Accession Number:

ADA539476

Title:

Changes in Extracellular Striatal Acetylcholine and Brain Seizure Activity Following Acute Exposure to Nerve Against in Freely Moving Guinea Pigs

Descriptive Note:

Journal article

Corporate Author:

ARMY MEDICAL RESEARCH INST OF CHEMICAL DEFENSE ABERDEEN PROVING GROUND MD PHARMACOLOGY BRANCH

Report Date:

2010-01-01

Pagination or Media Count:

11.0

Abstract:

Organophosphorus nerve agents irreversibly inhibit acetylcholinesterase AChE in the peripheral and central nervous systems, causing an increase in the concentration of acetylcholine ACh in the synapse or neuromuscular junction and subsequent adverse effects. In this study, in vivo microdialysis was utilized to collect samples from the striatum for monitoring changes in extracellular ACh levels along with cortical electroencephalographic EEG recordings for identifying seizure activity after acute subcutaneous s.c. exposure to 1.0 x LDso of the nerve agents sarin, soman, or one of two V-type agents VX, or a Russian V-agent, designated VR in unanesthetized freely moving guinea pigs. Based on EEG recordings, these animals were subsequently divided into groups that developed seizures 5 and those that did not develop seizures N5. Maximum ACh levels in the striatum were observed at 60-70 min for sarin and soman 5 groups and 105 min for VX and VR 5 groups. In all N5 groups the greatest increase in extracellular ACh occurred within 30 min after exposure, although in the sarin N5 group a few sporadic increases of ACh from control occurred. Animals that developed seizures, regardless of the nerve agent, had significantly higher extracellular striatal ACh levels compared to the controls or those animals that did not develop seizures, yet both 5 and N5 groups displayed similar levels of blood AChE inhibition. Regardless of the agent, all animals in the non-seizure groups survived 24 h, while lethality 25-42 was observed only in animals that experienced seizure activity.

Subject Categories:

  • Biochemistry
  • Medicine and Medical Research

Distribution Statement:

APPROVED FOR PUBLIC RELEASE