Sounds and brain: Brains may “tune” themselves differently in males and females depending on what they hear early in life, suggests a new study in mice, with possible implications for how early sound environments shape later preferences and behaviour.
The research, led by Indian-origin neuroscientist Kamini Sehrawat and Israel Nelken at The Hebrew University of Jerusalem, looked at how young male and female mice responded to sound exposure as pups and how that shaped their choices as adults. The work is published in the journal Cell Reports.
In the experiment, some mouse pups were raised hearing Beethoven’s Symphony No. 9, a classic choice in neuroscience studies, while others grew up in silence or with artificial sounds. When the mice reached adulthood, researchers tested which sounds they preferred to spend time listening to.
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The results showed a striking sex difference. Male mice that had been exposed to Beethoven early in life grew up to show more varied sound preferences, with many displaying a clear attraction to music. But males that had been raised in silence, or with artificial noise, tended to avoid music as adults and showed a stronger preference for silence instead.
Female mice, by contrast, appeared more flexible. Regardless of whether they had been exposed to music, silence or artificial sounds as pups, they showed a broad range of sound preferences as adults, rather than a strong shift towards or away from music.
The team also recorded activity in the auditory cortex, the part of the brain involved in processing sounds. Here, too, the patterns differed between males and females.
In both sexes, mice exposed to music or silence showed suppressed activity in the auditory cortex compared with “naive” control animals that had not had those specific exposures. But when the researchers compared brain activity with behaviour, they again found a sex-dependent effect.
In female mice, stronger neural responses in the auditory cortex were associated with a lower interest in music. In other words, females who had a more muted brain response were more likely to choose music. In male mice, however, there was only a weak link between neural responses and behaviour, suggesting that sound preferences in males may be shaped through different mechanisms.