Neuroscience News - Neuroscience Research Neuroscience Labs Neuroscience... Mind Uploading: Brain Facts. What's the scale of things here?
The following lengths (from Posner p. 305) give approximate sizes for structures in the nervous system: 0.001 mm: synapses (tip of a connection between neurons) 0.1 mm: neurons (brain cell) 1 mm: local circuits (small networks of cells) 10 mm: maps (spatially organized topographic maps) 100 mm: systems (e.g., the visual system) 1000 mm: the central nervous system (including spinal cord) How many things are we talking about? Short answer: a LOT. Neurological Control - Neurotransmitters. Neurotransmitter Molecules Neurotransmitters can be broadly split into two groups – the ‘classical’, small molecule neurotransmitters and the relatively larger neuropeptide neurotransmitters.
Within the category of small molecule neurotransmitters, the biogenic amines (dopamine, noradrenaline, serotonin and histamine) are often referred to as a discrete group because of their similarity in terms of their chemical properties. Click on the links in the table above to read more about some of the important neurotransmitters.