We used BARseq in situ sequencing to identify genes in ***1.2 million neurons*** throughout the mouse brain

We found that cortical areas with similar cell types are also interconnected. We call this “wire-by-similarity.”

biorxiv.org/content/10.110…
1/n This work was led by Xiaoyin Chen (now at Allen), with lots of fun collaborations with Stephan Fischer, Aixin Zhang, Jesse Gillis.

They all apparently anticipated the current Twitter crisis long ago by not signing up, leaving me to deliver this tweetstorm

1.5/n

Biological neural networks (BNNs) are much more energy efficient than artificial NNs. The human brain uses about 15-20W, whereas eg training a big ANN causes the lights to dim in Boston for a day or 2.

Why? 1/n

I don't usually tweet politics, but I have an idea I would like to share

We (in the US) have a serious problem: Due to gerrymandering, many congressional elections are "safe":

Such districts are decided in the Republican primary rather than the general election.

1/n Primaries are low turnout, and are dominated by the "party faithful", whose views are typically on the extreme of the party

So the winner of the R primary--and the general election-- in a safe district is often the most extreme candidate

And we are living with the result

2/n

This is a really fun question.

I think there are clearly plenty of behaviors that are so far developed in humans as to be effectively unique.

I am particularly impressed by language, which enables social cooperation and the accumulation of knowledge through generations.
1/n

https://twitter.com/zmainen/status/1463420529990381570

And we have some specializations related to dexterity (which enables tool use) and bipedality.

And our theory of mind is really sophisticated. We primates are really good at predicting others' actions; and when we started to predict our own actions, consciousness emerged
2/n

We touched on a lot of interesting subjects at the great Salon yesterday

But i would like to dig into one where i think we failed to communicate: what it means to be "close" in genetic space, and why i think it's relevant. (1/n)

@criticalneuro @neuro_data @MelMitchell1 Suppose i am trying to solve eg a prediction task, where I take inputs from a set X and try to predict Y. Maybe X is a set of images, and Y is a set of labels.

Now let's say that i try to solve it with my favorite algorithm, and fail. (2/n)

Does gene expression predict wiring in the cortex?

Here we introduce a new technique, BARseq2, to answer this question

BARseq2 looks at genes and axon projections at high throughput--thousands of single neurons and many genes per cell in parallel

doi.org/10.1101/2020.0…

1/n This is work by an amazing team: Yu-Chi Sun, Xiaoyin Chen, Stephan Fischer, @starfishlu , and Jesse Gillis

(2/n)

Should we rethink the standard science seminar, especially delivered by zoom?

I find zoom seminars much less engaging than a live delivery, both for departmental seminars and especially conferences.

Maybe there are alternatives?

1/n If we're gonna stick with the standard seminar format, maybe make it offline, edit it for clarity, and post to youtube for asynchronous viewing?

The advantage of zoom live seems minimal...maybe just a few questions at the end.

Missing the sense of shared experience

2/n

@slinnarsson proposes a radically simple strategy: "just test everyone, repeatedly. If everyone is tested there is no need to trace contacts, because they will also have been tested"

medium.com/@sten.linnarss… "The test need not be very cheap ($10 would be acceptable initially, or even possibly $100), but needs to be simple enough to be used by anyone. Ideally, a piece of paper that you spit on, with a control stripe and a stripe that changes color in minutes if you have the virus.

What is the Covid-19 endgame? How long are we going to have to live like this?

Right now, it looks like we are going to have to wait at least 12-18 months until we get a vaccine. (1/n) The devastation to the economy of social distancing practiced at the current level would be mind-boggling, dwarfing pretty much anything we've ever seen. Someone described it as an undergrad dorm discussion for econ majors (2/n)

Just found this hilarious and insightful discussion by @baconmeteor. Every slide is a gem.

@MelMitchell1 @catherineols

idlewords.com/talks/superint… @baconmeteor @MelMitchell1 @catherineols "Hopefully you see the resemblance between this vision of AI and a genie from folklore. The AI is all-powerful and gives you what you ask for, but interprets everything in a super-literal way that you end up regretting."

Connectivity of 50K single cortical neurons from a single brain obtained by MAPseq. Part 1 -- approximate locations of cell bodies. (Longwen Huang) Connectivity of 50K single cortical neurons from a single brain obtained by MAPseq. Part 2 -- some long-range projections of two of these neurons (it's hard to show all 50K at once). (Longwen Huang)