Author Archives: Bix

Cuttlefish Have Better Memories Than Humans

Cuttlefish are able to remember what, where, and when specific events happened up until their last days of life. Researchers suggest this is the first evidence of an animal whose memory of specific events does not deteriorate with age, unlike our own.

Photo source: Hakai Magazine, “When exposed to a variation of the classic psychological marshmallow test, cuttlefish showed they were capable of self-control.” Photo by Biosphoto/Alamy Stock Photo

Cuttlefish Remember Details Of Their Last Meal, Study Finds, The Guardian, 18 August 2021

Cuttlefish have one of the largest brains among invertebrates and can remember what, where, and when specific things happened right up to their final days of life, according to new research.

The cephalopods – which have three hearts, eight arms, blue-green blood, regenerating limbs, and the ability to camouflage and exert self-control – only live for roughly two years.

As they get older, they show signs of declining muscle function and appetite, but it appears that no matter their age they can remember what they ate, where and when, and use this to guide their future feeding decisions, said the lead study author, Dr Alexandra Schnell from the University of Cambridge.

This is in contrast to humans, who gradually lose the ability to remember experiences that occurred at a particular time and place with age – for instance, what you ate for lunch last Wednesday. This “episodic memory” and its deterioration is linked to the hippocampus, a seahorse-shaped organ in the part of the brain near our ears. Cuttlefish, meanwhile, do not have a hippocampus, but a “vertical lobe” associated with learning and memory.

During training, the performance of both groups was comparable, she said. “In the test phase, the older cuttlefish (the equivalent of a human in their 90s) actually outperforms the younger cuttlefish.”

Malcolm Kennedy, professor of natural history at the University of Glasgow, said it was refreshing to come across another case where aspects of animal cognition can be as advanced as our own, despite huge evolutionary time separation and a nervous system constructed completely different from ours.

The pedestal upon which humans place themselves in terms of neurological abilities continues to crumble. It is just that other types of animals perform similar functions differently,” he said.

Going To Bed Hungry Can Disrupt Sleep

In this rat study, a hormone (ghrelin) that causes feelings of hunger when food is restricted and spurs the urge to eat, suppressed sleep:
Ghrelin-Induced Sleep Responses In Ad Libitum Fed And Food-Restricted Rats, Brain Research, May 2006

Sleep responses and motor activity after central administration of 0.2, 1, or 5 μg ghrelin in free-feeding rats as well as in feeding-restricted rats (1 μg dose) were determined.

Light onset injection of ghrelin suppressed non-rapid-eye-movement sleep (NREMS) and rapid-eye-movement sleep (REMS) for 2 h. In the first hour, ghrelin induced increases in behavioral activity including feeding, exploring, and grooming and stimulated food and water intake. Ghrelin administration at dark onset also elicited NREMS and REMS suppression in hours 1 and 2, but the effect was not as marked as that, which occurred in the light period. In hours 3–12, a secondary NREMS increase was observed after some doses of ghrelin. In the feeding-restricted rats, ghrelin suppressed non-rapid-eye-movement sleep (NREMS) in hours 1 and 2 and rapid-eye-movement sleep (REMS) in hours 3–12.

Data are consistent with the notion that ghrelin has a role in the integration of feeding, metabolism, and sleep regulation.

Hypothalamic Orexin Neurons Regulate Arousal According to Energy Balance in Mice, Neuron, June 200
(Orexic neurons are stimulated by ghrelin.)

Mammals respond to reduced food availability by becoming more wakeful.

The idea that ghrelin could disturb sleep was captured by mainstream media:
Trouble Sleeping? Some Bedtime Snacks Can Help You Sleep , WebMD, May 2008

Why Hunger Disrupts Our Sleep
This relatively new research focuses on leptin and ghrelin, two metabolic hormones that scientists discovered only during the last decade. When we eat, leptin signals that the body is satisfied, while ghrelin stimulates hunger. Researchers speculate that if we have enough leptin to suppress the secretion of ghrelin, we’ll sleep through the night without awakening to eat. “They act in see-saw fashion, counterbalancing each other,” says Culebras. “If the balance is thrown out of order, it may result in subtle signs that awaken us.”

Ghrelin is a fairly recent discovery. It does more than just induce hunger. Scientists are still learning.
Ghrelin, Molecular Metabolism, June 2015

The gastrointestinal peptide hormone ghrelin was discovered in 1999 as the endogenous ligand of the growth hormone secretagogue receptor. Increasing evidence supports more complicated and nuanced roles for the hormone, which go beyond the regulation of systemic energy metabolism. … In recent years, ghrelin has been found to have a plethora of central and peripheral actions in distinct areas including learning and memory, gut motility and gastric acid secretion, sleep/wake rhythm, reward seeking behavior, taste sensation and glucose metabolism.

Schematic on ghrelin’s physiological effects:

And this one for the graphic:
Hypothalamic Neurons That Regulate Feeding Can Influence Sleep/Wake States Based on Homeostatic Need, Current Biology, December 2019

Graphical Abstract:

What Humans See. What Birds See.

Evergreen State College, Archives: Birds

Most birds are tetrachromats or have four types of cone cells; red, green, blue and ultraviolet.* These four types of cones are what allows them to process a wider wavelength spectrum than humans. Their spectrum extends to the UV range of 300-400 nm.

Although birds are not the only ones who have UV vision (fish, amphibians, reptiles, and insects also have the ability), it does provide them with evolutionary advantages. One of the most important functions is orientation. UV vision gives birds an advantage over trichromats and dichromats in being able to identify shapes and objects which facilitates in travel. Another important function is the increased ability to look for food. UV vision allows birds to more easily spot insects, berries, seeds and mammals[8]. Another function is signaling, especially during mate selection. The UV allows birds to differentiate between the desirable and undesirable candidates for mating.

* Humans have only three types of cone cells: blue, green, and red.

All of these images are from This Is How Birds See The World As Compared To Humans And It’s Pretty Amazing , Bored Panda.

Image credits: Klaus Schmitt

On the left is what we humans see, on the right is (probably something like, I mean, who knows, we should ask the bird) what birds see:

Image credits: Unknown

Image credits: Cynthia Tedore

Image credits: Joel Sartore

Image credits: Unknown

Exercise Does Not Lower Cholesterol

Exercise has many benefits. One thing it can’t do is lower cholesterol.

Effects Of The Amount And Intensity Of Exercise On Plasma Lipoproteins, New England Journal of Medicine, November 2002.

Total Cholesterol (mg/dl)

Control Group: Baseline: 205.7, End of study: 208.3
Low-Amount-Moderate-Intensity Group: Baseline: 193.2, End of study: 194.1
Low-Amount-High-Intensity Group: Baseline: 202.3, End of study: 206.4
High-Amount-High-Intensity Group: Baseline: 202.7, End of study: 203.1

LDL Cholesterol (mg/dl)

Control Group: Baseline: 135.8, End of study: 138.2
Low-Amount-Moderate-Intensity Group: Baseline: 121.6, End of study: 125.3
Low-Amount-High-Intensity Group: Baseline: 131.6, End of study: 135.2
High-Amount-High-Intensity Group: Baseline: 130.1, End of study: 128.2

There was some benefit in other less-important lipid fractions. Notably, triglycerides decreased in all exercise groups and HDL improved but only in the high-amount-high-intensity group.

These were 111 sedentary, overweight men and women. They exercised for 8 months. Their total cholesterol didn’t budge.

If you want to lower your cholesterol you have to change your diet.

Men Who Take Vitamin D Increase Their Testosterone Levels. That May Not Be A Good Thing.

Effect Of Vitamin D Supplementation On Testosterone Levels In Men, Hormone and Metabolic Research, March 2011

From abstract:

The male reproductive tract has been identified as a target tissue for vitamin D, and previous data suggest an association of 25-hydroxyvitamin D [25(OH)D] with testosterone levels in men.

Participants received either 83 μg (3,332 IU) vitamin D daily for 1 year (n = 31) or placebo (n = 23).

Mean circulating 25(OH)D concentrations increased significantly by 53.5 nmol/l in the vitamin D group, but remained almost constant in the placebo group.

Compared to baseline values, a significant increase in total testosterone levels, bioactive testosterone, and free testosterone levels were observed in the vitamin D supplemented group [all measures p = 0.001]. By contrast, there was no significant change in any testosterone measure in the placebo group.

Might that extra vitamin D and testosterone improve muscle strength? It doesn’t appear so:

Vitamin D Supplementation Does Not Enhance Resistance Training-Induced Gains In Muscle Strength And Lean Body Mass In Vitamin D Deficient Young Men, European Journal of Applied Physiology, July 2021

In fact:

” … whereas strength gains in chest press and seated row were greater (P < 0.05) in placebo group compared to vitamin D group.”

From Harvard Medical School:

Problems associated with abnormally high testosterone levels in men include:

Low sperm counts, shrinking of the testicles and impotence
Heart muscle damage and increased risk of heart attack
Prostate enlargement with difficulty urinating
Liver disease
Fluid retention with swelling of the legs and feet
Weight gain, perhaps related in part to increased appetite
High blood pressure and cholesterol
Increased muscle mass
Increased risk of blood clots
Stunted growth in adolescents
Uncharacteristically aggressive behavior
Mood swings, euphoria, irritability, impaired judgment, delusions

So, men who take vitamin D will increase their testosterone levels which may make it difficult to sleep and pee, increase risks for prostate cancer and heart attack, and put them in a bad mood. Is that what this says? Vitamin D? So many men are taking vitamin D…

Aerial Footage Of Kiska, Marineland’s Last Surviving Orca Bashing Her Head Against The Wall

This is not easy to watch.

This video was taken on Sept 4th, 2021. Anti-captivity activists entered MarineLand and observed Kiska, their last surviving orca bashing her head against the wall.

But it’s not unlike how we treat lots of animals, especially ones that we eat. CAFO’s (Concentrated Animal Feeding Operations) – the source of most of our beef, chicken, pork, eggs, and dairy food – should be banned.