An interesting experiment conducted by researchers at the Universities of Aalto and Helsinki clarifies a bit how mammals perceive the changes in light between night and day in relation to their visual system. In particular, the study shows that finding an object, such as the right way or a way out, when you are in the dark also depends a lot on the internal clock.
Researchers have in fact learned that mice in the pitch black of the night tended to look for light, and therefore a way out, almost independently of the visual system but rather dependent on how the brains processed the signals at night. The results, which according to the press release presenting the study, which appeared in Current Biology, would be “exciting” for the neuroscience sector, show how the biological time of our body can also alter our sensory processing.
The so-called internal clock, which causes different species of animals to behave differently depending on whether it is day or night, has been known for some time and it seems that almost every organ we have has its circadian rhythm, primarily the eyes.
“Our research group is able to connect whether a mouse can find a dim light in the dark to the underlying retinal nervous signals of the mouse at the limit of vision sensitivity,” reports Petri Ala-Laurila, one of the researchers involved in the experiment and one of the authors of the study. “This allowed us to explore how the day/night cycle changes the mouse’s visual capacity, both at the neural circuit level and up to the behavioral responses at the limit of vision sensitivity”.
“It is exciting now to show that even in the simplest tasks – finding light in the dark – animals can use very different behavioural strategies and, in addition, we are able to quantify the day/night differences in them”, reports Sanna Koskela, a PhD student at the University of Helsinki and the first author of the study.