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Exploring the brain with drugs

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The nature and distribution of drag-induced or dragmodified responses, in health and in disease or experimental approximations of similarly disturbed function, have been investigated. From the results it appears that: 1. A sensitive substrate of drag action is the neurohumorally-determined synaptic equilibrium, which is transiently disturbed by transmission and distorted by drugs. These act through their ability to mimic or alter the duration of action of the cholinergic, excitatory, or adrenergic and serotoninergic inhibitory neurohumors. 2. Cerebral synaptic responsiveness to drugs isqualitatively identical at various cerebral sites sampled, including the cortex, subcortex and brainstem. This, therefore, is a general characteristic which, however, exhibits markedquantitative differences. 3. Because of such differential thresholds, drugs can cause disruption of normal relations or equilibrium between parts of the brain, as with LSD, or, if appropriately used, can act to promote restoration of equilibrium, as with tranquilizers and antidepressants. 4. A concept of cerebral homeostasis can be equated with mental health and its disturbance with psychosis, which is then regarded as a failure of cerebral integration. Clinical yardsticks for measuring degrees of functional integration are proposed, which make use of subclinical doses of drugs to challenge cerebral homeostasis in quantified lever-pressing and perceptual aberration-tracking situations. Exploration of the brain with drugs allows also exploration of the mind, for which it is the substrate. Drugs may be used to increase understanding of cerebral function in health and disease and to assess functional disintegration, as in brain damage, aging, mental retardation and mental disturbance. Proposed clinical yardsticks based on this could be used for diagnosis, evaluation of therapy, screening populations for individuals in need of preventive or prophylactic care, and in evaluation of new drugs.

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Read at the First Meeting of the Collegium Internationale Activitas Nervosae Superioris, Madrid, September 9, 1966.

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Mabrazzi, A.S. Exploring the brain with drugs. Conditional Reflex 3, 181–188 (1968). https://doi.org/10.1007/BF03000129

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  • Conditional Reflex
  • Biological Psychiatry
  • Conditioned Approach
  • Disturbed Function
  • Conditioned Behavior