Central pattern generators in the brainstem and spinal cord: an overview of basic principles, similarities and differences

Abstract

Central pattern generators (CPGs) are generally defined as networks of neurons capable of enabling the production of central commands, specifically controlling stereotyped, rhythmic motor behaviors. Several CPGs localized in brainstem and spinal cord areas have been shown to underlie the expression of complex behaviors such as deglutition, mastication, respiration, defecation, micturition, ejaculation, and locomotion. Their pivotal roles have clearly been demonstrated although their organization and cellular properties remain incompletely characterized. In recent years, insightful findings about CPGs have been made mainly because (1) several complementary animal models were developed; (2) these models enabled a wide variety of techniques to be used and, hence, a plethora of characteristics to be discovered; and (3) organizations, functions, and cell properties across all models and species studied thus far were generally found to be well-preserved phylogenetically. This article aims at providing an overview for non-experts of the most important findings made on CPGs inin vivoanimal models,in vitropreparations from invertebrate and vertebrate species as well as in primates. Data about CPG functions, adaptation, organization, and cellular properties will be summarized with a special attention paid to the network for locomotion given its advanced level of characterization compared with some of the other CPGs. Similarities and differences between these networks will also be highlighted.

The Effect of Intraspinal Micro Stimulation With Variable Stimulating Pattern in Adult Rat With Induction of Spinal Cord Injury in the Treatment of Spinal Cord Injuries

“…Observing the motion recovery in IES group conform to the previously reported studies. [20][21][22] However, our specific findings are related to the quality of motion recovery in VIES group. Because the effectiveness of such a stimulation profile has not addressed in the previous eminent studies.…”

“…Because the effectiveness of such a stimulation profile has not addressed in the previous eminent studies. [20][21][22] According to the observations, the lower the mass center values are, the less the spatial distribution of the points in the phase space is, and the more concentrated the points are. Since the value of the center of mass related to the VPIES group is less than that is related to the IES group, and it is closer to the healthy animal group.…”

“…For ages, researchers have indicated that there are neural circuits in the spinal cord, which generate neural orders related to the control of lower rhythmic motion. [14][15][16] The fascinating point is that the mentioned neural circuits can produce neural commands for rhythmic movement even without the effects of afferents and without receiving neural signals from the brain. Such neural circuits are called central pattern generators.…”

“…As a result of this process, gait can be retrieved. 8,[20][21][22] In all mentioned works, stimulation signals delivered to the spinal epidural region. The delivered electrical signals are periodic pulses.…”

Examples of Gibsonian Affordances in Legged Robotics Research Using an Empirical, Generative Framework

“…Robots are able to locomote using both very strong feed-forward control methods, such as central pattern generators (Saranli et al, 2001;Ijspeert et al, 2007;Ijspeert, 2008) as well as more distributed control (Cruse et al, 1998;Owaki et al, 2013;Owaki and Ishiguro, 2017;De and Koditschek, 2018) and many roboticists employ combinations thereof (Espenschied et al, 1996;Merel et al, 2019). Legged animals appear to pragmatically combine feedforward (Grillner, 1985;Whelan, 1996;Golubitsky et al, 1999;Minassian et al, 2017) and feedback (Pearson, 1995(Pearson, , 2004Steuer and Guertin, 2019) controllers, implemented physically in both the mechanics of the body and in the nervous system (Cruse et al, 1995(Cruse et al, , 2006Jindrich and Full, 2002;Sponberg and Full, 2008).…”