Primate Brain Synapse Counts - Comparing Humans & Chimps

[Dr Wu]

Hi

According to Wikipedia, there are approximately 140 trillion synapses in an average human adult brain. So I would be interested to know how this number compares with the number of synapses in a chimp's brain.

Many thanks.

 

[berkeman]

Hi

According to Wikipedia, there are approximately 140 trillion synapses in an average human adult brain. So I would be interested to know how this number compares with the number of synapses in a chimp's brain.

Many thanks.

I would think Google would be able to help you figure this out (that's what I would use). Have you tried some Google search terms to see where they lead you?

 

[Dr Wu]

Yes, I did try Google and came upon some deeply technical material on the subject of primate brains, but found nothing (as yet) that answers my simple question. Finally I returned to Wikipedia, which is where I got the above figure for human beings. But here too, as is evident via the link below, the Wiki info concerning synapse distribution in other primates is non-existent. . . although good on cats and fruit flies! I will continue my search online. It just strikes me as faintly odd that information of this kind isn't readily available. Chimps, bonobos, gorillas etc are our nearest cousins, after all. (Perhaps I should try and email the neuroscientist, David Eagleman!)

https://en.wikipedia.org/wiki/List_of_animals_by_number_of_neurons

 

[Laroxe]

I don't know if this helps, its mainly about development but includes some estimates. The idea of the number of synapses doesn't really make sense, there isn't any fixed number, plasticity in the brain means it is constantly remodeling its connections. We have a bigger brain, with more neurons which interact differently. The fact that the brain doesn't really operate as single neurons interacting, everything the brain does involves complex networks involving most areas, there are differences in the way these networks operate in humans and chimps. Its also worth remembering that the synapse is not the only mechanism that influences the target cells action potential.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5110243/