ABSTRACT
Living organisms are intricate systems having thousands of ongoing processes interacting to maintain even the most basic life functions (i.e., energy production and protein synthesis). As the behavioral requirements of the organism increase, the complexity of the nervous system must also increase to initiate and coordinate a large variety of movements. For example, the
clione,
which has been studied extensively, has approximately 5000 neurons organized in five pairs of central ganglia. All the functional requirements of the
clione
can be regulated by this small nervous system, and electrical stimulation applied to specific groups of neurons can evoke stereotypical responses. Although humans possess a much larger repertoire of movements and therefore have significantly more complex nervous systems, levels of functional stereotypical organization remain within the central (brain and spinal cord) and peripheral nervous systems. Knowledge of the neural mechanisms underlying normal movements is an invaluable asset when designing a neuroprosthetic device because it enables one to tap into the neural circuitry residing at different levels to influence downstream events.
