[The effect of preparations with nootropic action when used long-term on the brain bioelectrical activity in rats]. / Vliianie preparatov s nootropnoi aktivnost'iu pri ikh dlitel'nom primenenii na bioélektricheskuiu aktivnost' mozga krys.

The impact of prolonged injection of piracetam (2 months), meclophenoxate (5 months), and mexidole (5 months) on the bioelectrical activity of the sensomotor cortex and dorsal hippocamp was studied in rats who behaved freely. The injects increased and stabilized the predominant peak of EEC spectra power by the Fourier method. Discontinuation (24 hours) of piracetam failed to impair EEG spectra and bioelectrical activity. Increasing the basic effects of nootropic drugs given chronically versus acutely suggests that chronic injection enhanced their action. The drugs under study elevated the level of wakefulness and excitability of the animals, which is likely to underlie the neurophysiological mechanisms responsible for behaviour optimization under the influence of these agents.

Comparative studies on the influence of ONK (N(5-hydroxynicotinoil) glutamic acid), piracetam and meclofenoxate on the learning- and memory-impairing effect of scopolamine, clonidine, and methergoline.

The effects of the new compound N(5-hydroxynicotinoil)glutamic acid (ONK) in comparison with the well-known nootropic drugs piracetam and meclofenoxate on cognitive functions impaired by scopolamine, clonidine or methergoline were examined in albino rats and mice. The changes in learning and memory were studied by the two-way active avoidance "shuttle-box", passive avoidance "step-down" in rats and passive avoidance "step-through" in mice. The present results showed that ONK (50 mg/kg) injected intraperitoneally (i. p.), piracetam (800 mg/kg) and meclofenoxate (100 mg/kg) administered orally once daily for 5 days before training completely antagonized the scopolamine-provoked amnesia in step-through-trained mice. ONK (50 mg/kg) administered i. p., piracetam (600 mg/kg) and meclofenoxate (100 mg/kg) administered orally once daily for 5 days before training abolished the memory-impairing effect of clonidine in shuttle-box-trained rats and the amnestic effect of methergoline in step-down trained rats. The observed antiamnestic effects of the nootropic drugs studied are probably realised through their influence on cholinergic, noradrenergic and serotoninergic neurotransmission. The favourable effect of ONK on cognition might be of interest for therapeutic practice.

[Psychotropic properties of nootropic substances with a cholinergic action component in single and long-term use]. / Psikhotropnye svoistva nootropnykh veshchestv s kholinergicheskim komponentom deistviia pri odnokratnom i dlitel'nom primenenii.

Long-term administration of centrophenoxine and cleregil was found to exert on rats the antiamnestic and anxiogenic-like effects, to increase emotional reactivity and aggressiveness, to reduce motor activity and readiness to contact. The withdrawal of centrophenoxine and especially cleregil was followed by still greater enhancement of emotional reactivity and the appearance of spontaneous aggressiveness.

[Role of the GABA- and cholinergic systems in the formation of a dissociated state to an antioxidant of the 3-hydroxypyridine class]. / Rol' GAMK- i kholinergicheskikh sistem v formirovanii dissotsiirovannogo sostoianiia k antioksidantu iz klassa 3-oksipiridinov.

The experiments on rats have shown that the elaboration of conditioned drinking reflex in T-maze during administration of 2-ethyl-6-methyl-3-hydroxypyridine antioxidant with an anti-stress effect was accompanied by the development of state dependent learning. However, its formation was slower, as compared to state dependent learning in response to the known psychotropic drugs. The replacing test with the injection of bicuculline, picrotoxin, Ca valproate, Ro-15-1788, benactyzine, Cleregil, etc. during state dependent learning made it possible to establish the role of GABA and cholinergic systems in the formation of state dependent learning and in the development of disorders in emotional behavioural reactions after long-term administration and withdrawal of 3-hydroxypyridine.