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 Basics From 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 synth...

Actin Lessons Part II: Memorabilia

Recall from the previous post, that when a neuron's axon fires repeatedly the relevant genes (in that neuron) turn on, and the synapses that are holding the short-term memory when the synapse strengthening proteins find them, become, in effect, tattooed (from Making Memories Stick by R. Douglas Fields) It appears that this 'tattooing' process involves enzymes that cause actin to change the shape of the synapse, broadening it so that more receptors can be brought into play. Much progress has been made in the past 10 years or so to understand the details of what is going on. From ScienceDaily (Jun. 14, 2004) : Neuroscientists at the Picower Center for Learning and Memory at MIT show for the first time that storage of long-term memories depends on the size and shape of synapses among neurons in the outer part of the brain, the cerebral cortex. ... When an experience or a fact is repeated enough or elicits a powerful emotional response, it shifts from short- to long-term m...

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 end...

Beta Rhythm (Music of the Mind)

Search This Blog