<P> The number of neurons in the brain varies dramatically from species to species . The adult human brain contains about 85 - 86 billion neurons , of which 16.3 billion are in the cerebral cortex and 69 billion in the cerebellum . By contrast , the nematode worm Caenorhabditis elegans has just 302 neurons , making it an ideal experimental subject as scientists have been able to map all of the organism 's neurons . The fruit fly Drosophila melanogaster , a common subject in biological experiments , has around 100,000 neurons and exhibits many complex behaviors . Many properties of neurons , from the type of neurotransmitters used to ion channel composition , are maintained across species , allowing scientists to study processes occurring in more complex organisms in much simpler experimental systems . </P>
<P> The number of neurons in the brain varies dramatically from species to species . The adult human brain contains about 85 - 86 billion neurons , of which 16.3 billion are in the cerebral cortex and 69 billion in the cerebellum . By contrast , the nematode worm Caenorhabditis elegans has just 302 neurons , making it an ideal experimental subject as scientists have been able to map all of the organism 's neurons . The fruit fly Drosophila melanogaster , a common subject in biological experiments , has around 100,000 neurons and exhibits many complex behaviors . Many properties of neurons , from the type of neurotransmitters used to ion channel composition , are maintained across species , allowing scientists to study processes occurring in more complex organisms in much simpler experimental systems . </P>
where do you find neurons in the brain
where do you find neurons in the brain
cerebellum cerebral cortex
cerebellum cerebral cortex