Stimulation-induced changes in the intracellular sodium activity of the crayfish stretch receptor.
Changes in intracellular Na+ activity (aiNa) caused by mechanical stimulation in the slowly adapting stretch receptor of the crayfish were examined using Na+-selective microelectrodes. A series of brief stretches (each giving rise to a brief receptor potential and a single action potential) induced a reversible increase in aiNa which was proportional to the stimulation frequency in the range examined, 0-9.5 Hz. At 9.5 Hz, aiNa increased by 4-5 mM from the resting value of 7-10 mM. Tetrodotoxin (TTX) reduced, but did not abolish the stimulation-dependent increase in aiNa indicating the involvement of a Na+-influx pathway in addition to the potential-dependent, TTX-sensitive sodium channels of the neuronal plasma membrane. A likely candidate for this TTX-resistant pathway are the cationic transducer channels of the dendrites.
D000818:Animals; D003400:Astacoidea / Q000502:physiology*; D004558:Electric Stimulation; D066298:In Vitro Techniques; D007473:Ion Channels / Q000187:drug effects; D008465:Mechanoreceptors / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D008564:Membrane Potentials; D012964:Sodium / Q000378:metabolism*; D013779:Tetrodotoxin / Q000494:pharmacology
D007473:Ion Channels; D013779:Tetrodotoxin; D012964:Sodium