PMID: 753922Jan 1, 1978Paper

Electrical properties of phasic and tonic muscle fibres of the abdominal flexor muscles in crayfish

Journal of Physiology, Paris
J Lehouelleur

Abstract

Phasic and tonic abdominal flexor muscle fibres of two anatomically different muscles in the crayfish Procambarus clarkii or Astacus sp. were investigated using electrophysiological techniques. 1. In phasic muscle, fibres were electrically coupled. They were very tightly packed and could not be isolated. No coupling was observed in tonic fibres where single fibres could easily be isolated and their radii determined with precision to between 75 and 200 micron. 2. The electrical constants of phasic fibres (sarcomere length about 2.5 micron) were determined according to the "infinite" cable theory. The were : lambda = 0.5-1 mm, Ro = 30-40 k omega, Rm = 20-30 omega.cm2, Ri = 2-5 omega.cm and Cm = 3-4 microF/cm2. 3. In tonic fibres (sarcomere length about 8 micron) electrical constants were determined according to the equations for the "short cable". They differed considerably from one fibre to another : lambda ranged between 1.5-12 mm, Ro 0.15-1.6 M omega, Rm 700-1,100 omega.cm2, Ri 25-150 omega.cm and Cm 15-300 microF/cm2. 4. The current voltage relationship was linear in phasic fibres for both outward and inward currents not exceeding 0.75 microA. In tonic fibres there was a delayed rectification in about 95% of fibres; anomalous...Continue Reading

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.