A possible mechanism for diisopropylfluorophosphate-induced memory loss in rats.
Passive avoidance retention and cortical [H3]-quinuclidinyl benzilate (QNB) binding were examined in rats that were chronically treated with diisopropylfluorophosphate (DFP), an irreversible acetylcholinersterase inhibitor. Retention of a passive avoidance response in DFP-treated rats was significantly lower when compared to vehicle-treated controls. Passive-avoidance retention decreased from 93% in control animals to 68% in DFP-treated rats. QNB binding studies revealed the density of muscarinic receptors in cortical homogenates was significantly reduced from 0.95 +/- 0.04 pmole/mg protein in controls to 0.72 +/- 0.04 pmole/m protein in DFP-treated rats. Scatchard analysis of QNB binding curves did not reveal a decrease in affinity of muscarinic receptors for QNB. Based on data that DFP causes a reduction in cholinergic receptors, this study supports the hypothesis that central cholinergic receptors are associated with mechanisms involved in memory storage.
D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D001522:Behavior, Animal / Q000187:drug effects; D007531:Isoflurophate / Q000633:toxicity*; D008297:Male; D008568:Memory / Q000187:drug effects*; D011813:Quinuclidinyl Benzilate; D051381:Rats; D011919:Rats, Inbred Strains; D011950:Receptors, Cholinergic / Q000187:drug effects; D013997:Time Factors
D011950:Receptors, Cholinergic; D007531:Isoflurophate; D011813:Quinuclidinyl Benzilate