses. NMS neurons are expressed only in the hypothalamus. Potential new treatments for seasonal depression could also interfere with this.
