An in vivo method for studying afferent fibre activity from cervical paravertebral tissue during vertebral motion in anaesthetised cats

We describe a method for characterizing and studying afferent input to the central nervous system arising from deep axial structures of the neck during defined cervical vertebral movement. Multiple or single unit recordings of afferent activity arising from identified receptive fields in these tissues can now be studied in situ while simultaneously inducing `natural' stimulation of mechanoreceptors during well defined movements of the intact vertebral column. When combined with existing strategies for extracellular and intracellular recordings of neurones, the methods described here will allow in vivo investigation of the central effects of functionally identified afferents innervating identified receptive fields located in deep paravertebral tissues during a variety of discrete movements of individual vertebra. This has particular importance in determining the relative role that afferents innervating specific axial tissues have on identified neurones in the central nervous system. It will allow determination of the `bias' of input to projection cells, such as `hyperconvergent' neurones, during natural movement. Furthermore, it will allow investigation of their role in the control of somatic and autonomic reflex behaviour.