Contraction rates of muscles and measurements of the input and output parameters of the vestibulo-ocular reflex action in the Antarctic fish Pagothenia borchgrevinki

In order to fully describe the input and output parameters of the vestibulo-ocular reflex, simultaneous recordings are required of head movement, sensory input from the semicircular canals, motor neuron dischange and eye movement relative to the head. Contraction rates (time) in blocks of muscle cut from freshly killed Pagothenia borchgrevinki were measured after the application of an electrical stimulating pulse directly to the muscle. Recordings were made with microelectrodes from the exposed brain (forebrain was ablated to eliminate perception of pain and recordings were from the hindbrain) of an otherwise intact fish perfused with water in a perspex holding chamber. Head movement and eye movement were monitored alternately with an optoelectronic movement detector. Large numbers of vestibular sensory cells and lateral line neurons were recorded.