CENTRAL NERVOUS SYSTEM TUNING AND ITS IMPLICATIONS FOR NEUROPSYCHIATRY

Publisher Website
Google Scholar
Abstract
Autonomic and somatic (motor and sensory) functions are integrated at the hypo-thalamic and reticular levels. Thus increased sympathetic discharges induced ref lexly, by stimulation of the brain stem and limblc area, and by changes in internal environment enhance sympathetic hypo-thalamlc excitability, cortical desynchronlzatlon, muscle tone and arousal. This syndrome constitutes the state of ergotroplc tuning. Conversely, increased parasympathetlc activity of various origins is associated with cortical synchronization, loss in muscle tone and sleep[long dash]trophotroplc tuning. In states of ergotroplc tuning the excitability of the ergotropic system is increased and that of the trophotropic system is inhibited whereas the reverse changes occur in states of trophotropic tuning. Reciprocal relations between the ergotroplc and trophotropic systems persist in these states. Reversal phenomena occur at high degrees of ergotropic and trophotroplc tuning. A stimulus causing a sympathetic (ergotroplc) effect in the control test may produce a parasympathetic (trophotropic) effect in the state of trophotroplc tuning and corresponding data have been obtained for the reversal of parasympathetic (trophotropic) effects in the state of ergotropic tuning This phenomenon is due to the fact that a stimulus potentially able to excite both tropho- and ergotropic systems induces a response dominated by 1 or the other, depending on the state of tuning. The quantitative changes in the reactivity of the ergotropic and trophotroplc systems seen in states of ergotroplc and trophotroplc tuning result not only in alterations of autonomic and somatic reflexes, cortical potentials and similar physiological phenomena but also in complex emotional and behavioral reactions. Reversal phenomena occurring in marked states of ergotropic-trophotroplc imbalance are responsible for the conversion of a sympathetic into a parasympathetic action (and vice versa) as well as for the substitution of an arousal reaction for one of sleep in response to the same external or intracerebral stimulus. Widely different and often paradoxical reactions are based on this mechanism. Clinical states illustrating reversal phenomena are seen in narcolepsy and certain forms of neurosis in which emotional excitement elicits sleep and hypoglycemia, respectively, instead of producing arousal and hyperglycemia. The psychological and clinical significance of alterations of ergotropic and trophotroplc reactivity in states of tuning is greatly enhanced by the finding that tuning is also induced by conditional stimuli: neutral stimuli, reinforced by excitation of the ergotroplc or trophotropic systems via reflexes or by direct stimuli of appropriate central structures, may induce emotional excitement or sleep or elicit ergotropic or trophotroplc reflexes and a state of heightened ergotropic or trophotropic reactivity as well as reversal phenomena. The experiments show individual experience as the cause of exaggerated and abnormal (reversal) reactions of the ergotropic and trophotropic systems to neutral stimuli. It is suggested that neuroses are formed on this basis. There is, however, a fundamental difference between experimental and clinical neurosis, and the physiological states of ergotropic and trophotropic tuning; the neurotic state is characterized by simultaneous ergotropic and trophotropic discharges whereas reciprocal relations between the ergotropic and trophotropic systems prevail in physiological states of tuning. The significance of states of ergotroplc -trophotropic imbalance and the theory of tuning for some problems of neuropsychiatry is discussed.