Lithium chloride and immunomodulation in taste aversion conditioning.

Lithium chloride has been used in many studies of conditioning to induce taste aversion behaviour, and in some experiments investigating conditioning effects on immunity it has been used on the assumption that it is immunologically neutral. The studies reported here, however, indicate that LiCl is not immunologically neutral and when used to endow a UCS with noxious properties to enhance the behavioural response in taste aversion conditioned immunosuppression, it may antagonize the residual immunosuppression following initial UCS administration and also the conditioned immunosuppression occurring after CS reexposure. Therefore, conclusions drawn from studies of behaviourally conditioned immunomodulation where LiCl is used as part of either the CS or UCS may require reevaluation.