User:Elenam13/sandbox

From the Greek: neuro and pilos, meaning felt. . The term most likely originated in the late 19th century. In neuroanatomy, a neuropil, which is sometimes referred to as a neuropile, is a region between neuronal cell bodies in the gray matter of the brain and blood-brain barrier (i.e. the central nervous system). It consists of a dense tangle of axon terminals, dendrites and glial cell processes. It is where synaptic connections are formed between branches of axons and dendrites.

White matter, which is mostly composed of axons and glial cells, is generally not considered to be a part of the neuropil.

Examples
Neuropil has been found in the following regions: outer neocortex layer, barrel cortex, inner plexiform layer and outer plexiform layer, glomerulus (plural glomeruli). These are all found in humans but many species have counterparts similar to our own regions of neuropil. However, the degree of similarity depends upon the composition of neuropil being compared. The concentrations of neuropil within certain regions are important to determine because simply using the proportions of the different postsynaptic elements does not verify the necessary, conclusive evidence. Comparing the concentrations can determine whether or not proportions of different postsynaptic elements contacted a particular axonal pathway. Relative concentrations could signify a reflection of different postsynaptic elements in the neuropil or show that axons sought out and formed synapses only with specific postsynaptic elements.

Recent
The neuropil provides a proxy measure of total connectivity within a local region because it is comprised mostly of dendrites, axons, and synapses.