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Last week featured a wide range of stories that either made us smile or have a little giggle. We’ve rounded a few of them up for your Monday morning. 

Naked mole-rats speak in dialect

It’s not only humans who can be identified by the diversity of their languages: it turns out naked mole-rats (Heterocephalus glaber) have their own dialects too.

Previous studies have shown that some birds, amphibians and whales are known to have different ‘accents’. Sperm whales (Physeter macrocephalus) in the Caribbean, for example, use different clicking patterns from those in the Pacific. 

Naked mole-rat dialects, on the other hand, appear to be colony-specific. 

“The development of a shared dialect strengthens cohesion and a sense of belonging among the naked mole-rats of a specific colony,” explains Alison Barker, lead author of a new study published in the journal Science. Barker works at the Max Delbrück Center for Molecular Medicine (MDC), Germany.

To analyse the language, the research team recorded a total of 36,190 chirps made by 1966 individuals from seven colonies held in laboratories. The results showed that each naked mole-rat had its own voice. Similarities in the types of sounds were also detected within each colony. 

To test whether the mole-rats recognised their own dialect, the team placed individuals in two chambers connected via a tube, so they could hear each other’s chirpings. If sounds were made by an individual from the same colony, the other mole-rat would give an immediate vocal response. 

“Human beings and naked mole-rats seem to have much more in common that anyone might have previously thought,” concludes author Gary Lewin. “The next step is to find out what mechanisms in the animals’ brains support this culture, because that could give us important insight into how human culture evolved.”

A melody can soothe following surgery

A lot of people will turn to their favourite playlist to get them through troubling times. Whether it be the soothing tones of acoustic guitar and piano, or an upbeat dance track – previous studies have highlighted the benefits of music to relieve stress. 

A Dutch study is adding to that, finding listening to music reduced anxiety and pain following major heart surgery.

The researchers from Erasmus University Medical Centre, in The Netherlands, reviewed the results of 20 studies involving 1169 patients, and data from a further 16 studies involving 987 patients. 

The type of music varied, with each patient choosing their own preferred music, but was generally described as relaxing and free of strong rhythms. Most of the music was provided through headphones.

The pooled data showed that listening to music significantly reduced anxiety and pain after major surgery. 

“Since music intervention has neither risks nor known side effects, but may have a positive effect on patients health outcomes, healthcare professionals should consider providing perioperative music for patients undergoing cardiac surgery,” the authors write in their paper published in the journal Open Heart. 

Domesticated dogs in the Americas 

The first people to settle in the Americas likely brought their own domesticated canine companions, according to a new study. 

An international team of researchers analysed archaeological and genetic records of ancient people and dogs, finding the first people to cross into the Americas before 15,000 years ago were of northeast Asian descent, and were accompanied by their dogs.  

“When and where have long been questions in dog domestication research, but here we also explored the how and why, which have often been overlooked,” says lead author Angela Perri, from Durham University, UK.

The researchers suggest dog domestication likely took place in Siberia before 23,000 years ago. People and their dogs then eventually travelled both west into the rest of Eurasia, and east into the Americas.

“Dog domestication occurring in Siberia answers many of the questions we’ve always had about the origins of the human-dog relationship,” says Perri.

“By putting together the puzzle pieces of archaeology, genetics and time we see a much clearer picture where dogs are being domesticated in Siberia, then disperse from there into the Americas and around the world.”

While the Americas were one of the last regions to be settled, by this same time dogs had been domesticated from their wolf ancestors and were already playing important roles in human societies. 

The researchers suggest this may have all begun due to the harsh climatic conditions across most of Siberia may have served to bring human and wolf populations into close proximity, given their attraction to the same prey.

This increasing interaction may have led to the formation of a relationship between the species that eventually led to dog domestication. 

The work is published in the journal Proceedings of the National Academy of Sciences. 

Three-day old blind mice can recognise mum

The three blind mice nursery rhyme ends badly, with the mice having their tails cut off. This story of three-day-old blind mice features a much happier ending. 

New research out of Princeton University, US, has found that newborn mice have no problem recognising their caregivers – preferring their mothers to unfamiliar mouse mothers. 

First author Blake J Laham put the pups between the caregiving mother and an unrelated mouse mother. At three days old, the mice are pink, hairless and slightly translucent, with poor motor skills. However, this didn’t stop them from rotating themselves to their mother.

They were also found to spend more time pointing their nose towards their caregivers as a sign of recognition and preference. 

The authors found these memories lasted into adulthood, with the mice retaining the ability to recognise their mothers even after being separated for over 100 days. 

The research is published in the journal Cell Press. 

The researchers then examined a region associated with social memory called CA2 in the mouse brain, finding the pups showed more biological markers related to neuronal activity after exposure to their mothers. 

However, “there’s this really fascinating behavioural transition once the animal is weaned,” says Laham. “When the animal is no longer dependent on the caregiving mother, the animal prefers investigating novel mothers.”

Afternoon naps are a brain booster

Those who sneak in a quick nap may have improved mental agility, suggest Chinese scientists. 

They studied 2,214 people aged 60 and over, of which 1,534 enjoyed a regular afternoon siesta, finding a quick nap was associated with better locational awareness, verbal fluency and working memory. 

The researchers studied residents in several large cities around China including Beijing, Shanghai and Xian. The average length of night-time sleep was 6.5 hours for both non-nappers and nappers. The naps were no longer than two hours and taken after lunch. 

“Afternoon napping is considered a component of a healthy lifestyle from a cultural perspective,” the authors explain in their paper published in BMJ. 

“In addition, the prevalence of afternoon napping has been increasing in older adults much more than in younger individuals.”

The scientists suggest sleep may help ward off inflammation in the body, explaining the brain boost.

However, they highlight that a lack of detailed information about napping duration time is limited, with further studies needed to establish cause.