The involvement of brain structures in the adjuvant effect of muramyl dipeptide.

With the aid of small electrolytic lesions we have studied the possible participation of brainstem structures in the adjuvant activity of muramyl dipeptide (MDP). The results suggest the involvement of the serotonergic groups B6.7.8 and serotonergic pathways in the upper region of the reticular formation. Since lesions in the caudal parts of reticular formation in the area of aminergic groups A1.3.5.7 with the participation of corresponding pathways also influenced the adjuvant effect of MDP the possible role of noradrenaline is also implicated.