âWe are the laggard partner in this co-evolution.â âShe said that Newry's success is not through external help but through the energy of the people that âcaptured the imagination of the whole of Ireland and even cajoled the laggard politicians.ââ
One type of neuron called the Purkinje cell, found in the cerebellum, may have as many as one hundred thousand synapses.How big is a synapse? [ii]Synapses are very small. This narrow gap of extracellular space is approximately 20-40 nanometers (nm) wide. For an idea of scale, one inch is about 25.4 million nm long. The thickness of a single sheet of paper is about 100,000 nm.[iii]How many synapses are in the human brain?[iv][v]Current studies estimate that the average adult male human brain contains approximately 86 billion neurons.
The brain is divided into the right and left hemisphere, and the two halves are connected by the corpus callosum. This bundle of nerve tissue contains over 200 million axons (nerve fibers that carry electrical impulses from neuronsâ cell bodies) by rough estimate. This neural tissue facilitates communication between the two sides of the brain. The corpus callosum is the largest collection of white matter within the brain, and it has a high myelin content. Myelin is a fatty, protective coating around nerves that facilitates quicker transmission of information. White matter should not be confused with gray matter.