AI Article Synopsis
- Nerve agents, like soman, are powerful compounds used in chemical warfare that inhibit a crucial enzyme (acetylcholinesterase), leading to serious neurological damage, even from sub-lethal doses.
- This study focused on monitoring changes in oxygen levels in the cortex and hippocampus of rats after exposure to a sub-lethal dose of soman.
- The findings showed distinct patterns of oxygenation changes before and after convulsive seizures, indicating that real-time brain oxygen measurements could serve as a sensitive marker for nerve agent exposure and aid in treatment evaluations.
Article Abstract
Nerve agents (NAs) are potent organophosphorus (OP) compounds with applications in chemical warfare. OP compounds act by inhibiting acetylcholinesterase (AChE). Soman (O-pinacolyl methylphosphonofluoridate) is one of the most potent NAs. It is well known that small doses of NAs can be lethal, and that even non-lethal exposure leads to long-term mental debilitation/neurological damage. However, the neuropathology following exposure to sub-lethal nerve agents is not well understood. In this study, we examined changes in tissue oxygenation (pO) in the cortex and hippocampus after a sub-lethal dose of soman [80-90 μg/kg; subcutaneous]. pO changes can provide information regarding oxygen delivery and utilization and may be indicative of a disruption in cerebral blood flow and/or metabolism. Changes in oxygenation were measured with chronically implanted oxygen sensors in awake and freely moving rats. Measurements were taken before, during, and after soman-induced convulsive seizures. Soman exposure resulted in an immediate increase in pO in the cortex, followed by an even greater increase that precedes the onset of soman-induced convulsive seizures. The rise in hippocampus pO was delayed relative to the cortex, although the general pattern of brain oxygenation between these two regions was similar. After convulsive seizures began, pO levels declined but usually remained hyperoxygenated. Following the decline in pO, low frequency cycles of large amplitude changes were observed in both the cortex and hippocampus. This pattern is consistent with recurring seizures. Measuring real-time changes in brain pO provides new information on the physiological status of the brain following soman exposure. These results highlight that the measurement of brain oxygenation could provide a sensitive marker of nerve agent exposure and serve as a biomarker for treatment studies.
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| http://dx.doi.org/10.1016/j.neuro.2018.01.007 | DOI Listing |
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