The method of determining the number of excited efferent cardiac fibers in the vagus nerve of a cat

Objective: Developing method of determination the number of excited efferent cardiac fibers in the cervical region of the vagus nerve of a cat by estimating the area of the glow in the high-frequency electromagnetic field inside the nerve. Materials and methods: The observations were carried out on cats in conditions of superficial (27 cats) or deep anesthesia (13 cats out of 27) and irritation of the vagus nerve with electrical impulses (14 cats out of 27). The right vagus nerve on cat’s neck was allocated and cut at the level of the lower edge of thyroid cartilage. The central end was inserted into a glass tube. Before the cut end in the transverse plane, a scanner from the unit, which creates a high-frequency electromagnetic field was installed. The glow from the scanner were recorded by a video camera through the microscope. At the same time, the ECG was recorded. Based on the ECG signal, for the processing we took the centers of glow related to the heart rhythm. The results were processed in the "STATISTIKA 6.0" program. Results: In superficial anesthesia, the number of excitable efferent fibers was 350 or 70.0% of the available ones. In case of deep anesthesia, 193 or 38.6% accordingly. In case of nerve stimulation above the transection site all available efferent fibers have been excitable. Conclusions: Results of this work suggest a way to identify and determine the number of excitable efferent cardiac fibers in the vagus nerve and their localization on the cross section of the central end of the nerve from the area of luminescence in high-frequency electric field.