Dual motor innervation in the axial musculature of fishes

This is the authors' abstract. We don't add key points for this paper.

A systematic survey of motor innervation in the myotomal muscle fibres in several groups of fishes was conducted to observe the extent of dual innervation, a phenomenon found within those myotomal muscle fibres with terminal innervation. It is concluded that the dually innervated myotomal muscle fibre is a primitive vertebrate feature. Furthermore, it is suggested that this particular form of polyneuronal innervation is retained in the course of neural evolution within the homogeneous white myotomal muscle fibre region in these fish groups in order to insure synchrony of firing during sudden, rapid locomotion. The findings are examined in light of current ideas regarding the direct adrenergic innervation in addition to cholinergic innervation of striated muscle fibres.