[Histochemistry, immunocytochemistry, and biometry of muscle fibers and their innervation of the peroneus longus muscle].

The morphology of the peroneus longus muscle of the Chinese quail was studied in relation to partial behavorial characteristics. On the basis of the actomyosin ATPase reaction after alkaline and acid preincubation, three fiber types are revealed. The indirect immunofluorescence, using specific antibodies against 'slow' myosin from the human vastus lateralis muscle, provokes a strong reaction on the small fiber type. The characteristics of the innervation revealed by the cholinesterase activity, concentrated in the synaptic gutters and the direct study of the nerve fibres, show focal, mono-axonal 'en plaques' endings, typical of the phasic motor system.