Extracellular recording uses larger electrodes that can be used in the brains of living animals. This method cannot usually resolve the tiny electrical signals generated by individual synaptic connections, but it can pick up action potentials generated by individual neurons, as well as field potentials generated by synchronous synaptic activity in large groups of neurons.
The brain manages its complex task by orchestrating functional subsystems, which can be categorized in a number of ways: anatomically, chemically, and functionally.
t a higher level yet is the primary motor cortex, a strip of tissue located at the posterior edge of the frontal lobe. The primary motor cortex sends projections to the subcortical motor areas, but also sends a massive projection directly to the spinal cord, via the so-called pyramidal tract. This direct corticospinal projection allows for precise voluntary control of the fine details of movements. Other "secondary" motor-related brain areas do not project directly to the spinal cord, but instead act on the cortical or subcortical primary motor areas.