‘Brain switches’ that control male urges to fight and have sex are spotted in mice – and could lead to future treatments for psychiatric disorders
- Scientists have found so-called MPN-signaling cells control sexual activity levels
- Similar cluster called VMHvl-signaling cells involved in controlling aggression
- When signals are amplified or diminished in mice the behaviour also changes
- Researchers do not know if the same network exists in humans but are hopeful the findings can one day lead to treatments for psychiatric disorders
Two types of brain cell have been found in mice which control aggression levels and sexual desire.
The cells are involved in allowing two regions of the brain – the posterior amygdala and the hypothalamus – to communicate.
A study from New York University found that interfering with these pathways significantly alters mouse behaviour.
It is hoped the findings of the research could lead to future treatments for people with psychiatric disorders.
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Two types of brain cell have been found in mice which are involved in triggering aggression and elevating sexual desire. Scientists found these cells are directly involved in how aggressive a male is and how much he tries to have mate (stock)
The scientists took 100 male mice and observed their levels of mounting and fighting and tracked their neural signals.
MPN-signaling cells were most active during sex, while VMHvl-signaling cells were most active during confrontations with other males.
The researchers then suppressed and amplified the neural activity of these cells to see the role they played in behaviour.
The cells involved in aggression and sexual activity are found in the posterior amygdala and try and communicate with the hypothalamus. Interfering with these pathways significantly alters behaviour of a mouse, scientists found
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When so-called MPN-signaling cells in the amygdala were prevented from sending a message to the hypothalamus, mice suddenly became less interested in mating.
Whereas when VMHvl-signaling cells were blocked from sending messages to the hypothalamus from the amygdala, the mice become far less aggressive.
When MPN signals were amplified instead of squashed, male mice became sexually supercharged and pursued unresponsive females in a desperate bid to mate.
Boosting VMHvl signals had the same exaggerated response for aggression which manifested itself as unprovoked attacks on female mates and familiar males.
‘Our findings provide new insights into the crucial role played by the posterior amygdala in driving male social behaviors like sex and aggression,’ says lead study author Dr Takashi Yamaguchi from NYU Langone Health.
Little is known about the posterior amygdala and the role it plays in regulating thoughts and behaviours.
The latest findings, Dr Yamaguchi believes, reveal how important this small part of the organ is, as it clearly exerts ‘tremendous’ influence over social behaviour.
While this finding is clear in mice brains, it remains unknown if the same relationship exists in humans.
However, the authors are encouraged by the findings and are hopeful that it could one day lead to therapeutics for people suffering with psychiatric disorders.
The research is published in the journal Nature Neuroscience