Man may be accidentally trapped in confined atmosphere in which there is a limited availability of oxygen. The effects of various ambient conditions on survival in confined space were previously studied. In these studies the hypoxic collapse could not be attributed to a specific malfunction of one of the three vital systems: the cardio-circulatory, respiratory or cerebral. We presently evaluated the importance of cerebral function in immature pigs placed in confined space with selegiline, a pharmacological brain protection agent. The immature pigs consumed the oxygen in the chamber until hypoxic collapse, while we measured: blood pressure, oxygen consumption, CO₂ output, inspired O₂ and CO₂, minute ventilation, ECG, EEG, body temperature, and PO₂ PCO₂ and pH in arterial and mixed venous blood. The selegiline treatment to the experimental group was injected into the pulmonary artery at normoxia, while the control group was injected with the same volume of saline. The results did not indicate any beneficial effect for this pharmacological treatment.