The behavior of animal and man is based on the processing of data which takes place within groups of interconnected nerve cells. Such populations of neurons take the form of relatively diffuse networks in primitive animals, e.g., certain jellyfishes, whereas in more highly organized animals they are concentrated in particular structures (brain, ganglia, ventral or spinal cord) . The results of neuronal data processing are electrical events conducted to particular muscle groups which then contract according to a central program and produce spatially and temporally coordinated patterns of movement, that is, behavior (Fig. 1). The “commands” for the activation of such motor programs can originate from the central nervous system (CNS) itself, and they can be influenced by the endocrine system. The execution of a “motor command” - the behavioral response - may be controlled by sensory systems. “Commands” can also be elicited by particular signals of the environment, following appropriate processing of the sensory input (Fig. 1). In the latter case, too, it is important to note that the efficacy of an environmental stimulus - and with it its signal character - depends in considerable measure upon internal conditions; we refer to drive or motivation.
KeywordsElectrical Brain Stimulation Interconnected Nerve Cell Female Frog Pigeon Breed Cricket Frog
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