Nicotinic acetylcholine receptors (nAChRs) at zebrafish red and white muscle show different properties during development
- Ahmed, K.T., Ali, D.W.
- Developmental Neurobiology 76(8): 916-36 (Journal)
- Registered Authors
- MeSH Terms
- Embryo, Nonmammalian/physiology*
- Muscle Fibers, Fast-Twitch/physiology*
- Muscle Fibers, Slow-Twitch/physiology*
- Neuromuscular Junction/physiology*
- Patch-Clamp Techniques
- Polymerase Chain Reaction
- Receptors, Nicotinic/physiology*
- Time Factors
- 26585318 Full text @ Dev. Neurobiol.
Ahmed, K.T., Ali, D.W. (2016) Nicotinic acetylcholine receptors (nAChRs) at zebrafish red and white muscle show different properties during development. Developmental Neurobiology. 76(8):916-36.
Nicotinic acetylcholine receptors (nAChRs) are highly expressed at the vertebrate neuromuscular junction (NMJ) where they are required for muscle activation. Understanding the factors that underlie NMJ development is critical for a full understanding of muscle function. In this study we performed whole cell and outside-out patch clamp recordings, and single-cell RT-qPCR from zebrafish red and white muscle to examine the properties of nAChRs during the first 5 days of development. In red fibers miniature endplate currents (mEPCs) exhibit single exponential time courses at 1.5 days post fertilization (dpf) and double exponential time courses from 2 dpf onwards. In white fibers, mEPCs decay relatively slowly, with a single exponential component at 1.5 dpf. By 2 and 3 dpf, mEPC kinetics speed up, and decay with a double exponential component, and by 4 dpf the exponential decay reverts back to a single component. Single channel recordings confirm the presence of two main conductance classes of nAChRs (∼45 pS and ∼65 pS) in red fibers with multiple time courses. Two main conductance classes are also present in white fibers (∼55 pS and ∼73 pS), but they exhibit shorter mean open times by 5 dpf compared with red muscle. RT-qPCR of mRNA for nicotinic receptor subunits supports a switch from γ to ε subunits in white fibers but not in red. Our findings provide a developmental profile of mEPC properties from red and white fibers in embryonic and larval zebrafish, and reveal previously unknown differences between the NMJs of these muscle fibers.
Genes / Markers
Mutation and Transgenics
Human Disease / Model Data
Sequence Targeting Reagents
Engineered Foreign Genes
Errata and Notes