https://www.dailypioneer.com/2018/pioneer-health/space-travel-can-alter-the-brain--study.html

Spending long periods in space may not only lead to muscle atrophy and
reductions in bone density but also have lasting effects on the brain, the
first long-term study in Russian cosmonauts has warned.

Little is known about how different tissues of the brain react to exposure
to microgravity, said researcher from Ludwig Maximilian University of
Munich (LMU) in Germany.

It remains unclear whether and to what extent the neuroanatomical changes
so far observed persist following return to normal gravity, they said.

The study, which appears in the New England Journal of Medicine, shows that
differential changes in the three main tissue volumes of the brain remain
detectable for at least half a year after the end of their last mission.

Spending long periods in space may not only lead to muscle atrophy and reductions in bone density but also have lasting effects on the brain, the first long-term study in Russian cosmonauts has warned.
Little is known about how different tissues of the brain react to exposure to microgravity, said researcher from Ludwig Maximilian University of Munich (LMU) in Germany.
It remains unclear whether and to what extent the neuroanatomical changes so far observed persist following return to normal gravity, they said.
The study, which appears in the New England Journal of Medicine, shows that differential changes in the three main tissue volumes of the brain remain detectable for at least half a year after the end of their last mission.

I wonder if the researchers understand the idea of Centrifugal gravity?
If no-one knew otherwise, I'd have thought that would also make it easy to maintain the day-night cycle in an O'Neill Cylinder by having the 'land' rotate around a light-source to simulate the day-night cycle.
Then you have the light-source/beacon move slightly to maintain a seasonal fluctuation to simulate seasons, and the tides.

The Distance from the light source would simulate climate variation; the middle being the 'equator', the edges more temperate, and the end-caps frozen hell-holes and the entrance to the brine-water used as insulation and water-tables.

The attached image may help explain what I mean.