List of animals by number of neurons

The second list shows the number of neurons in the structure that has been found to be representative of animal intelligence.

[3] Neurons are the cells that transmit information in an animal's nervous system so that it can sense stimuli from its environment and behave accordingly.

The number of neurons and their relative abundance in different parts of the brain is a determinant of neural function and, consequently, of behavior.

[1] This accounts for variation in the number of neurons in the rest of the brain, for which no link to intelligence has been established.

The following table gives information on the number of neurons estimated to be in the sensory-associative structure: the cerebral cortex (aka pallium) for mammals, the dorsal ventricular ridge ("DVR" or "hypopallium") of the pallium for birds, and the corpora pedunculata ("mushroom bodies") for insects.