Male brain is programmed to seek out sex over food
Brain cells specific to men fire up when mates are present and override the need to eat, scientists have found
Published 14/10/2015 | 23:27
It is said that the way to a man’s heart is through his stomach, but a new study suggests that when it comes to sex, food is the last thing on his mind.
Researchers have found that the male brain is hardwired to seek out sex, even at the expense of a good meal, with specific neurons firing up to over-ride the desire to eat.
Intriguingly, women do not have the same neurons, suggesting that sex for females comes secondary to sustenance.
Although the neurons have only been found in the brains of nematode worms, scientists at University College London say that it is likely that similar mechanisms are at work in humans.
And it is proof that male and female brains are wired differently, a controversial subject, which has been argued by scientists and feminists for decades.
Co-author Professor Scott Emmons, from the Departments of Genetics and Neuroscience at Albert Einstein College of Medicine, said: "Though the work is carried out in a small worm, it nevertheless gives us a perspective that helps us appreciate and possibly understand the variety of human sexuality, sexual orientation, and gender identification.
"Although we have not looked in humans, it is plausible that the male human brain has types of neurons that the female brain doesn't, and vice versa. This may change how the two sexes perceive the world and their behavioural priorities."
The team were surprised to find the new cells because the worms have been studied by extensively in the past and it is the first time they have been spotted.
The newly identified neurons have been dubbed MCMs or 'mystery cells of the male'
The worm species used in the study, Caenorhabditis elegans, has two sexes: males and hermaphrodites.
These hermaphrodites are essentially modified females that carry their own sperm and do not need to have sex in order to reproduce.
Scientists conditioned the worms so that when salt was present they realised that they would be starved. Over time, the worms moved away from the salt. However when the salt was present at the same time as a mate, the male worm still moved towards the mate. In contrast, hermaphrodites moved away from the salt even when a mate was present.
It indicated that for males the sex trigger was stronger than the salt.
"Areas of the brain involved in learning display sex differences in many animals, including humans, but how these differences directly affect behaviour is not clear,” said senior author Dr Arantza Barrios of UCL’s Cell & Deveopmental Biology department.
"We've shown how genetic and developmental differences between the two sexes lead to structural changes in the brain of male worms during sexual maturation.
“These changes make male brains work differently, allowing males to remember previous sexual encounters and prioritise sex in future situations."
The research was published in the journal Nature.