Light rescues circadian behavior and brain dopamine abnormalities in diurnal rodents exposed to a winter-like photoperiod.

Light rescues circadian behavior and brain dopamine abnormalities in diurnal rodents exposed to a winter-like photoperiod. Brain Struct Funct. 2018 Mar 20;: Authors: Itzhacki J, Clesse D, Goumon Y, Van Someren EJ, Mendoza J Abstract Seasonal affective disorder (SAD), beyond mood changes, is characterized by alterations in daily rhythms of behavior and physiology. The pathophysiological conditions of SAD involve changes in day length and its first-line treatment is bright light therapy. Animal models using nocturnal rodents have been studied to elucidate the neurobiological mechanisms of depression, but might be ill suited to study the therapeutic effects of light in SAD since they exhibit light-aversive responses. Here Arvicanthis ansorgei, a diurnal rodent, was used to determine behavioral, molecular and brain dopamine changes in response to exposure to a winter-like photoperiod consisting of a light-dark cycle with 8 h of light, under diminished light intensity, and 16 h of darkness. Furthermore, we evaluated whether timed-daily bright light exposure has an effect on behavior and brain physiology of winter-like exposed animals. Arvicanthis under a winter-like condition showed alterations in the synchronization of the locomotor activity rhythm to the light-dark cycle. Moreover, alterations in day-night activity of dopaminergic neurotransmission were revealed in the nucleus accumbens and the dorsal striatum, and in the day-night cl...
Source: Brain Structure and Function - Category: Neuroscience Authors: Tags: Brain Struct Funct Source Type: research