Comment specific to the "...understanding the brain at the cellular level."  You can't understand the brain at that level.  All you understand is the diffusion of neuro-transmitters across the synaptic cleft, the electo-chemical interactions along and across the myelin sheath, & so on.  It's like trying to understand an automobile by looking at the alloys used in the metal and the petrochemicals used in the plastic.  

A doo run-run-run, a doo run-run