Postsynaptic ERG potassium channels limit muscle excitability to allow distinct egg-laying behavior states in Caenorhabditis elegans.
J Neurosci
; 33(2): 761-75, 2013 Jan 09.
Article
en En
| MEDLINE
| ID: mdl-23303953
ABSTRACT
Caenorhabditis elegans regulates egg laying by alternating between an inactive phase and a serotonin-triggered active phase. We found that the conserved ERG [ether-a-go-go (EAG) related gene] potassium channel UNC-103 enables this two-state behavior by limiting excitability of the egg-laying muscles. Using both high-speed video recording and calcium imaging of egg-laying muscles in behaving animals, we found that the muscles appear to be excited at a particular phase of each locomotor body bend. During the inactive phase, this rhythmic excitation infrequently evokes calcium transients or contraction of the egg-laying muscles. During the serotonin-triggered active phase, however, these muscles are more excitable and each body bend is accompanied by a calcium transient that drives twitching or full contraction of the egg-laying muscles. We found that ERG-null mutants lay eggs too frequently, and that ERG function is necessary and sufficient in the egg-laying muscles to limit egg laying. ERG K(+) channels localize to postsynaptic sites in the egg-laying muscle, and mutants lacking ERG have more frequent calcium transients and contractions of the egg-laying muscles even during the inactive phase. Thus ERG channels set postsynaptic excitability at a threshold so that further adjustments of excitability by serotonin generate two distinct behavioral states.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Oviposición
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Sinapsis
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Conducta Animal
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Caenorhabditis elegans
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Canales de Potasio Éter-A-Go-Go
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Músculos
Límite:
Animals
Idioma:
En
Revista:
J Neurosci
Año:
2013
Tipo del documento:
Article
País de afiliación:
Estados Unidos