Comments on: How Does the Brain Use So Much Energy? Not in Electrical Signals.

By: Brian

Brian — Wed, 16 Sep 2009 23:23:24 +0000

Re: “…and neuroscientists ever since have assumed that mammal brains had the same…” versus “…researchers say we can assume that the results from rats can be applied to human brain cells…”.

Um, wasn’t it their assumptions that led Hodgkin and Huxley (or perhaps their successors) astray? Is making a new assumption wise under the circumstances? I totally get that there’s a reason why Alle would think that this could be extrapolated to all mammals. However when you’re trying to correct a methodological error of your predecessors, it’s not wise to use the same foundational methodology!

Maybe Alle’s team should get oh, say a half-dozen mammal results (all from different species please) before we extrapolate to all mammals. I’m just sayin’.

By: Carman

Carman — Tue, 15 Sep 2009 19:10:10 +0000

@sven dimilo: And if you read the actual article or even Science’s nontechnical version, you’ll find that is exactly what it says. Really fundamental mis-statement by the author of this article.

By: Sven DiMilo

Sven DiMilo — Mon, 14 Sep 2009 23:00:49 +0000

This doesn’t make any sense. Action potentials are passive processes–no energy is used in firing an action potential in squid or human neurons. The energy is used to pump the ions that have moved passively across the membrane back where they belong. This happens (mostly) when the neuron is “resting” between APs. There are a number of reasons why this resetting might be more efficient in mammals–smaller axon diameter and myelination, to name just two.

By: NewEnglandBob

NewEnglandBob — Mon, 14 Sep 2009 22:12:10 +0000

…squid cells were inefficient because sodium ions entering the cells neutralised the effect of potassium ions leaving. This hampered the creation of a net voltage across the cell membrane. “It’s like having the accelerator and the brake on at the same time,” says Arnd Roth

Uh Oh, PZ Myers will not like this one bit.