Cells {neuron} can have cell body, dendrites sending signals in, and axon carrying signals out.
shapes
Surroundings and connections cause unique neuron shapes. Large named neurons with special shapes include spinal cord anterior horn cells, cerebellum Purkinje cells, lateral vestibular Deiters cells, teleost Mauthner cells, primate cerebral cortex Betz cells, and primate cerebral cortex Meynert cells. Mauthner cells are for escape and startle reflexes.
size
Neurons are largest human cells, with average diameter 20 microns. Neuron volume is thousand times larger than bacterium volume.
firing rate
Neurons can output signals at maximum rate {rate saturation, neuron}, different for different neurons, up to 900 per second.
neuron genes
100 different neuron types express different gene sets. 80% of genes have repression, and the other 20% have expression at different levels, varying with cell conditions and transcriptional control. 20% of genes are for transcriptional control [Keller, 2000] [Stevens, 1998].
individuality
Neurons are different, because brains have hundreds of neurotransmitters and neurohormones, such as amino-acid derivatives, peptides, and small RNAs. Neurons have different membrane-receptor, membrane-polarization, myelination, microtubules, and gene-expression patterns. Neurons differ temporally, with different responses over different time scales. Interactions cause neurons to act differently [Grush and Churchland, 1995] [Shepherd, 1991].
Biological Sciences>Zoology>Organ>Nerve>Neuron
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Date Modified: 2022.0224