[ad_1]
Operating on myelin
Marathon runners’ myelin ranges within the mind briefly dwindled within the days after a race. The discovering means that this fatty tissue that insulates nerve cells could also be an vitality supply for the athletes, Meghan Rosen reported in “Mind tissue might assist gas marathoners” (SN: 11/18/23, p. 16).
Reader Julian Younger puzzled whether or not myelin ranges may additionally drop in folks on a restrictive weight loss plan such because the low-carb keto weight loss plan or in individuals who expertise low blood sugar ranges for lengthy durations.
It’s unknown whether or not ketogenic diets have an effect on myelin ranges. Such diets “usually don’t trigger clinically related hypoglycemia,” so sufficient glucose stays within the physique to gas mind cells, says neurologist Russell Swerdlow of the College of Kansas Faculty of Medication in Kansas Metropolis. Nonetheless, excessive calorie restriction, similar to that skilled by folks with anorexia nervosa, can lower myelin ranges within the mind, says Carlos Matute, a neurobiologist on the Achucarro Basque Heart for Neuroscience and the College of the Basque Nation in Leioa, Spain.
Reader Kimberly Barden requested whether or not the marathoners’ myelin loss is likely to be linked to the phenomenon generally known as runner’s excessive.
Runner’s excessive has no apparent relationship with myelin loss, Matute says. The phenomenon “is related to the discharge of sure neurotransmitters and endorphins within the mind. This characteristic prompts reward mind circuits that generate a state of euphoria and well-being,” he says.
Past copy
Chimpanzees in Uganda are the primary identified instance of nonhuman primates within the wild to expertise menopause and stay properly previous their reproductive years. The discovering raises questions on how the hormonal modifications developed, Bruce Bower reported in “Menopause impacts wild chimps too” (SN: 11/18/23, p. 8).
In people, the ovaries usually cease releasing eggs throughout menopause. Reader Gerry Beard needed to know whether or not the identical is true for the chimps. Do the animals additionally undergo signs similar to sizzling flashes and temper swings?
Chimp ovaries additionally cease releasing eggs throughout menopause, says UCLA evolutionary anthropologist Brian Wooden. It’s unknown whether or not the Ugandan chimps skilled sizzling flashes or temper swings. However the primates had low ranges of estrogen and progestin, in addition to excessive ranges of follicle-stimulating hormone and luteinizing hormone — physiological modifications which can be related to numerous menopausal signs in people, Wooden says.
Stem cell curiosities
A newfound kind of stem cell within the backbone secretes a protein that pulls most cancers cells. The invention may clarify why cancers that unfold to different physique elements, similar to breast most cancers, preferentially goal the backbone, Meghan Rosen reported in “Spinal stem cells lure breast most cancers” (SN: 11/18/23, p. 14).
An nameless reader requested why this biochemical signaling exists.
It’s unclear why these stem cells within the backbone are higher at attracting most cancers cells than stem cells in different elements of the skeleton, just like the limbs, says pathologist Matthew Greenblatt of Weill Cornell Medication in New York Metropolis. Presumably, the backbone stem cells produce the tumor-attracting protein, known as MFGE8, at excessive ranges for causes apart from to draw most cancers cells, he provides.
It’s probably that the protein has a number of capabilities within the backbone, Greenblatt says. “We do know that MFGE8 acts on skeletal cells to manage bone mass, so maybe the impact of MFGE8 to draw tumor cells displays a co-option of this pathway,” he speculates.
“From one other perspective, we all know that the backbone is superb at retaining blood-forming stem cells, even when chemotherapy or different elements deplete [the cells] at different skeletal websites,” Greenblatt says. It’s potential that the pathways that permit the backbone to be a haven for blood cell formation are by some means co-opted by most cancers cells.
[ad_2]