Read on Twitter
Yesterday, I was lucky to attend to a seminar by Dr. Larry Cahill about why sex matters for neuroscience. It was absolutely enlightening and I feel like sharing some of the findings Dr. Cahill stressed during his talk.
One of the key messages is the relatively new (yet obvious) notion that the mammalian brain is influenced by biological sex. I guess that's something easy to understand for, say, undergrads but not that much for biologists who learnt neuroscience back in the 70s.
Actually, this is so important that even the NIH officially issued a biological sex policy not that long ago to avoid the extant bias in the literature favoring the analysis of exclusively male subjects (both in human and in animal studies) https://twitter.com/NIH/status/1082736205320597504
This change was possible thanks to a long list of breakthroughs in the topic such as the description of different patterns of amygdala activation during emotional memory consolidation when comparing men (left) and women (right)
Dr. Cahill and his research team have been building on those findings during the last decades focusing on the role of sexual hormones in cognition and memory. And here's when things get even more interesting.
They first started by focusing on naturally cycling women to test how fluctuating levels of sexual hormones during the menstrual cycle could impact emotional memory.
That lead to a number of publications describing how stress interacts with the menstrual cycle in cognitive processes such as intrusive recollections or emotional memory performance https://pubmed.ncbi.nlm.nih.gov/21353599/ https://pubmed.ncbi.nlm.nih.gov/22101178/
But of course this leads to the next question: "what happens with women taking oral contraceptives?". Contraceptive pills have been around for more than 50 years now with countless women taking them during decades but no one had bothered to take a look at their brains before!
Unsurprisingly, Dr. Larry Cahill has published a wealth of studies documenting the numerous effects contraceptive pills seem to have on stress reactivity, brain structure and activity https://pubmed.ncbi.nlm.nih.gov/25832993/ https://pubmed.ncbi.nlm.nih.gov/23131613/ https://pubmed.ncbi.nlm.nih.gov/24365676/
The understanding of how sex (and sexual hormones) impacts physiology will be crucial for a better understanding of pathological processes. Particularly those that affect differentially men and women such as depression, anxiety and autoimmune disorders, among many others.
I'd like to finish this thread by thanking Dr. Larry Cahill for his wonderful talk and also to all the team behind the Reproductive Mood Disorders T32 training program at @UNC for hosting it
