Biomedical subjects

K A Nikol'skaya

Publications and source records attributed to K A Nikol'skaya.

6 recordsLinked to original sources

PubMed2005

Psychoemotional manifestations in hippocampectomized rats.

The effects of lesioning of the dorsal hippocampus on the psychoemotional state of Wistar rats were studied. Hippocampal lesions did not affect the learning process, but affected mainly the pattern of psychoemotional manifestations in all animals regardless of the typology of higher nervous activity. All animals showed reductions in the extremes of types of passive and active stress reactions. Individual effects depended on the behavioral phenotypes of the animals. Hippocampal lesions in rapidly learning rats (10%) led to sharp decreases in irritability (active/passive = 0.35/0.5 instead of 1.0/0.4), while passive-defensive manifestations were not altered. In slowly learning animals (30%), hippocampal lesions were not accompanied by qualitative changes in the patterns of psychoemotional manifestations, while non-learning rats (60%) showed decreases in passive and increases in active manifestations (active/passive = 0.45/1.4 instead of 0.3/1.9). It is suggested that the hippocampus is involved in producing psychoemotional reactions, individual patterns of which depend on the morphofunctional characteristics of the system responsible for organizing the psychoemotional state.

Animals↗

PubMed2004

Active control and its stress effects.

The effects of 5-fold injections of normal saline were studied in Wistar rats in two conditioned reflex situations: defense and alimentary. Intact animals developed conditioned pain avoidance reflex in repeated tail-flick test after 60 presentations over 3 days. Two injections of normal saline were sufficient for the formation of a stable negative stress status in experimental rats, which manifested by a drastic increase in tactile sensitivity persisting for 5 days after discontinuation of injections. Only 15% experimental rats vs. 40% intact animals developed the food-procuring response in a multialternative maze. Presumably, repeated injections of normal saline should be regarded as a potent negative stress factor modulating animals behavior, and these signs should be taken into consideration, when interpreting the effects observed in pharmacological investigations.

Animals↗

PubMedDate not supplied

Cytochemical parameters of synaptic neurons in rats with different abilities to learn a food-procuring habit.

The characteristics of protein metabolism associated with cognitive activity were studied in neurons of layers III and IV of the sensorimotor cortex of rats, using two groups of Wistar rats. Regardless of the success of learning, information loading was most clearly reflected in the associative neurons of layer III. In rats with poor learning ability, these neurons showed increases in nuclear and cytoplasmic size, along with increases in protein concentration and content. The clearest changes in efferent neurons (layer V) were increases in the area and protein content, occurring only in the cytoplasm. In rats with good learning outcomes, all cytochemical parameters responded to information loading with decreases in layer III and increases in layer V protein contents and concentrations, affecting both the cytoplasm and nucleus. The question of whether the vector of changes in neuronal protein metabolism in response to information loading can be regarded as a measure of the individual features of higher nervous activity is discussed, as is the question of whether the magnitude of these changes is a measure of the complexity of a cognitive task.

Animals↗

PubMedDate not supplied

Morphochemical features of sensorimotor cortex and neostriatum neurons in rats with different levels of alcohol preference.

This paper reports interferometric studies of the contents and concentrations of proteins in the cellular structures of neurons of the sensorimotor cortex (layers III, V) and in the region of the caudate nucleus of the neostriatum (Golgi type II cells) in Wistar rats with high, intermediate, and low levels of ethanol preference. The greatest differences between groups of animals in terms of cell size and protein metabolism were seen in the cortex. Along with measures correlating with initial ethanol preference (cell body size, nucleus size, and cytoplasm size of cortical neurons, cytoplasmic protein content, etc.), a number of measures were found to show statistically significant differences which did not correlate with preference (nuclear protein contents and concentrations in cortical neurons of layers III and V). These data may suggest the existence of another significant measure responsible for the difference between the groups and, possibly, more closely correlated with the analytical-synthetic functions of the central nervous system.

Alcohol Drinking↗

PubMedDate not supplied

Retention of memory traces in rats subjected to 10 minutes of clinical death.

Studies of the effects of 10-min clinical death in mongrel rats, induced by complete circulatory arrest, on the mechanisms of memory, showed that the content of already formed memories ("what to do?"), i.e., the structure of a food-procuring habit, motivational activity, and the level of organization of behavior, was completely retained 12 days after resuscitation regardless of how many traces were formed before the experimental procedure. Transient changes seen after clinical death mainly affected the process of performing the habit ("how to do it?"): there was a decrease in the ability to work, along with degradation of performance parameters such as readiness, mobilization activity, and the stability with which memory traces were performed. The rate of recovery of these aspects depended on the initial level of conditioned reflex activity in the rats: the higher this level, the more rapidly the performance parameters returned to the baseline level. It is suggested that these disturbances in the process of reproduction were non-specific in nature and could be due to the post-operative hyperexcitability of the animals.

Animals↗

PubMedDate not supplied

[Comparative characteristics of psychoemotional patterns in Albino and Wistar rats].

Analysis of psychoemotional behavioral component in Albino and Wistar rats during solving a cognitive task showed that intra-population differences were determined by the relationship between passive and active forms of unconditioned reactions. Quick-learning rats from both populations were characterized by the dominance of active forms of psychoemotional reactions over the course of training. The learning process in slow-learning rats was accompanied mainly by passive emotional manifestations, whereas active reactions dominated at the stage of habit realization. Passive forms of manifestations prevailed over active forms over the course of training in both Albino and Wistar rats which failed to solve the task. The interpopulational psychoemotional differences were quantitative and depended only on the learning styles. Wistar strain was characterized by a decreased percent of animals which were able to solve a cognitive task (40% versus 80% in Albino rats), affective flatness and decreased tolerance to information loadings.

Animals↗