Studies of the Central Respiratory Mechanisms. A new project has been started, i.e., to trace the descending respiratory pathway from the hypothalamus to the rostral pons. The pneumotaxic mechanism will be isolated, except its connection with the hypothalamus. The neurons in this mechanism will be recorded by microelectrode, and their activity will be studied when the hypothalamus is heated locally by a thermode. Mechanism of Antipyretic Action of Acetylsalicylate. Attempts are made to determine the mechanism of the antipyretic action of sodium aspirin by producing hyperthermia with micro-injections of a smaller amount of pyrogen into the hypothalamus on one side, and small amount of sodium aspirin into the other side. In this way, it is possible to determine if aspirin reduced pyrogen-induced febrile reaction via a competitive mechanism. Site of Miotic Action of Morphine. A model has been successfully found that the anesthetized animals have relatively large pupils, which are sensitive to morphine. Microelectrode is placed in the Nucleus Edinger Wesphal and other nuclei along the pathway of the light reflex to determine which of these neural structures are responsible in producing miosis following morphine administration.