[The respiratory reactions to thyroliberin action on the ventral surface of the medulla oblongata].

Applications of the TRH to the brain stem ventral surface of anesthetized rats increased the lung ventilation and essential changes in the breathing pattern. At the same time, electrical activity of inspiratory neurons was enhanced and that of expiratory neurons reduced (the ambiguous nucleus area). The data obtained suggest a major role of ventrolateral medulla in realization of the TRH respiratory effects.

[Chemosensitive structures of the medulla oblongata participate in blood pressure regulation and belong to APUD-system].

It was shown in 25 experiments on anesthetized spontaneously breathing and immobilized artificially ventilated cats that the cooling of the intermediate chemosensitive area of the ventral surface of medulla oblongata to 20-22 degrees C is followed by depressor reaction that is more pronounced after preliminary occlusion of the sinocarotid and vagus nerves. Two types of apudocytes were revealed in this brain area with the use of the histochemical and immunohistochemical techniques. The first type cells are typically nervous and contain noradrenaline.