Express-methods based on functional and morphological features of the genus Spirostomum have been applied for estimation of the effect produced by chemical toxicants, γ-radiation, electromagnetic emission, and homeopathic drugs on the aquatic environment. The experiments have shown that Sp. ambiguum is a very useful indicator for the bioassay of low-intensity physical and chemical pollution in the aquatic environment.

Mnemotropic effect has been revealed in the action of Derinat, a biologically active compound of natural origin, on the formation of conditioned reflexes of active and passive avoidance. Derinat accelerates the elaboration of conditioned reflexes. This effect manifests itself already at initial stages of the elaboration, which resembles the effect produced by nootropics.

Mnemotropic effect of Piyavit®-a biologically active compound of natural origin—was studied on conditioned avoidance in rats. Morphological changes in neocortex and hippocampus (neuron-glia complex and brain capillaries) were significant and oppositely oriented. We assume that the improvement of rats’ memory under the Piyavitis associated with metabolic changes in the nervous tissues.

Stable dose-independent behavioral modification in the infusorium Spirostomum ambiguum immediately after the exposure to γ-radiation in a broad dosage range has been shown in model experiments. Negative effect is observed already at a dose of 0.01 Gy and is inherited through several generations of spirostoma. Decreased motor activity is accompanied by morphological pathology, the manifestation of which is also dose-independent in a broad range of low doses. The possibility of express evaluation of changes in the motor activity of protozoa for the biotesting of radioactive contamination of the environment, as well as the prognostic character of this study, is under discussion.

Derinat is a drug consisting of sturgeon milt containing DNA sodium salt. We found a positive effect of derinat on acquisition of active avoidance response and restoration of this response after its functional disturbances induced by impairments of cause-effect or spatial relationships. We suppose that derinat has nootropic properties.

Поиск фармакологических веществ, оказывающих нейропротективное действие на память и когнитивные функции человека при различных патологиях ЦНС, и анализ механизмов их действия составляют важное направление современной нейробиологии. В течение ряда лет проводятся исследования по анализу закономерности регуляции процессов памяти биологически активными соединениями природного происхождения. Одной из особенностей этих исследований является использование соединений с макромолекулярными компонентами (ДНК, РНК и белки), определяющими спектр механизмов действия. Данный подход позволяет прогнозировать новые мнемотропные свойства у ранее изученных биологически активных соединений [1]. Проведение этих исследований составляет необходимое условие для расширения возможности дальнейшего использования в медицинской практике природных биологически активных соединений. В последнее время в клинической практике успешно используется препарат деринат, в частности в психиатрии при терапии последствий нейроинфекционных и черепно-мозговых травм [2]. Деринат — это натриевая соль ДНК, деполимеризованная ультразвуком до частиц с молекулярной массой 270—500 кД в 0,1%-м растворе хлорида натрия. Благодаря оптимальной молекулярной массе деринат проникает в клетки пиноцитозом, т.е. без разрушения их мембран. Препарат получают из молок осетровых и лососевых рыб. Так как одним из ключевых показателей состояния психики пациентов психиатрических клиник служит память, то представляло интерес исследовать влияние дерината на условно-рефлекторную память у крыс в норме и при ее функциональных нарушениях. Материалы и методы

The effects of the DNA-containing biologically active compound polidan on conditioning in rats were investigated. Passive avoidance conditioning was used as a model of memory. Polidan at a dose of 10−10 M had a positive effect on memory.

The aim of this work was to study the influence of different regimens of polydan administration on the structural and metabolic state of neurons of rat hippocampus and neocortex. The animals of experimental groups were administered 75 mg/kg of polydan intraperitoneally once or 5 times. Animals of control groups received similar injections of sodium chloride isotonic solution. Light microscopic study of hippocampus and somatosensory area of neocortex demonstrated 4 types of neurons that could be distinguished according to the degree of their staining with methylene blue. Polydan administration resulted in redistribution of relative proportions of neurons of these types and in increase of the number of nucleoli in these cells, thus indicating an activation of synthetic processes. Quantitative ultrastructural analysis of ribosomes in the cytoplasm of neurons of hippocampal area CA3 and neocortical layer V has confirmed the activation of protein synthesis. Intensification of synthetic processes in neurons was further supported by the analysis of mitochondrial cristae and matrix. It is suggested that synthesis activation in brain neurons is a structural and functional basis for the mnemotropic effect of polydan.

Electron microscopy and morphometry of neurons in layer V of the somatosensory area in the neocortex and CA3 field in the dorsal hippocampus showed that single and 5-fold intraperitoneal injection of Polidan was followed by ultrastructural and metabolic changes in neurons reflecting activation of protein synthesis. The number of free ribosomes decreased; the number of polysomes and count of ribosomes in polysomes and tubules of the granular endoplasmic reticulum increased. Study of mitochondria and neuropil showed that Polidan activates synthetic processes in the neocortex and hippocampus. It should be emphasized that single treatment with Polidan led to functional activation of synthetic processes, while 5-fold injection of Polidan was followed by hyperactivation of synthetic processes and depletion of ultrastructures in the neocortex and hippocampus.

Light microscopy revealed four types of neurons differing by staining intensity and size in each of the pyramidal neuron populations in the dorsal hippocampal fields and layer V of the neocortical somatosensory area and in granular cells of the dentate fascia and stellate cells of layer II of the same cerebrocortical area in rats. Treatment with Polydan according to different protocols led to redistribution of these types of cells, which attests to stimulation of synthetic processes in these brain areas, rather than to similar sequence of the involvement of different brain areas in this process. Polydan promoted the increase in the mean number of nucleoli in the nuclei of neurons of all types, the degree of this increase being different for each type. It seems that morphological signs (staining intensity and number and size of nucleoli in the nuclei) reflect certain functional states of the neurons in the homogeneous populations. Presumably, various factors can stimulate transition of neurons from one morphofunctional status into another.

New experimental data on the mnemotropic (nootropic) properties of the well-known drug polidan (a DNA derivative) are summarized. The results obtained by histological techniques showed changes in the brain structure, indicating protein synthesis activation under the action of polidan. These results confirm prognostic function of the concept of evolutionary-molecular basis of memory.

The effect of piracetam on the development of a two-link system of feed-procuring conditioned reflexes was studied in rats with probability reinforcement. The experiments showed that piracetam improves both the current learning process and the memory track (previous experience) reproduction. In addition, the drug decreases the role of the probabilic character of reinforcement, thus facilitating the synthesis of two reflexes in a united functional complex.