I’m not the lucky owner of an Ipad, but I did enter every possible raffle, lottery and prize quiz at this conference to increase my chances of finally getting one. Until then my notepad made of paper will do just fine. You might think that I am thoroughly outdated, but then you would actually be mistaken. You see, tablets are much much older than pen and paper. Around the 8th century BC, the old greeks used a wax tablet and a stylus to take notes on, whereas paper came around in the 2nd century AD.
The tabula (how the Greeks called their wax tablet) was an inexpensive way to take notes and wipe it clean by just heating up the wax, creating a tabula rasa. Neuroscientists think of something very different when they use those words. At least when I hear them I think about experience-dependent and -independent mechanisms that sculpt the developing brain.
This morning, David Fitzpatrick gave a very nice talk on just that. How much of the features encoded in our visual cortex require the circuitry to be sculpted by visual experience? Or is it mostly a fixed developmental program that runs independently of light hitting the retina?
He started with acknowledging the work of Hubel and Wiesel, who while having fun in the lab did so much groundwork on the workings of the visual cortex that afterwards nothing much was left to be discovered. Thanks guys, real great work!
Fortunately, I’m exaggerating and many questions remain. One of the questions that Fitzpatrick asked is:
Do cells in the primary visual cortex require visual input in order to become selectively responsive to certain orientations and directions?
We know from rearing animals in complete darkness that orientation selectivity develops independently of visual input. Direction selectivity on the other hand does not, since it is almost absent in dark-reared and immature ferrets and cats. This seems to be different however in rodents, Nathalie Rochefort showed very recently that mice as soon as they open their eyes have cells properly tuned to direction, albeit initially there is a bias to dorsal and anterior directions. An explanantion for this is that already at the retina there are direction selective ganglion cells, that have shown to project to the thalamus. I believe that in ferrets this has not yet been studied.
Beautiful data collected just weeks ago in the Max-Planck institute in Florida showed how cells in immature ferrets become rapidly direction selective if you train the animals by repeatedly showing them a drifting grating in a certain direction. They followed this in the time course of many hours by chronic Ca2+ imaging using the genetically decoded indicator GCaMP3. It was astonishing to watch the cells bounce back and forth between preferred direction to see them eventually organize into columns.
We’ve come to another interesting difference between mice and cats. Mice’s response properties such as orientation -, direction selectivity and ocular dominance is topographically scattered in a salt and pepper fashion, whereas cats have a very nice columnar organization. I remember distinctly when I entered the field of visual plasticity how disappointed I was to hear this. David made me realize that it just raises an extremely interesting question: What is the difference in their circuitry that gives rise to either a salt and pepper organization or columns? I always thought it was, among other things, a scaling problem. Fitzpatrick proposed that there could be differences in the respective weights of inhibitory and excitatory inputs and that different operations could play a role in determining the tuning of the cells. That sounds to me like there is still a lot for us left to discover. Hubel and Wiesel eat your heart out!
I was still tweaking my poster at 3 in the morning on a Wednesday and thought: I will not be jetlagged. In the plane (which was packed with neuroscientists) over here I slept for a solid six hours! I felt refreshed and ready to start my day at 15:00 local time. So I’m still a bit jetlagged but just not adjusted to any existing time zone nearby.
At our arrival we were waiting for immigration for over an hour. Then there was another cue for the transport to the city center. If you’re still traveling, do yourself a favor and book it in advance. Or take the bus outside at platform 2E, it’s cheap (6 euros in exact change), runs frequently and is much less popular than a taxi or a coach.
We checked in at the Helix hotel which is groovy, no seriously it is Groovy baby! Feels like walking into an Austin Powers movie. Also, the room is bigger than my Amsterdam apartment! I’m loving this trip already.
First stop was Kramerbooks & Afterwords, where I felt like a kid in a candy store. After buying the new Murakami, a comic about Feynman and Jonah Lehrer’s book How we decide, I became a bit overenthusiastic and I had to stop myself from buying 100 facts about pandas. The dinner at Kramerbooks was also really good, although expensive. And I can recommend that you try the DC brau there. A belgian-like beer brewed here in Washington, it’s called the citizen.
If you’re still traveling, have a safe trip!
Most people I spoke to about the SfN neuroblogging are surprised that only one or two bloggers were chosen per theme. And I must say that I fully agree. Given that it is such an enormous event, I couldn’t possibly tell you about all the interesting things there. So I’m hoping that this doesn’t stop anyone from tweeting and posting about the meeting (just add the #sfn11 hashtag if you’re using twitter).
Here are some alternative blogs and a tweetlist to keep in mind:
Neuroskeptic (smart and funny, what else you need?)
Brain windows (a great colourful blog about optical tools to study the brain)
SfN tweeters (just reply to Noah Gray if you want to be added to that list)
If I failed to mention your blog, just reply to the post so I can add you to the blogroll…
Every now and then grad students ask each other, so what’s your backup plan? If your science career fails, whatcha you gonna do?
My plan B is to start up a bookstore/internet cafe/restaurant, all in one. Turns out Washington has such a wonderful place!
Kramerbooks & Afterwords (www.kramers.com)
After the mandatory visit to the white house, I’m surely going to pick up a book and cup of coffee at Kramers. But what else is worthwhile in Washington?
So here’s a question to all Washingtonians:
Where should we go when we’re having a few hours of free time during the SfN conference?
Welcome to my page, where I will be blogging about all the interesting events, lectures and posters at SfN that I come across. My main interests are neural plasticity, twophoton imaging and you’ll find that I get easily excited about inhibition.
I hope you have a good time reading and please feel free to leave comments.
p.s. It’ll be my first time at SfN as well as my first visit to the US and I’m really looking forward to it (can’t believe the meeting is so soon already). But first lots and lots of preparations!