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The integrative activity of the brain is particularly related to the telencephalic level of CNS. Drugs affecting learning and memory usually interfere with the reticular or limbic system, and are either stimulants or sedatives. In contrast, Piracetam (U C B 6215) is an atoxic compound which, up to dosages such as g/kg, does not interfere with autonomic functions, general behavior, level of wakefulness, the limbic system, etc. Yet, in dosages such as mg/kg it improves several learning and memory abilities, protects against experimental amnesic agents, facilitates EEG recovery after severe hypoxia and also facilitates interhemispheric transfer (transcallosal evoked potential and learned behavior). Discussion is made on the basis of the particular neuropharmacology as well as on the available biochemical and human clinical correlations to emphasize the selectivity of this compound on telencephalic integrative mechanisms. Piracetam is presented as the first-comer of a new psychotropic class for which the termnootropic is proposed.

Rats were trained on a continuously reinforced bar-press response for water reward. Seven days later they were retested for retention, with or without pretest injection of the nootropic drug, piracetam. Drug-treated animals had significantly shorter response latencies than saline-treated animals. The results are interpreted as a facilitation of retrieval processes after forgetting. The experiment was extended under extinction conditions and it was found that after three sessions there was a tendency to facilitate extinction when response latency is used as the extinction index. The clinical interest of a drug which facilitates the retrieval aspect of the memory process without impairing extinction is discussed.

Nootropics were proposed as a class of psychoactive drugs selectively improving efficiency of higher telencephalic, integrative activities (Giurgea, 1972). The main features of the nootropic pharmacology are: (1) enhancement of learning acquisition (water-maze, Y-maze, “drinking”-test, spinal fixation active avoidance) and resistance to impairing agents (hypoxia, ECS, chemicals, sensory deprivation, age); (2) facilitation of interhemispheric transfer of informations (callosal evoked potentials, visual discriminative learning); (3) enhanced resistance to brain “aggressions” such as nitrogen hypoxia, experimental high-altitude or drugs overdosing; (4) increased tonic, cortico - subcoitical “control” (LGB-induced nystagmus inhibited and spinal fixation facilitated by Piracetam); (5) absence of usual pharmacological effects such as sedation, stimulation, autonomic modulations or toxicity, even in very high dosages. All experimental features are thoroughly correlated with human pharmacoclinical and therapeutic data supporting the view that nootropic activity is based on a functional telencephalic selectivity. Geropsychiatric implications are discussed relative to (1) geropsychiatric self-perpetuating “vicious” circle (Lehmann, 1975); (2) cerebral hypoxia; (3) reduced, “dys-adaptive” plasticity with aging; (4) CNS-inhibitory reduced efficiency and sensory deprivation induced deficits.

The above motto expresses the choice of the subject matter for this chapter. The authors are not going to discuss rejuvenating cures, nor elixirs or drugs claimed to be effective accordingly. Nor — other than incidentally — will the important scientific achievements in the knowledge of tissue, cellular, and metabolic age-related changes or possible drugs interactions at that level be dealt with. Those aspects of ageing are beyond the scope of this chapter and also beyond that of the authors’ own competence.

Der Ausdruck Reaktivitat wird fur das Zentralnervensystem in dem Sinn verwendet, das er die Fahigkeit des Systems darstellt, durch Stimulation rezeptiver Organe aktiviert zu werden. Plastizitat ist dann die Fahigkeit, die Reaktivitat als Ergebnis fruherer Aktivierungen oder, allgemein ausgedruckt, fruherer Erfahrungen zu andern (Konorsky, 1967).

In an operant conditioning situation a visual stimulus, presented about 40 times per trial, was used in a control group of Wistar rats, to learn to avoid an electric shock.

Les experiences discutees ont porte sur le rOle de la motivation — sous la forme d'un renforcement —dans l'etablissement de reponses conditionnees instrumentales chez le rat. Les resultats obtenus sur un groupe experimental et un groupe de contrOle comprenant chacun 7 animaux, montrent que la contiguite temporelle de 2 stimuli neutres (son-lumiere) permet aux animaux d'etablir entre ceux-ci une relation fonctionnelle sans intervention d'un facteur specifique de motivation.

Resume Chez le lapineveille, non curariseet non anesthesie, une reponseelectrocorticale specifique aux barbituriques, au meprobamate et au chlordiazepoxide est decrite sous le nom de phenomene d'amplification du rythme rapide de base. L'attention est attiree sur le fait que ce phenomene constitue l'effet initial induit sur l'EEG par les doses hypnotiques et meˆme non hypnotiques (doses moderees) des psychotropesetudies. Les hypnotiques non barbituriques, la thalidomide et les autres tranquillisants en usage n'entrainent pas le phenomene decrit. La signification de ce phenomene est discutee.