Nanobiology Notes

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…

Neurotransmitters - molecular messages

You often hear about neurotransmitters in the news and in science magazines in a kind of off-hand way that assumes everyone must surely know what these things are. But, um, what are they, exactly?

From Sandra Ackerman's book "Discovering the Brain": To be recognized as a neurotransmitter, a chemical compound must satisfy six conditions: It must be

synthesized in the neuron, stored there, released in sufficient quantity to bring about some physical effect; when administered experimentally, the compound must demonstrate the same effect that it brings about in living tissue; there must be receptor sites specific to this compound on the postsynaptic membrane, as well as a means for shutting off its effect, either by causing its swift decomposition or by reuptake, absorbing it back into the cell.

OK, well, what about hormones? They're chemical messengers too - how are hormones different from neurotransmitters? A hormone, by definition, is a compound produced by an endocrine…

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…

Beta Rhythm (Music of the Mind)

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