"Your idea might not work, unlike these other proposals using existing technology. So, lower score for approach."

(Gets it to work, submits proposal to use it...)

"You need to add Dr. X as co-PI. He's good at using existing tech on this question. He just got lots of $$$ for it actually"

The quote is from the founding documents of the BRAIN Initiative. Its support has allowed voltage imaging to attain performance levels predicted to be impossible not so long ago.

So thx to NINDS, NIMH, and NIH for investing in technology development!

obamawhitehouse.archives.gov/node/300741

That, and voltage indicators residing in a thin layer of membrane, is what makes voltage imaging inherently more challenging than calcium imaging, even when the voltage indicators provide more signal per event per molecule than calcium indicators (and they do)

The traces also illustrate well why you *must* image at 400 Hz or faster. The AP-induced ASAP4e transient only lasts for one frame (≤2.5 ms). If you image at 30 Hz (33 ms integration) then you'll average down the response to noise.

So calcium transients mask real spike patterns, and may give a misleading, or at least over-persistent, impression of how sub-second sensations or motions are encoded.

They also performed calcium imaging with GCaMP6f. This gives a nice comparison of how calcium and voltage differ in kinetics.

Essentially the entire voltage trace above (4 sec) would fit into one medium-sized calcium transient below.

The FOV is 0.38mm x 0.15mm, containing 19 labelled neurons. ASAP4e spikes had dF/F of 40% and SNR of 5.5 – 7.4.

The results show nicely that voltage recordings with ASAP4e aren't difficult. You just have to image at ≥400 frames per second.

Actually they don't want to pay very much for them afterwards either

Somewhere in there: thinking, reading, analyzing, advising, listening, presenting, writing papers.

Might be easier for others. Choosing to specialize in technology development is selecting difficulty mode for grant-writing... people want the tools but they don't want to pay for them in advance.

No problem!

Would you mind posting a link to the article; I couldn't find it. Thanks!

I addressed this as well in the original thread. Thanks Christophe for linking to it

Thus the arbitrary 95% standard and how it is applied leads to contradictory conclusions, making scientists seem to hapless and clueless. So it harms public understanding and scientific support to insist on painting results in black or white rather than how they actually are: shades of gray.

And this is not just an academic exercise. How many times do you read in the news there is no association between risk factor X and outcome Y, only to read the opposite a few months later? These inconsistencies are often due to these Type 2 errors of declaring no difference when there was one.

It's more informative, accurate, and comprehensive than our current rules of saying yes or no when the answer is almost always different degrees of maybe. It would do justice to the concept of statistics, which is the supposed to be the science of quantifying degrees of certainty.

Then one can calmly and rationally consider whether that result provides some support for a hypothesis, together with what is mechanistically likely.

Again this would be for the 95% of non-clinical experiments that aren't addressing a hypothesis with treatment-chaning or financial implications.