Anatomy of the cerebellum numerous neuron in the brain (roughly 70% of all neurons in the brain and spinal cord, combined). Golgi cells provide inhibitory feedback to granule cells, forming a synapse with them and projecting an axon into the molecular layer. The local field potentials of the neocortex and cerebellum oscillate coherently at (6–40 Hz) in awake behaving animals. These appear to be under the control of output from the cerebral cortex. This output would be mediated by a pathway from layer 5/6 neurons in the neocortex through that project either to the pons or the inferior olive. If through the pons this
Medulla (hair) Medulla (hair) The medulla is the innermost layer of the hair shaft. This nearly invisible layer is the most soft and fragile, and serves as the pith or marrow of the hair. Scientists are still uncertain about the exact role of the medulla, but they speculate that it is primarily an extension that is more prominent in depigmented (grey or white) hair Human hair is unique in that its medullary index (the fraction of the hair shaft's diameter that the medulla occupies) is very small: generally less than 1/3. Other species will have much larger ratios, usually at least 1/2.