11 August 2012

Tenth International Congress for Neuroethology, Day 5

After a fairly late night on the cruise, plus the usual last day attrition, made for a slightly subdued day for many attendees. But not for me.

The last plenary talk of the conference was Toshiya Matsushima, who was discussing decision making in chicks. He was one of those speakers who is very quiet, almost soft-spoken, but who has a way of pulling you into his world. And he still threw in the occasional joke, with a low-key, but still funny, delivery.

He briefly mentioned how grateful he was for the support of the Society following the tsunami and subsequent Fukishima disaster. Then, he described a series of experiments looking at how chicks decide how to feed. They can train chicks to peck for food, and do various manipulations where they reward less food immediately, or more food after a brief delay. He again invoked the Heiligenberg rule (“Use the champion animal”) to say that chicks were champion feeders. There is high mortality among chicks, and they have to put on weight very quickly in the first few days after hatching.

He also recorded from the chicks’ nucleus accumbens, and found that there were some neurons that responded to the amount of food that was expected (the learned response), the expected delay, and the actual reward. He compared these to three judges who had to decide on a single sentence (the behaviour).

Then, he described what happens when you do surgery on this region of the brain. There are a couple of different effects. For one, the chicks become impulsive. The chicks also become more persistent, and will continue pecking even when they get no reward for much longer than normal chicks.

He ended his talk comparing scientific research to, of all things, bonsai trees. But it was a lovely metaphor. A bonsai is not a forest, but a single miniature tree. You cannot create a bonsai quickly; it takes decades. it may even be passed from generation to generation. But through this human art, you catch a glimpse of nature.

I did not get a relaxing coffee break, as I was working to make sure the speakers for the nociception symposium were all good to go. (Neuroethologists use video than most, and video is still exceptionally picky in presentation software.) Such is the life of a symposium co-organizer.

Dan Tracey was, um, our representative for the “evil four.” He's been working on nociception in Drosophila for about ten years. Although the title of the symposium was “Nociceptors in the real world,” Tracey said he was really talking about pain. He noted that people can study responses to light in both humans and flies, and both get to call it vision. It’s not that only the human researchers get to study “vision”; the fly researchers do not have to say they study “photoreception.”

With the genetic tools at his disposal, he and his lab has been making excellent progress on what genes and neurons are responsible for nociception in flies. For instance, he has been able to put channel rhodopsin in flies, and cause the maggots to do their characteristic thrashing behaviour of nociception by shining light on them. “This was the coolest day ever, because it worked.”

But he never loses sight of the behaviour. There are a lot of great ecological research questions about the relation of the maggot’s nociceptors with parasitoid flies that attack them. Tracey showed the maggots can actually shake off the parasitoid attackers, prompting him to say, “When you see a fruit fly, I want you to think of Sigourney Weaver,” in reference to her famous Aliens roles.

Robyn Crook is workings with a favourite of this blog, cephalopods. She was able to record neurons that act very much like nociceptors, which nobody had ever done in cephs before (as discussed here a couple of years ago).

Her take on nociception was to relate it not to short term stimuli, but in the context of long term injuries. Squid, which she works with, are often found in the wild missing the tips of their tentacles, for instance. She was able to show that the squid do change their defensive behaviours when given these mild injuries. They tested these with sticks with hairs on the end. “Behaviour has complex equipment. Duct tape is very important,” she deadpanned.

Co-organizer Ewan St. John Smith talked about his work on naked mole rats, a good chunk of which was published in Nature last year. Naked mole rats have a small number of common mammalian sensory neurons called C-fibers. And it is just the naked animals, not other haired mole rats that have this reduction.

Not only that, they are insensitive to acids. Somewhat surprisingly, all the ion channels of acid detection were still in the mole rat neurons, but there was a sort of genetic “shunt” that prevented the neurons from generating action potentials when exposed to acid. All of these seems to be related to the mole rats living almost perpetually underground in high carbon dioxide laden dens.

The last speaker was Victoria Braithwaite, who was talking about fish nociception. (You can find my review of her book, Do Fish Feel Pain? here.) She summarized some of her work on the nociceptive sensory neurons from about 10 years ago. Her more recent research is geared to showing not just that fish have nociception, but that they use that information in a way that is suggestive of pain.

One of the big arguments that she has faced from critics is that fish cannot feel pain because they have no neocortex. She argues that the relevant brain structures for processing pain in humans are the amygdala and the hippocampus, and fish do have equivalent structures in their brains.

L to R: Ewan, Dan, Robyn, and Victoria

All our speakers had lots of questions at the end of the session, and we were all able to continue the discussion over lunch.

I was incredibly pleased. I thought the symposium achieved everything we had set out to do. The talks were a great mix, and none felt out of place at a neuroethology meeting.

I had to leave immediately after lunch, and could not stay for the last contributed talk session. I was particularly bummed to miss the talk by my co-organizer Ashley, who was one of the very last speakers for the entire conference.

I got to the airport in what I thought was plenty of time, but my self check-in failed. So I went to stand in a line-up. A line-up that lasted over an hour. When I finally got to the front, I learned that my flight had been delayed. Again. And my connecting flight in Dallas was the last one of the day. I was almost certainly stuck in the Dallas airport for the night.

Externally, I laughed. Because you have to, as they say. Internally? “Crap crap crap crap.” I got one tiny little ray of hope: Dallas flights were also being delayed, so I might make it. But I only gave theft about a 10% chance. And I dropped that to 5% when the flight missed its delayed departure time by about 45 minutes.

But I made an excellent start on this blog post.

I got into Dallas about 10:00 pm, and the last flight back to McAllen was long gone. And I was indeed stuck in the airport overnight, left to wonder what god of travel I had so annoyed that have m last three trips delayed so much that I arrive at my destination on the wrong day. Fortunately, a computer can now make longe delays much more tolerable than they used to be.

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