Intracellular recording of identified dorsal spinocerebellar tract neurones from guinea pig spinal cord in vitro

Abstract

Recent studies on the monosynaptic connection between primary afferent fibres and dorsal spinocerebellar tract (DSCT) neurones in the spinal cord of anaesthetized cats have been undertaken to investigate the mechanisms of excitatory synaptic transmission in the mammalian central nervous system. The need to extend these observations to a study of the effects of changes in the extracellular environment of DSCT neurones prompted us to develop the in vitro preparation described in this paper. We have developed an isolated spinal cord preparation from young guinea pigs, in which DSCT neurones can be identified and recorded from intracellularly. The spinal cord can be maintained in vitro for at least 7 hours. This preparation is sufficiently stable to allow intracellular penetration of DSCT cells in excess of 2 h, with resting membrane potentials of -65 mV obtainable. Reconstruction of neurones stained with horseradish peroxidase confirmed their location in Clarke's column. The dendritic morphology of the reconstructed DSCT neurones was found to be similar to DSCT neurones described in the cat spinal cord. Since the motor system of the guinea pig is quite advanced at birth, this preparation should provide a valid extension to in vivo results on neuronal membrane properties and synaptic potentials in DSCT neurones.