Nanobiology Notes

Perkinjes and Granules and Schwanns, oh my...

It's tempting to oversimplify things. Like neurons. It would be nice if there were one type of neuron, and all you needed to know about how neurons work could be clearly labelled on a diagram of that one type of neuron. Well, nature LOVES to specialize. So, before getting deeper into how neurons work, I thought it would be good to take a step back and get some vocabulary in place...The BasicsFrom University of Washington's 'Neuroscience for kids':Neurons come in many different shapes and sizes. Some of the smallest neurons have cell bodies that are only 4 microns wide. Some of the biggest neurons have cell bodies that are 100 microns wide. Neurons are similar to other cells in the body because: Neurons are surrounded by a cell membrane. Neurons have a nucleus that contains genes. Neurons contain cytoplasm, mitochondria and other "organelles". Neurons carry out basic cellular processes such as protein synthesis and energy production. However, neurons diff…

It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so.

-- Mark Twain

So far, most of the posts in this blog have been focused on building a 'bottom-up' understanding of how the brain works - from how DNA works up to how individual neurons work. Lots of good science to base all of this stuff on. It is difficult to go further 'up the stack' in this way, however. How do neurons work together to do useful things? How are small-scale networks of neurons structured and how do the neurons interact in order for us to do simple things like rhythmically tap a finger?

Are we there yet?
Every decade or two the scientific community gets wildly optimistic that we will be able to fully understand how cognition works and be able to replicate the process in some non-biological system. It's been named many things over the years - cybernetics, artificial intelligence, computational intelligence, cognitive computing (see http://en.wikipedia.org/wiki/Artificial_intelligence for a nice overview). And yet, with all of the money tha…

Synaptic Vesicles - Message in a bottle

Previous blog entries have covered what Neurotransmitters are, and how synaptic receptors use these molecules as triggers for complex actions once they have crossed the synapse. This blog entry explores the other side of the synaptic cleft, where the neurotransmitters are stored and released.

Nature has developed some amazing machinery to make synapses fire quickly. Relying on the cell nucleus to generate the molecules that act as neurotransmitters when they are needed would be far too slow to achieve the kind of speed required to power thought. Instead, these molecules are made ahead of time, before they are needed, and are kept bottled up in spherical containers called 'vesicles', waiting for the instant that they need to be released. The picture that is evolving on how synapses actually manage this feat is quite fascinating. And, once again, that super cool molecule called 'clathrin' plays a major role...

From http://www.hhmi.org/research/investigators/sudhof.h…

Beta Rhythm (Music of the Mind)

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