A Model of Military Deployment: Effects of Psychological Stress and Caffeine Use on Information Processing in Male Rats
Abstract
Military Service Members consume caffeine in large quantities to maintain performance, particularly in deployed settings under chronic stress and sleep-deprived conditions. Some researchers argue that stimulant drugs consumed in theater worsen Service Members mental health, potentially contributing to incidence of mental health disorders. However, empirical studies suggest chronic caffeine consumption is associated with psychological and physical health benefits. It is unclear how chronic caffeine consumption affects Service Members mental health. An animal experiment was used to investigate how caffeine (caf), a model of Warrior Stress (WS), and combined WS and sleep disruption (SDis) conditions impact behavioral measures of information processing in a 2 (no caffeine, caffeine) x 2 (no stress, stress) nested design with repeated measures (baseline, 7 days WS, 14 days WS SDis, for stressed groups). Acoustic startle response with and without pre-pulse and locomotor habituation to an open field were used as primary outcome measures because they involve basic non-conscious processes that serve as an important bridge between human and animal research as indices of cognitive function. Seven days of sleep disruption was nested within the Warrior Stress groups. Results indicated that the Time x Caf x WS interaction was significant for Initial Startle Amplitude and approached significance for Startle Amplitude in response to the 110 dB startle/68 dB pp only. Caf increased Initial Startle for non-stressed rats only at Time 2 (post WS SDis). In addition, there were main effects for WS and Time on percent inhibition for 110 dB startle/68 dB only, such that WS decreased inhibition over time. There were significant main effects for Caf and WS on body weight (BW), indicating that caffeinated and stressed rats had less increases in BW over time (emerged after start of SDis). Caf and WS did not demonstrate robust effects across measures of information processing.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 25, 2015
- Accession Number
- AD1127846
Entities
People
- Margaret C. Baisley
Organizations
- Uniformed Services University of the Health Sciences