American Society of Hirudotherapy

Neural circuits for generating rhythmic movements

Research article published in Annual review of biophysics and bioengineering (1978)

Last Updated: March 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Genomics & ProteomicsFriesen W, Stent G · Annual review of biophysics and bioengineering, 1978

Abstract

Inasmuch as the identified neural circuits discussed in this review pertain only to the nervous systems of two invertebrate species, one may ask whether or not these findings are generally applicable to central nervous oscillators that generate rhythmic movements in animals of other species and phyla, particularly in the vertebrates. This question is not easy to answer at this time, because detailed cellular network analyses thus far have been possible only in a very few neurophysiologically favorable preparations, such as those presented by the cardiac and stomatogastric ganglia of the lobster and the segmental ganglion of the leech. Nevertheless it is significant that the mechanisms according to which these invertebrate circuits are now thought to generate their oscillations--endogenous rhythmic polarization, reciprocal inhibition, and recurrent cyclic inhibition--were all first proposed to account for generation of rhythmic movements in vertebrate animals (7-9, 51, 71, 79). Moreover, the pattern of motor neuron activity in rhythmic movements of vertebrates is not necessarily more complex than the corresponding pattern in analogous movements of invertebrates. Therefore, the very much greater number of neurons in the central nervous system of vertebrates does not necessarily imply a greater complexity of the central oscillators that generate their rhythmic movements; it may only place greater obstacles in the way of identifying the underlying neuronal circuitry. In any case, it is worthy of note that the current list of fundamentally different and theoretically plausible types of neuronal oscillators is not only quite short but also of long standing. Thus, on these grounds, it seems reasonable to expect that the identified circuits discussed here will prove to be of general applicability to the generation of rhythmic movements in the whole animal kingdom.

Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.

Publication typeJournal ArticleResearch Support, U.S. Gov't, Non-P.H.S.Research Support, U.S. Gov't, P.H.S.Review
Indexed MeSH termsAnimalsLeechesLocomotionModels, NeurologicalMovementMyocardial ContractionNephropidaeNerve NetNervous System Physiological PhenomenaNeural InhibitionPeriodicityStomach

Summary

Inasmuch as the identified neural circuits discussed in this review pertain only to the nervous systems of two invertebrate species, one may ask whether or not these findings are generally applicable to central nervous oscillators that generate rhythmic movements in animals of other species and phyla, particularly in the vertebrates.

Why This Matters for Hirudotherapy

Expands the genomic and molecular understanding of medicinal leeches and their bioactive repertoire.

Citation

Neural circuits for generating rhythmic movements.

Friesen W, Stent G · Annual review of biophysics and bioengineering, 1978

Added to ASH library: March 18, 2026 · Site last updated: March 18, 2026

This website provides educational information and does not constitute medical advice, diagnosis, or treatment recommendations. Medicinal leech therapy carries clinically meaningful risks and should be performed only by qualified clinicians under institutionally approved protocols. FDA 510(k) clearance for medicinal leeches is limited to specific indications; investigational and off-label discussions are labeled accordingly. For patient-specific guidance, consult a qualified healthcare provider.

Neural circuits for generating rhythmic movements | ASH