Selective breeding for sensitivity to DFP: generalization of effects beyond criterion variables

Area of Science:

• Neuroscience
• Pharmacology
• Toxicology

Background:

• Organophosphates, such as DFP, are anticholinesterase agents with known neurotoxic effects.
• Selective breeding can alter an organism's sensitivity to specific chemical agents.
• Understanding the generalization of DFP effects is crucial for assessing its neurotoxicity.

Purpose of the Study:

• To investigate the generalization of DFP effects in rats selectively bred for varying sensitivities.
• To determine if DFP's impact extends beyond the initially selected traits.

Main Methods:

• Utilized two lines of Sprague-Dawley derived rats selectively bred for differential sensitivity to DFP.
• Assessed DFP effects on core body temperature, body weight, operant responding, locomotor activity, analgesia, and aversive escape responses.
• Compared incidence of peripheral effects like diarrhea between the rat lines.

Main Results:

• Flinders S-line rats remained more sensitive to DFP's effects on core body temperature, body weight, and operant water reward responding.
• DFP also showed generalized increased sensitivity in the Flinders S-line for locomotor activity, FR5 responding, and analgesia.
• Diarrhea incidence was similar in both lines, unaffected by DFP, and higher in males. Escape responses under aversive motivation were not affected by DFP.

Conclusions:

• DFP's neurotoxic effects generalize beyond selected variables but are relatively specific.
• The observed changes in sensitivity are consistent with alterations in central cholinergic system functioning.
• Selective breeding offers a model to study the specificity of neurochemical agent effects.