Influences of an acoustic signal with ultrasound components on the acquisition of a defensive conditioned reflex in Wistar rats.

The effects of short (90 sec) exposures to a complex acoustic signal with ultrasound components on the acquisition of a defensive conditioned two-way avoidance reflex using an electric shock as the unconditioned stimulus in a shuttle box were studied in female Wistar rats. This stimulus induced audiogenic convulsions of different severities in 59% of the animals. A scale for assessing the ability of rats to acquire the conditioned two-way avoidance reflex was developed. Presentation of the complex acoustic signal was found to be a powerful stressor for Wistar rats, preventing the acquisition of the reflex in the early stages (four and six days) after presentation. This effect was independent of the presence and severity of audiogenic convulsions in the rats during presentation of the acoustic signal. On repeat training nine days after the acoustic signal (with the first session after four days), acquisition of the reflex was hindered (as compared with controls not presented with the acoustic signal). However, on repeat training at later time points (1.5 months after the complex acoustic signal, with the first session after six days), the rats rapidly achieved the learning criterion (10 correct avoidance responses in a row). On the other hand, if the acoustic signal was presented at different times (immediately or at three or 45 days) after the first training session, the animals' ability to acquire the reflex on repeat training was not impaired at either the early or late periods after exposure to the stressor. These results suggest that the complex acoustic signal impairs short-term memory (the process of acquisition of the conditioned two-way avoidance reflex at the early post-presentation time point) but has no effect on long-term memory or consolidation of the memory trace.

[Influence of acoustic signal with ultrasonic components on the development of defensive conditioned reflex in Wistar rats].

Short-term (90 s) effects of the complex acoustic signal (CAS) with ultrasonic components on the development of defensive conditioned reflex of two-way active avoidance in a shuttle-box were studied in female Wistar rats. The learning ability of rats was measured on a scale designed in our laboratory. It was shown that CAS stimulation triggered an audiogenic seizure of different strength in 59% of animals. The CAS was extremely stressful for Wistar rats: it prevented the active avoidance learning in early terms after its application (the first training session in 4 or 6 days). This effect did not depend on the presence or intensity of audiogenic seizures during CAS. In the second training session in 9 days (the first session was in 4 days), learning was impaired as compared to control without CAS. However, during repeated training procedure 1.5 months after the CAS (the first session in 6 days), rats rapidly reached the criterion of learning (10 consecutive avoidance reactions). On the other hand, if the CAS was presented with different time lags (immediately, in 3 or in 45 days) after the first training session, the ability of animals to learn during the second session was not impaired both in early and late terms after exposure to the stressor. The results suggest that exposure to CAS prevents development of short-term memory but does not affect consolidation process and long-term memory.

The effects of Mexidol on the acquisition of food-related conditioned reflexes and synaptic ultrastructure in field CA1 of the rat hippocampus after single acoustic stimuli with ultrasonic components.

The effects of a complex acoustic signal with ultrasonic components on the ultrastructure of synapses field CA1 of the rat hippocampus were studied in conditions of two-week courses of the wide-spectrum antioxidant Mexidol (compared with an untreated group); the effects of complex acoustic signals on the dynamics of acquisition of a food-related conditioned reflex using a standard stimulus (a tone) and on the acquisition of a trace conditioned reflex to estimating time intervals were also studied, in the same groups of rats. Controls consisted of unstressed rats treated and not treated with Mexidol. Ultrastructural analysis of the redistribution of vesicles in the synaptic terminals of hippocampal field CA1 showed that synaptic transmission was impaired when assessed one day after exposure to the complex acoustic signal. Mexidol prevented impairment of synaptic transmission. The complex acoustic signal had negative effects on conditioned reflex activity in rats and Mexidol had normalizing actions on the acquisition of conditioned reflexes in stressed rats. These results lead to the conclusion that the antioxidant Mexidol can be applied to the prophylaxis of the impairments in CNS cognitive functions frequently seen in stress.

[The effects of Mexidol on food conditioning and synaptic fine structure of hippocampal field CA1 in rats exposed to a single acoustic stimulation with ultrasonic components]. / Vliianie meksidola na vyrabotku pishchevykh uslovnykh refleksov i ul'trastrukturu sinapsov polia CA1 gippokampa krys posle odnokratnogo vozdeistviia akusticheskogo signala s ul'trazvukovymi sostavliaiushchimi.

The effect of exposure of rats to a complex acoustic signal with ultrasonic components on line structure of synapses of the CA1 field of the hippocampus was studied during a course treatment (two weeks) with broad-spectrum antioxidant Mexidol. Under the same conditions, the time course of food conditioning by a conditioned tone stimulus and acquisition of trace conditioned reflex (time interval counting) were studied in the same rat group. Rats non-exposed to stress against the background of Mexidol and without Mexidol treatment served as control. Analysis of fine structure of the vesicle redistribution in CA1 synapses revealed a reduction of the efficacy of synaptic transmission a day after the exposure to the complex acoustic stimulus. We found a negative effect of the complex acoustic stimulus on conditioning by tone and acquisition of time-counting trace reflex by rats. This effect was shown to be normalized by the course Mexidol treatment. The results suggests the expediency of Mexidol application for prevention of cognitive disorders, which are frequent under stress-inducing conditions.

[Complex evaluation of neuropsychological cognitive and emotional personality disorders in multiple sclerosis]. / Kompleksnyi podkhod k otsenke kognitivnoi i émotsional'no-lichnostnoi sfer u bol'nykh rasseiannym sklerozom.

UNLABELLED: 30 patients with definite MS and mild or moderate disability were tested with expended neuropsychological, psychiatric, psychological, neurological, neurophysiological, MRI methods. The aim of the study was to analyse the role of cognitive, emotional and personal peculiarities in MS clinical picture and its influence on patients adaptation and quality of life. It was found, that patients with MS had high level of personal anxiety, emotional ways of coping and low scores in constructive reasoning, narrowing of motivation sphere. Neuropsychological test performance revealed low level in activation, regulatory and operation brain processing connected with dysfunction in relations of profound structures with frontal brain and dysfunction of temporal-occipital zones of right hemisphere and also with connections between hemispheres. CONCLUSION: All changes had relationship with brain MRI abnormalities and neurophysiological characteristics.

Development of neuronal ganglion xenografts from gastropoda in rat brain.

Survival of neuronal ganglia from newborn snail (Helix aspera L.) in the brain of adult rats was studied. Snail ganglion survived in the brain of warm-blooded animals for 6 months without inducing immune conflict. At early stages (5 days) after transplantation, xenografts increased in size and were several times larger than native ganglia from 10-day-old snails, thereafter (on days 28 and 180) they became smaller still surpassing the sizes of ganglia from snail of the corresponding age. Rapid enlargement of the xenograft was due to cell reactive processes in the ganglion. Deep penetration of large vessels from xenografts to rat brain was observed.

Comparison of reactive processes in the rat brain elicited by xenotransplantation of nervous tissues of chicken or pulmonate snail.

It is known that a histocompatibility system is not developed to the same extent in lower invertebrates as in vertebrate animals. We assumed that the xenografts from the newborn invertebrate nervous system would not exert destructive effects on the brain of the vertebrate recipient even without immunosuppressive therapy. In search of brain xenografts (XG) capable to survive in the brain of a recipient without intensive immunosuppression, we transplanted ganglia of terrestrial snails into the rat brain. We compared effects of transplantation of the XG taken from anterior brain of the 18-day embryo chicken (XGC) and from ganglia of a newborn terrestrial pulmonate snail (Helix aspersa L., XGSn). Part of the XGSn were stained by vital fluorescent dyes Bisbenzimid or Fast Blue before grafting. The XGSn were implanted into the neocortex parenchyma in each hemisphere. Rat brains with the XGC were examined 5 days after, and brains with the XGSn - 5 and 28 days after the transplantation. Nonstained sections with the XGSn labeled with fluorescent dyes prior to transplantation were investigated in fluorescent microscope and stained later with tionin and cresyl-violet. Quantitative videoimage analysis of lymphocyte aggregations, reactive gliosis, morphology of the XG areas, and implantation trace was performed. It was found that the XGSn transplantation did not elicit in the rat brain an intensive immunological conflict 5 and 28 days after transplantation. In contrast, the XGC rapidly elicited a strong immune response resulting in massive obliterations in the rat brain and were rejected in 5 days. Labeled snail glia and vessels were observed in the stained XGSn 28 days after transplantation by fluorescence imaging. Putative snail vessels grew into the rat brain from the place of snail tissue transplantation serving the humoral integration of the XG and the host brain. Migration of molluscan glial cells was observed in the brain of recipients.

[Spectrum of neuropsychological changes in multiple sclerosis]. / Spektr neiropsikhologicheskikh izmenenii pri rasseiannom skleroze.

Early disability of patients with multiple sclerosis at the able-bodied age is often caused by both a neurological disorder and the difficulties of their social and psychological adaptation that is aggravated significantly by higher cortical dysfunctions and by behavioral problems. The paper presents the results of the dynamic neuropsychological observation of 124 patients with multiple sclerosis and of their first degree relatives. Even at the early stage of the disease there were some cognitive disorders as worse transitent verbal, semantic, visual memory active attention and slower sensomotor reactions; difficulties in conceptual mentality. The cognitive functions, the activity of the disease, an actual psychological state, depression for example, and the expression of brain atrophy and the localization of the foci are bound by the certain way. The personality traits of patients and their close relatives testified a possible psychosomatic nature of this disease.

[The content of interleukin-1 beta in the blood serum of patients with systemic lupus erythematosus and rheumatoid arthritis]. / Issledovanie soderzhaniia interleikina-1 beta v syvorotke krovi bol'nykh sistemnoi krasnoi volchankoi i revmatoidnym artritom.

The enzyme immunoassay determined serum levels of interleukin-1 beta (IL-1 beta) in 35 patients with systemic lupus erythematosus (SLE) and 18 rheumatoid arthritis (RA) patients. In high activity of both SLE and RA as well as in the presence of fever, anemia, marked skin vasculitis IL-1 beta rose high, still higher levels being reported in patients with erosive joints compared to those in RA patients with initial stage of RA. Lower IL-1 beta content often marked nephropathy in both the diseases. Corticosteroids and cytostatics resulted in IL-1 beta fall which was also established in 9 SLE and 3 RA patients in parallel with inhibition of the process activity.

[The level of the tumor necrosis factor in the blood serum of patients with systemic lupus erythematosus and rheumatoid arthritis]. / Uroven' faktora nekroza opukholi v syvorotke krovi bol'nykh sistemnoi krasnoi volchankoi i revmatoidnym artritom.

The contents of tumor necrosis factor alpha (TNF alpha) was measured by enzyme immunoassay in the serum from 43 healthy donors against 49 patients with systemic lupus erythematosus (SLE) or rheumatoid arthritis (RA). In all the donors the cytokine did not reach 50 pg/ml, in SLE and RA running actively TNF alpha levels got elevated in the absence of previous long-term immunocorrection. Under the treatment effect blood levels of the cytokine fell in inhibition of the autoimmune process. Resistant to therapy patients with active rheumatic process kept for a long period on steroids exhibited TNF alpha concentrations less than 50 pg/ml. Low activity of the process and no need in corrective therapy were attended by normal TNF alpha content. The findings urge further efforts in the search for new approaches to SLE and RA treatment.