AIMS
The study evaluates the dependence of p53 protein expression on the appearance of dark neurons (DN) in the hippocampus in rats during experimental modeling of septoplasty.
MATERIALS AND METHODS
Septoplasty simulation was carried out on 15 sexually mature male Wistar rats. We studied histological sections of the hippocampus stained with Nissl toluidine blue and antibodies to the p53 protein.
RESULTS
In the CA1 subfield, the number of p53-positive neurons significantly increased on the 2nd, 4th (p<0.001) and 6th days (p<0.05). In the dynamics, the peak of the growth of p53 protein expression in the cytoplasm of CA1 and CA2 neurons fell on the 2—4th day after the operation, and on the 6th day the number of these neurons decreased (p<0.001). In the cytoplasm of CA3 neurons at all periods after surgery, an increase in the expression of the p53 protein was noted as compared to the control group. In the CA1 pyramidal layer, the number of DN decreased on the 6th day (p<0.001). In CA2, after 2 days, a minimum of DN was noted, compared with the 4th day (p<0.001). In CA3, on the 4th day, there was a peak in DN, compared with the rest of the days (p<0.001). A positive strong association was found at all periods of assessment and in all subfields of the hippocampus between an increase in the number of dark and p53-positive neurons.
CONCLUSIONS
The appearance of dark and p53-positive neurons in the hippocampal formation in rats after simulating septoplasty are typical responses of nervous tissue to stress. It is obvious that the expression of the p53 protein is associated with the basophilia of the cytoplasm of neurons, their morpho-functional state. Presumably, the p53 protein can trigger not only the activation of damaged neurons in the hippocampus, but also play a neuroprotective role. Upcoming studies should determine the role of the p53 protein in the further fate of damaged neurons in the pyramidal layer and differentiate the mechanisms of its expression.