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The physics of Turkey’s devastating earthquakes; being a light-speed photon; and more. Plus: do whales have culture? forget what you know about emotions; and more. [View in browser]( | [Join Nautilus]( June 27, 2023   Did a friend forward this? [Subscribe here](. This Tuesday, your FREE member newsletter includes the week’s top science news and one full story, below, from The Porthole. Enjoy! [READ NAUTILUS](   DISCOVERIES The Top Science News This Week   [Urban Visual Intelligence: Uncovering Hidden City Profiles with Street View Images]( Google’s street images reveal more than you might expect about a city’s health. [PNAS→](   [Multi-Scale Rupture Growth With Alternating Directions in a Complex Fault Network During the 2023 South-Eastern Türkiye and Syria Earthquake Doublet]( The physics of where the devastating earthquake in Turkey came from. [Geophysical Research Letters→](   [Why Are There Six Degrees of Separation in a Social Network?]( It comes down to the all-too-human aspiration to belong. [Physical Review X→](   [Animating Irony: The Force of Irony in Online and Offline Political Movements]( “Irony can generate surpluses of meaning, cultivate spaces of play and freedom from responsibility, and amplify the felt potentiality of ideas through memetic repetition.” ([Non-Paywall PDF]() [Public Culture→](   [What Is It Like to Be a Photon Traveling at Light Speed?]( For one thing, you never run short on time. [Big Think→](   [The Surprise of Splitting Electrons]( The particles somehow retain a collective memory. [The Wall Street Journal→]( Experience the endless possibilities and deep human connections that science offers [SUBSCRIBE TODAY](   [Join Us at the MB Summit of Minds]( Immerse yourself in the [3-day ideas festival](with nature at its heart. Enjoy innovative sessions and workshops on the science of nature and nature-based solutions at the top of the French Alps. [GET TICKETS](   From The Porthole   [NEUROSCIENCE]( [Which Sex of Mouse Should You Ask for Directions?]( The sex stereotypes built into animal research. BY KRISTEN FRENCH   Hormonal: It’s shorthand for erratic, volatile, unpredictable female behavior. It’s such a powerful sex stereotype that even lab rats could not escape its reach. For decades, behavioral neuroscience excluded female mice because they assumed estrus cycles made them too inconsistent to study. But the scientists had no evidence to back this up—and over the past decade research has shown [repeatedly]( that it’s [wrong](. Then earlier this year, psychology researcher Rebecca M. Shanksy of Northeastern University and a team of colleagues published [findings]( that suggested male mice may actually behave less predictably than females under certain conditions—and that individual personality plays a bigger role in behavior than sex or hormonal status, anyway. The news made a [splash](. One of the deepest held stereotypes is that males are better at spatial learning. We caught up with neuroendocrinologist [Margaret McCarthy]( to talk about how hormones shape human behavior and stereotypes in scientific research. She’s the director for the program in neuroscience at the University of Maryland School of Medicine and her work has significantly advanced our understanding of sex differences and the brain. Does neuroscience research over-emphasize the importance of female hormones to behavior? Well, what Shanksy’s study showed is that we have to consider the importance of the individual to behavior more. Does individual personality just play a significant role in locomotive and spontaneous behavior, which is what Shanksy and her colleagues studied, or in other more motivated cognitive tasks like motor learning or fear responding or drug addiction where we talk about all of these sex differences? I would love to know. [Want more stories like this? Join Nautilus]( Don’t get me wrong: Hormones are enormously powerful modulators of the brain and behavior. And that’s what I have devoted my career to, the field of neuroendocrinology. But if you look at a lens with a filter on it, you will always see the filter. One of the big beefs I have whenever I participate in large group manuscripts about the importance of sex differences is that everybody’s always focusing on this reproductive active adult. But humans live an enormous amount of our lives in a non-reproductive status—not just in post-menopause, but childhood, and there’s no steroid hormones around at that time. Then we have the reproductive years. But particularly in women, we can have another 30 years of life without high levels of circulating steroid hormones. We can have a completely different hormonal profile during lactation. But we always study this menstrual cycle female and high testosterone male. That’s the default. Are other gender stereotypes baked into basic neuroscience research? I would say that one of the deepest held stereotypes is that males are better at spatial learning. And a lot of that has to do with the use of the Morris Water maze, which is where the rat has to swim out to a platform to get out of the water. Studies have clearly demonstrated that stress is a huge component of the response, and if you remove the stress by allowing the animals to pre-condition to the pool, then females perform just as well as males. Also, males and females use different strategies, different cues. Females stick around the edges more, and that makes it take longer to get to the platform. Really, the dumbest thing you can do is swim straight out into open water to reach the platform. There could be sharks out there! So the females are smart. They stick to the edges and then they dart over to the platform. Everybody’s always focusing on this reproductive active adult. Now, fascinatingly, the first spatial learning tasks were designed way back in like the 1920s, and they had a whole lot of them, and they still do. There’s a task with eight-arm radial mazes. There’s another task that’s based on remembering where a food pellet is down a long corridor. There are others that are also about fear and recall. They put the rats on a large open platform with escape holes and task them to remember which one is a real escape and which one is a dead end. So there are all these different ways to test them on spatial learning. But back when they first designed all of these different tasks, there was only one that routinely showed a sex difference with males performing better. And that was the Morris Water maze, and it became the gold standard for spatial learning in rodents. People use the test to examine the effects of traumatic brain injury, birth hypoxic injury, neuroinflammation, or any other cognitive impairment: You’ve been exposed to lead, or some other toxicant. I would love to see the kind of analysis that Shansky and colleagues did applied to exploration in the Morris Water maze. How widespread is the exclusion of females in animal research? Shansky and her colleagues noted in their paper that it’s really behavioral neuroscience where females were actively excluded. You can see it happen from the 1990s in the first studies about the synaptic plasticity in the hippocampus. But the field of immunology has been largely dominated by female mice. You can get more female mice in a cage, because the males fight, and so you save on your per diem. They just think, “Oh, it’s all the same.” It’s very funny. When sex as a biological variable first came out, I talked to my colleagues in the microbiology and immunology departments and I was telling them, “You’re gonna have to start thinking about male mice,” and they just hated it. One guy finally goes, “You don’t understand. The males are completely different.” Kristen French is an associate editor at Nautilus. Lead image: Oleg Kozlov / Shutterstock More from The Porthole: • [Through the microscope, bacterial colonies look like bustling cities]( • [Do whales have culture?](   BECOME A MEMBER [The Dark Side of Storytelling]( [Issue 49 of Nautilus]( features “The Comet Year,” in which emergency physician Clayton Dalton meditates on the nature of the divergent storytelling around the causes of COVID-19—and what our fractured standards for truth could mean for the future. [GET NAUTILUS IN PRINT]( Thanks for reading. [Tell us](mailto:brian.gallagher@nautil.us) your thoughts on today’s note. 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