Cells divide. Cells divide and replace old or damaged cells. This is why biologists wonder how old are cells in our body, in an organism. One general idea is that nerve cells (neurons) are old, while other cells in the body are relatively young and they regenerate throughout an organism’s lifetime. But, by any chance, could there be other organs that have cells as long-lived as neurons in the brain?

Since most neurons are not replaced during the lifespan, researchers are able to use them as an “age baseline” to compare other non-dividing cells. That is exactly what scientists at Salk Institute did. They combined electron isotope labelling with a hybrid imaging method (MIMS-EM). This is to visualise and quantify cell and protein age and turnover in the brain, pancreas and liver in young and old rodent models. They found that, as was to be suspected, neurons are as old as the organism.

Yet, surprisingly, the cells that line blood vessels (endothelial cells) are also as old as neurons. This means that some non-neuronal cells do not replicate or replace themselves throughout the lifespan.

SNEAK PEEK

1. One-hit wonders

A study of the careers of 1,512,472 actors and 896,029 actresses around the world (from 1888 onward) found that one-hit wonders are the norm rather than the exception as long careers with lots of jobs are rare — in times of scarcity of resources. Who conducted the study?

1. Mathematicians from Queen Mary University

2. The 2.5 bio-barrier

We can burn calories only at 2.5 times their resting metabolic rate. And then the body starts to break down its own tissues to make up for the caloric deficit. Not even the world’s fastest ultra-marathoners can surpass this limit. Who thus defined the realm of what’s possible?

2. Evolutionary anthropologist Herman Pontzer

3. Tension in music

A single note played continuously would totally lack dissonance and be uninteresting to our ears. A highly complex piece of music in general is not really pleasing. Most music, across time and cultures, exists in that tension between the two extremes. Who noted the tension?

3. Jesse Berezovsky (Case Western Reserve University)

4. Poor kangaroos!

A temperature increase as small as a half-degree Celsius may shrink northern Australian kangaroos’ geographic ranges. Just two degrees of increase may shrink the ranges by 48% and a six-degree increase might shrink them by 96%. Who noted the large-scale impact?

4. Euan G. Ritchie, Elizabeth E. Bolitho (JCU, Australia)

5. What’s inside counts

A planet’s atmosphere is what researchers study when they look for signs of life. “What’s inside counts” is the latest takeaway. A true picture of habitability must consider how a planet’s atmosphere is linked to and shaped by what’s happening in its interior. Who claimed so?

5. Anat Shahar & team (Carnegie Institution for Science)

6. Having six fingers

Polydactyly. Some people are born with extra fingers or toes. Six-fingered people can perform movements with one hand in contexts where five-fingered people would need two hands. Dedicated areas in the sensorimotor brain areas see to it. Who spotted these areas?

6. Dr Carsten Mehring (University of Freiburg)

7. More than bread

An “odd” Late Bronze Age deposit from Austria yielded dough rings comparable to Italian tarallini. And there was a larger number of clay loom weights, ring-shaped, along with them there. Who suggested that “prehistoric bakers produced so much more than just bread?”

7. Andreas G. Heiss (Austrian Archaeological Institute)

8. Brush your teeth!

Bacteria that cause gum inflammation (gingivitis) can move from the mouth to the brain. They produce a protein that destroys nerve cells in the brain, which in turn leads to loss of memory and ultimately to Alzheimer´s. Who discovered DNA-based proof for this turn of events?

8. Dr Piotr Mydel (University of Bergen)

9. Starting at nine

At about the age of 9, the positive reasons for exercising (it’s fun, it’s good for health) begin to wane in children, being replaced by other concerns (score high marks, polish one’s social image). Who called for prompt action to stop a sedentary lifestyle starting at an early age?

9. UNIGE psychologist Julien Chanal

QUIZ No. 906

1. Who predicted a substantial downsizing of birds and mammals over the next 100 years?

– Rob Cooke
– Dr Margaret Bryan Davis
– Robert Fiske Griggs

1. Rob Cooke

2. “To put it simply, without the Moon there probably would be no life on Earth.” Who said it?

– Marie Henri Andoyer
– Victor H. Ambartsumian
– Thorsten Kleine

2. Thorsten Kleine

3. Who saw curiosity as a deep-rooted desire to resolve uncertainty, heedless of any harm?

– Bowen Ruan
– Clyde Hamilton Coombs
– Milton Hyland Erickson

3. Bowen Ruan

4. Who urged his country’s government to vastly publicise the health risks of cell phone use?

– Joel M. Moskowitz
– Anastasiya Pocheptsova
– Rosellina Ferraro

4. Joel M. Moskowitz

5. Who led China to its first X-ray tube and was persecuted during the Cultural Revolution?

– Hongjia Huang
– Xiangzhong “Jerry” Yang
– Zhou Tongqing

5. Zhou Tongqing