Saturday, October 26, 2013

Optogenetics - Switching on Neurons with Light

Brain structure and learning research is on an steep progress curve these days as imaging and signal processing is better understood. It is particularly cool to me that an important leap ahead has been achieved via the light receptors of algae found in the pond scum, Chlamydomonas. This simple algae uses light sensitive proteins to move (phototaxis) and feed via photosynthesis. So how did basic research on pond scum in 2002 get applied to brain research in the fall of 2013? Scientific curiosity and collaboration

An NSF-funded team of brain researchers at Stanford University, Karl Deisseroth, Edward Boyden, and Feng Zhang were looking for a chemical "switch" to turn neurons on/off. They used light sensitive algal proteins to turn on the electrochemical signaling of the neurons. These results also drove the development of tools to:

  • Turn off target neurons by manipulating light-sensing proteins
  • Deliver light via laser to target neurons in the brain
  • Insert light-sensitive proteins into different types of neurons to study their functions
  • Study of how gene expression in the brain may influence neurochemical signaling and how changes in key neuronal genes may influence learning and memory
So the next time you feel like pond scum, realize that even it has its strengths! Go science!

Tuesday, October 8, 2013


As you can imagine, I like science movies, science fiction, and other assorted real and imagined technology (even Steampunk).

So when I heard from more than one person that the new movie, Gravity, with George Clooney and Sandra Bullock, got a 97% approval rating on Rotten Tomatoes, (has it ever happened before?) I made plans to see it this weekend.

Mark Uhran, a 28-year NASA veteran with the International Space Station, said it was extremely realistic. I worked at Johnson Space Center in Houston, TX for thirteen years and the movie trailer made my stomach lurch. I can hardly wait to see the movie. To avoid spoliers, let's comment next week when a lot of us have seen it. Go Science!

Friday, October 4, 2013

Scientists studying the songs of songbirds have found it to be mostly a learned behavior subject to environmental influences like rearing and food availability. In fact, researchers from the Max Planck Institute for Ornithology in Seewiesen compared song and brain structure of parents and offspring in zebra finches that were raised with genetic or foster parents. They also varied the amount of food during breeding. They found that song and underlying brain structure didn't appear to be as affected by genetics as by strong environmental factors.

These results related to a human behavioral biology question (i.e., which aspects of behavior are learned compared to those expressed by genetic predisposition). It's known that human personality and behavior are much less set by genetic background. Environmental factors shape brain and behavior by so-called epigenetic effects. In fact, hormones play an big role and can have long lasting effects. 

Research with zebra finch breeding pairs (where half of the hatchlings were raised by their genetic parents, and the other half were raised by their foster parents) showed this too. At 100 days when the male offspring were grown, the researchers recorded their songs. The results showed that genetic heritability was low for most song characteristics, except the number of song syllables and maximum frequency. The rearing environment and song of the foster father mainly predicted the unique syllables of the sons' songs and was dependent on food availability. 

So keep feeding the birds in your backyard and providing a healthy environment. Songbirds will be happy and singing. Go Science!