Progressive increases in the worldwide number of cases of brain diseases accompanied by cognitive impairments continually reinforce the relevance of the need for further investigation and pharmacotherapy of this type of neuromental pathology, particularly as this problem has great significance, not only in the medical sphere, but also in the social. This explains the currently extensive interest of investigators of different specialties in studies of the role of the hippocampus (HPO) in the genesis of these disorders and the possibility that nootropic substances have influences on it.

Lesions to the dorsal hippocampus and removal of the epiphysis had differently-directed effects on behavior in rats in conditions of a conflict situation and on the temporal dynamics of forced swimming. The combination of both operative procedures resulted in weakening of the behavioral changes typical of hippocampus deficiency. It is suggested that the anti-stress properties of epiphyseal factors may be mediated by changes in the functional state of the hippocampus.

Длительное (30 дней) введение крысам нейролептиков галоперидола и рисперидона приводило к повышению уровня аутоантител к дофамину у крыс в среднем в 5,5 раз (p < 0,01) независимо от использованной дозы препаратов (0,1 и 0,5 мг/кг). Одновременно вещества в обеих дозах сопоставимо увеличивали содержание аутоантител к дофаминовым рецепторам 1-типа в среднем в 40 раз (p < 0,01). Титр плазменных антител к дофаминовым рецепторам 2-типа также возрастал, в наибольшей степени при использовании низкой дозы рисперидона (0,1 мг/кг).

Bilateral electrolytic lesioning of the striatum led to a delay in the acquisition of a conditioned reflex to time, along with an anxiogenic effect and disturbances to the normal relationship between the level of anxiety and chronometric ability. These changes progressed with increases in the size of the destruction zone in the striatum. Combined surgery consisting of lesions to the striatum and hippocampus, like hippocampectomy alone, completely eliminated the ability to count time regardless of the size of brain lesions. The anxiogenic effect was greater in animaLs with combined procedures. Thus, the striatum and hippocampus are involved to different extents in the mechanism of internal time counting. The two structures function synergistically.

Electrolytic destruction of the dorsal hippocampus prevented the acquisition of a conditioned reflex to time regardless of the volume of brain damage. A similar effect was obtained in rats with combined lesions consisting of damage to the suprachiasmatic nuclei of the hypothalamus and hippocampectomy (in the same animal). Denucleation (without hippocampectomy), conversely, accelerated the acquisition of this type of time-related behavior. Lesions to the hippocampus had no effect on the recovery of the conditioned reflex to time when this had been fixed before surgery in denucleated rats. It is proposed that the suprachiasmatic nuclei and hippocampus have simultaneous roles in organizing the endogenous counting of short time periods.