Excitatory effect on skeletal muscles. Control sodium ion channels and produces depolarizations. Inhibitory effect on the muscle fibers of the heart. Controls potassium ion channesl and produces hyperpolarizations. Also plays role in learning and remembering and controls the onset of REM sleep.
Muscle fibers contain only nicotinic receptors.
The CNS contains mostly muscarinic receptors, but also some nicotinic receptors. The Monoamines There are four drugs considered monoamines because their molecular structure is similar. Because these are so similar, some drugs will affect each of these receptors to a degree. Within the mammalian central nervous system, there is evidence that the monoamine transmitters are found in pathways essential for sensory and motor performance as well as for higher brain functions. What is more, most of the cells containing these transmitters are clustered together in discrete regions of the brain.