Tetanic potentiation in motor units of rat medial gastrocnemius

• Authors: M. Piotrkiewicz , J. Celichowski
• Languages of publication: EN

Abstracts

EN

Tetanic potentiation is a phenomenon, which expresses the ability of a motor unit (MU) to increase its force output in tetanic contractions above that predicted with an assumption of algebraic summation of single twitch responses. To quantify tetanic potentiation, a coefficient TPC (tetanic potentiation coefficient) was defined as a ratio of the areas below tetanic force recording corresponding to the single stimulus contribution and that of the single twitch. Single MUs (27 Slow, 71 Fast, Fatigue Resistant, and 47 Fast, Fatigable) were isolated from the rat medial gastrocnemius muscle (MG) by ventral root splitting. TPC value was rate-dependent, with the maximum TPCmax at a certain optimal rate. The largest values of the TPCmax were obtained in the weakest and most fatigue resistant (S and weak FR) MUs. The different manifestation of staircase effect, post-tetanic and tetanic potentiation in individual MU types indicates that these phenomena may be independent of each other. We suggest that these phenomena as well as the fatigue resistance should be reexamined with protocols adjusted to the MU optimal frequency.

Keywords

EN

MOTOR UNIT; RAT; TETANIC POTENTIATION

Discipline

• EXPERIMENTAL_BIOLOGY_&_MEDICINE: EXPERIMENTAL BIOLOGY & MEDICINE

• Publisher: Marceli Nencki Institute of Experimental Biology, Polish Academy of Sciences
• Journal: Acta Neurobiologiae Experimentalis
• Year: 2007
• Volume: 67
• Issue: 1
• Pages: 35-42

Contributors

author

M. Piotrkiewicz

author

J. Celichowski

• Document Type: ARTICLE
• Publication order reference: Maria Piotrkiewicz, Institute of Biocybernetics and Biomedical Engineering, 4 Ks. Trojdena St., 02-109 Warsaw, Poland