Enzymatic differentiation of muscle fibre types in embryonic Latissimus dorsii of the chick: effects of spinal cord stimulation

Abstract Myofibrillar ATPase differentiation in anterior latissimus dorsi (ALD) and posterior latissimus dorsii (PLD) muscles has been studied in chick embryo. At stage day 8, ALD fibres have acid-stable ATPase while the enzymatic activity is acid-labile in PLD fibres. In older stages, PLD exhibits α and β fibres which both have a single spot of acetyl cholinesterase (ACHE) activity. Electrical spinal cord stimulation performed for several days from day 10 of incubation leads to an increase in β fibre-type ratio in PLD, these β fibres exhibit a multiplicity of ACHE spots and are assumed to be multiinnervated.