Cerebral Vascular Responses and Metabolic Ramifications Associated With +GZ-Induced Loss of Consciousness (G-LOC)

摘要

G-Induced loss of consciousness (G-LOC) can occur when an aircraft flies in a tight circular pattern for extended periods exposing pilots to high acceleration forces. Centripetal acceleration results in an inertial reaction of equal but opposite force (G) to displace organs and blood towards extremities. In humans (with or without G protection devices), G-LOC can occur at or above +5 Gz, and is characterized by (caret) 15 s of absolute mental and physical incapacitation followed by equally long period of relative incapacitation. G-LOC occurs with a critical reduction in cerebral blood flow which has been measured in both baboons and human volunteers during 4+Gz and higher exposures in our centrifuge Even though the relationship between the reduction in CBF and +Gz exposure has been shown, little is known about its effect on brain physiology and metabolism. To address this problem a rodent-small animal centrifuge (SAC) model was developed at the Armstrong laboratory, Brooks Air Force Base, TX. The results of this unique and pioneering work are described in this report. This report describes the research conducted in the last three years on this contract. A major part of this research is presented as manuscripts of which some have been published, accepted for publication or have been submitted to journals for consideration. Also this research has been repented in many scientific meetings and abstracts of these presentations are also included. This report is organized in sections. Main objective of each section will be stated in the beginning and all results/publications/manuscript for that section will be presented.