Pach clamp experiments on pyramidal dendrites support a model where a single pyramidal cell is equivalent to a 2-layer AI-style neural net.
“So, we now think of the neuron in terms of a two-layer model,” Mel said. “The first layer of processing occurs within separate dendritic branches. Each branch independently adds up the inputs to that branch, and then applies its own local thresholding non-linearity.”
“In the second layer of processing,” Mel added, “the results from all the different branches are added together linearly at the cell body, where they help to determine the cell’s overall firing rate.”
(note: the News & Reviews calls this a 3-layer neural net model. The third layer woud be provided by the apical tuft; Polsky et al do in fact mention this possible extension)
Nelson Spruston and William L Kath. News & Views: Dendritic arithmetic.
Nature Neuroscience 7, 567 – 569 (2004).
Alon Polsky, Bartlett W Mel & Jackie Schiller. Computational subunits in thin dendrites of pyramidal cells. Nature Neuroscience 7, 621 – 627 (2004)