Brain | human animals | neurons | intelligence

Interesting comment of a researcher regards animals with larger brain and cortical neurons as they compare to the human brain, which may explain why humans retain their vastly superior intelligence despite differences in brain size, it appears cortical neuron count can still define the difference:

Despite the enormous number of neurons in the elephant cerebellum, its cerebral cortex, which is twice the size of ours, has only one third of the neurons in an average human cerebral cortex. Taken together, these results suggest that the limiting factor to cognitive abilities is not the number of neurons in the whole brain, but in the cerebral cortex (to which I would add, “provided that the cerebellum has enough neurons to shape activity in the cerebral cortex”).

We don’t have data on whales yet, but that research is underway in our lab – along with research on carnivores, who we predict to have more neurons than the large artiodactyls that they prey upon.-https://intelligence.org/2014/04/22/suzana-herculano-houzel/

Excerpt from an old article on CR relating to humans

“Speaking of humans,” Fontana added, “if you are lean because you are exercising, of course you are doing good, because you’re preventing types of diabetes, some kinds of cardiovascular disease and maybe some types of cancers. But the data suggest that calorie restriction is more powerful. And the people on C.R. are more powerfully protected from diseases than the exercisers.”

Fontana connected his point to his continuing observations of some Calorie Restriction Society members. “In terms of cardiovascular diseases — the No. 1 cause of death; 4 out of 10 people die of it in the U.S. and Europe — we know that they will not die of cardiovascular death,” Fontana said. His subjects have cholesterol around 160, blood pressure around 100 over 60, high HDL, low triglycerides and very low levels of inflammation. “So these people won’t develop these diseases,” he said. “And I think that’s an important finding. Because every day doctors are publishing hundreds of papers on circulation research and medications that are lowering blood pressure or cholesterol by a small bit. And here we have such a powerful intervention that is basically cleaning out the arteries.” At Tufts, Susan Roberts, the lead investigator, echoed this position, saying that the study will probably have greater effects than the average clinical trial. “I don’t know why anyone would take drugs when they could do something like this,” Roberts said, referring to Calerie.-link

A nice article regarding CR in humans, this is only a small interesting bit.

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Calorie Restriction study comments

Regards humans in history. Humans present a very large population far larger than that of any study in CR. The greater number of centenarians in some populations has been attributed to moderate CR.

It is also likely that some humans may exhibit mutations conferring the benefits of CR, we would have to look at the gene expression of centenarians and supercentenarians to see if it is similar or not to that caused by CR. If the gene expression profiles are similar, even if only in some, it would be probable evidence for CR working in humans.

Also from what I've heard CR can work in some species of rodents all the way down to 50% and is rumored could work down at even lower levels if not for death by starvation. IF this is true a CR-mimetic could in theory break the 50% limit when it comes to changes in gene expression and might allow for even longer lifespan..

As for these two studies it would be interesting to see what the weights of the primates were compared to wild animals. It may be that in both cases the CR was too moderate, and both the CR and control fell within normal or slightly less than normal consumption levels for these animals.-fightaging

Also I should add regards the primate studies it would be interesting to note protein intake, and whether there was protein supplementation in the feed as it appears some primates require reduced protein intake for some of the effects of CR(IGF-1 levels)-link

 IT has to be seen what the normal levels of protein are for the animal in the wild, even if the calorie reduction also reduced protein, it may still have resulted in higher than normal protein intake for this type of animal.

It would also have to be seen the type of protein fed,  some types are said to raise IGF-1 which may mean that even the reduced IGF-1 might not have matched or gone below wild type.

Comment regarding negative result on primate studies, and human history potential for CR being implemented and effective as well as possible genetics mimicking CR.