Morphometric changes of prefrontal cortex neurons in white laboratory rats under conditions of the eating of the protein-deficiency food after acute sound stress

Morphometric changes in neurons in the prefrontal cortex of white laboratory rats under conditions of protein deficiency in food after acute sound exposure remain unexplored. Purpose: morphometry of neurons in the prefrontal cortex of sexually mature white laboratory rats after acute sound exposure in conditions of low-protein food. The experiments were carried out on 64 sexually mature nonlinear white laboratory male rats weighing 180-230 g (8 - intact, 56 - experimental). After a single continuous sound exposure with an intensity of 120 dB for 120 seconds, 56 rats were divided into 2 groups: with balanced food (control - 28) and low-protein food (main food - 28); with two subgroups in each: stress-resistant (12) and stress-nonresistant (16). The animals were removed from the experiment on days 10, 20, 30 and 40 after the start of the experiment. Samples of prefrontal cortex preparations were examined histologically, immunohistochemically, and morphometrically. After acute sound exposure, the indicators of the area of the cytoplasm, nucleus and nucleoli of neurons in the prefrontal cortex of white laboratory rats change. Chromatolysis of Nissl's substance occurs in most neurons of the II-III layers of neurons. During all periods of observation, morphometric changes were most pronounced in stress-nonresistant animals of the main group of experiments, especially in the first 10 days after exposure. Chromatolysis in neurons of the prefrontal cortex persists until the end of the experiment, which indicates incomplete repair of the intracellular protein-synthesizing functional system after acute sound stress. Thus, an acute sound effected causes morphometric changes in neurons and initiates chromatolysis of Nissl's substance in them in layers II-III of the cortex of the prefrontal region of the brain of white laboratory rats. Chromatolysis in animals with low-protein food after acute sound exposure in the II-III layers of the prefrontal cortex is irreversible, remains statistically significantly high and can be regarded as a manifestation of decompensation of structural changes in animals under conditions of protein deficiency in food.