The daily ebb and flow of hormones in the male body may play a role in shrinking the brain throughout the day, a study hints. After losing volume between morning and evening, the brain resets overnight, starting the cycle again, the research shows.
The study involved scanning a 26-year-old's brain 40 times in 30 days. Each magnetic resonance imaging (MRI) scan was collected at either 7 a.m. or 8 p.m., which is when levels of steroid hormones — namely, testosterone, cortisol and estradiol — are at their highest and lowest, respectively.
