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Brain activity linked to stress changes chemical codes: Findings may be relevant to other disorders, from autism to PTSD -- ScienceDaily

In the new findings, the researchers studied the change in neurotransmitter identity when rats, which are nocturnal, are exposed to long day lengths. This exposure led to elevated activity of paraventricular (PaVN) neurons in the hypothalamus and by consequence a loss in their expression of dopamine, a neurotransmitter that is linked with many aspects of normal behavior. When the researchers suppressed the elevation of activity that resulted from the long-day exposure, exclusively in the PaVN neurons, they blocked the transmitter switch that would have occurred under these normal light conditions.