Signal the state of muscle contraction. Intensity of stimulation is often coded by the firing rate at which neurons respond. Changes in distribution of receptor types, number and modification of receptors occurs in evolution. These changes in receptor are reflected at all levels of the nervous system. Expansion of some sensory system and contraction of others.
Spinal cord has grey matter and white matter.
Both types are arranged in a striped pattern on the bill and dominate the central nervous system. Star-nosed mole and eastern mole Dorsal and ventral horns and axon tracts. Two separate types of information 1. The N system synapses ipsilaterally in substantia gelitinosa , crosses the spinal cord and ascend the contralateral spinal cord to synapse in the thalamus. This is the spinothalamic tract.