Number of synapses in cerebral cortex

Range ~1.5×10^14 synapses
Organism Human Homo sapiens
Reference Drachman D (2005). "Do we have brain to spare?".Neurology 64 (12): 2004–5.doi:10.1212/01.WNL.0000166914.38327.BB. p.2004 left column top paragraphPubMed ID15985565
Primary Source Pakkenberg B, Pelvig D, Marner L, et al. Aging and the human neocortex. Exp Gerontol 2003 38: 95–99.PubMed ID12543266
Method Stereologic studies
Comments p.2004 left column top paragraph:"Within the liter and a half of human brain, stereologic studies estimate that there are approximately 20 billion neocortical neurons, with an average of 7,000 synaptic connections each (primary source). The cerebral cortex has about 0.15 quadrillion synapses—or about a trillion synapses per cubic centimeter of cortex."
Entered by Uri M
ID 112056