Axon diameter relates to synaptic bouton size: structural properties define computationally different types of cortical connections in primates

Brain Struct Funct. 2017 Apr;222(3):1169-1177. doi: 10.1007/s00429-016-1266-1. Epub 2016 Jul 2.

Abstract

Neural connections are implemented by axons of different diameters, whose spectrum increases depending on species and areas. Axon diameter determines conduction velocity and is proportional to the size of the cell body of origin. We describe that in motor, callosal connections of the monkey thick axons distribute larger boutons than thin axons, suggesting that faster axons also release more neurotransmitter at their termination, probably activating more powerfully their targets.

Keywords: Axonal phenotype; Computational neuroanatomy; Corpus callosum; Cortex; Motor; Synapses.

MeSH terms

  • Animals
  • Axons / physiology*
  • Biotin / analogs & derivatives
  • Biotin / metabolism
  • Cerebral Cortex / cytology*
  • Cerebral Cortex / physiology
  • Computer Graphics
  • Corpus Callosum / cytology
  • Corpus Callosum / physiology*
  • Dextrans / metabolism
  • Macaca fascicularis
  • Male
  • Models, Neurological
  • Nerve Net / physiology*
  • Presynaptic Terminals / classification*

Substances

  • Dextrans
  • biotinylated dextran amine
  • Biotin