Complex maze performance during carbon monoxide exposure in rats.

Area of Science:

• Toxicology
• Animal Behavior
• Fire Safety Research

Background:

• Residential fire victims often succumb to smoke inhalation, with high carboxyhemoglobin levels implicated.
• The incapacitation mechanism preventing escape from toxic gases, even at distances from flames, remains unclear.

Purpose of the Study:

• To develop an animal model for assessing the impact of toxic gases on escape behavior.
• To investigate the effects of carbon monoxide (CO) exposure on rats' ability to navigate a complex maze.

Main Methods:

• Rats were trained to navigate an 8-choice-point maze for water reward after a 24-hour water deprivation period.
• Following habituation, rats were exposed to varying concentrations of carbon monoxide (2000-4000 ppm) and their maze performance was assessed.
• Post-exposure, rats underwent further CO exposure with blood sampling to monitor carboxyhemoglobin levels.

Main Results:

• Increasing carbon monoxide concentrations significantly increased maze running times.
• Higher CO levels led to a decreased number of rats successfully reaching the goal.
• At 3500 ppm CO, no rats could reach the goal, and at 2000 ppm, non-completing rats traveled farther than successful ones.

Conclusions:

• Carbon monoxide exposure demonstrably impairs cognitive and motor functions essential for escape behavior.
• This rat maze model effectively demonstrates CO's incapacitating effects, providing insights into fire victim behavior.
• Findings underscore the critical danger of CO in residential fires, even at locations remote from the fire source.