Central pattern generators and the control of rhythmic movements

Abstract

Central pattern generators are neuronal circuits that when activated can produce rhythmic motor patterns such as walking, breathing, flying, and swimming in the absence of sensory or descending inputs that carry specific timing information. General principles of the organization of these circuits and their control by higher brain centers have come from the study of smaller circuits found in invertebrates. Recent work on vertebrates highlights the importance of neuro-modulatory control pathways in enabling spinal cord and brain stem circuits to generate meaningful motor patterns. Because rhythmic motor patterns are easily quantified and studied, central pattern generators will provide important testing grounds for understanding the effects of numerous genetic mutations on behavior. Moreover, further understanding of the modulation of spinal cord circuitry used in rhythmic behaviors should facilitate the development of new treatments to enhance recovery after spinal cord damage.

Mas‐allatotropin in the developing antennal lobe of the sphinx moth Manduca sexta: Distribution, time course, developmental regulation, and colocalization with other neuropeptides

“…To date, neuropeptides are accepted as molecules responsible for shaping the activity pattern of neuronal circuits and thus as being of major importance for the functional condition and output pattern of the nervous system (Hökfelt, 1991;Marder and Bucher, 2001;Nusbaum et al, 2001;Nässel, 2002). In insects, a few studies on the role of neuropeptides revealed important functions in the brain, e.g.…”

Strategies for delineating spinal locomotor rhythm-generating networks and the possible role of Hb9 interneurones in rhythmogenesis

“…Either mechanism (or a combination of the two) may lead to stable, alternating rhythm generation see (Marder and Bucher, 2001;Getting, 1989;Perkel, 1976). It is interesting to note that, based on research in invertebrates, Getting (1986) predicted that, to generate an intermittent bursting pattern as seen during mammalian locomotion, the neurones involved in rhythm generation would likely be conditional bursters.…”

Modeling discrete and rhythmic movements through motor primitives: a review

“…According to Marder and Bucher (2001), two types of CPG networks can be distinguished: the so-called pacemaker-driven networks and networks with emergent rhythms. Pacemaker-driven networks, which are usually networks that are always active, as in breathing, consist of a subnetwork of intrinsically oscillating neurons that drives non-bursting neurons into a cyclic pattern, while in networks with emergent rhythms, the oscillatory pattern comes from couplings between the neurons, for instance by mutual inhibition of two reciprocal neurons.…”

“…Indeed, discrete networks need to encode a target position and possibly a time of onset, while rhythmic networks also need to be endowed with a notion of frequency and phase. As reviewed by Marder and Bucher (2001), such features seem to emerge naturally from the intrinsic and synaptic properties of the neurons constituting these particular (rhythmic) CPGs.…”

“…Cybern, 1985. In this article, Matsuoka (1985) proposes a model for oscillating neural networks. As discussed in section 5, it has been observed that oscillatory behaviors can emerge from networks of mutually inhibiting neurons (see for instance Marder and Bucher (2001)). …”