Techniques to Study Spinal-Cord, Peripheral Nerve, and Muscle Activity in Freely Moving Animals

In the past dozen years, newly developed chronic recording techniques have made possible the direct study of peripheral nerve and spinal cord function in conscious, freely moving animals. Two complementary approaches were introduced in the mid-1970s: floating microelectrodes to record the activity of single neurons, and nerve cuff electrodes to record the activity of neuronal populations. Thus far, these techniques have been largely implemented in two areas of research: the functional roles in the control of posture and movement of several kinds of peripheral neurons have been assessed by recording their activity patterns in alert, unrestrained animals, and contrasting these to the activity present during stereotyped movements in more classical decerebrate, anesthetized, or otherwise reduced preparations; and the development, plasticity, and disorders of the neuromuscular system have begun to be studied in longitudinal experiments carried out in individual animals. Important new insights on the function of the peripheral nervous system have already emerged through the use of these novel experimental approaches.