Neurochemical sensitization associated with systemic administration of tumor necrosis factor-α: Adjuvant action in combination with bovine serum albumin

Tumor necrosis factor-alpha (TNF-α) provokes a time-dependent sensitization of brain monoamine activity, plasma corticosterone activity and sickness behavior, the latter being reminiscent of septic or anaphylactic shock. In this investigation, bovine serum albumin (BSA) elicited similar corticosterone and sickness profiles, whereas the monoamine changes were not observed. The sensitization elicited by mTNF-α plus BSA was markedly greater that that elicited by BSA alone. Carrier-free TNF-α promoted the sensitization of brain monoamine activity, but not sickness or corticosterone. It is suggested that mTNF-α acts as an adjuvant to the anaphylactic actions elicited by BSA, but may provoke a sensitization of monoamine activity which is time-dependent and varies across brain regions.