Active Transport of Potassium by the Giant Neuron of the Aplysia Abdominal Ganglion
Overview
Authors
Affiliations
We measured the internal potassium activity, a(i) (K), and membrane potential, E(m), simultaneously in 111 R2 giant neurons of Aplysia californica. a(i) (K) was 165.3 +/- 3.4 mM, E(m) was -47.8 +/- 0.9 mv, and E(K) calculated using the Nernst equation was -76.9 +/- 0.05 mv. Such values were maintained for as long as 6 hr of continuous recording in untreated cells, a(i) (K) fell exponentially after the following treatments: cooling to 0.5 degrees -4 degrees C, ouabain, zero external potassium, 2,4-dinitrophenol, and cyanide. The effects of cooling and zero potassium were reversible. Potassium permeability was calculated from net potassium flux using the constant field equation and ranged from 2.6 to 18.5 x 10(-8) cm/sec. We conclude that potassium is actively transported into this neuron against a 30-40 mv electrochemical gradient.
EbrahimAmini A, Stefanovic B, Carlen P Biomedicines. 2022; 10(7).
PMID: 35884873 PMC: 9312484. DOI: 10.3390/biomedicines10071568.
Neural shutdown under stress: an evolutionary perspective on spreading depolarization.
Robertson R, Dawson-Scully K, Andrew R J Neurophysiol. 2020; 123(3):885-895.
PMID: 32023142 PMC: 7099469. DOI: 10.1152/jn.00724.2019.
Johnston D J Physiol. 1980; 298:145-57.
PMID: 7359382 PMC: 1279107. DOI: 10.1113/jphysiol.1980.sp013072.
Cellular basis of the photoresponse of an extraretinal photoreceptor.
Andresen M, Brown A Experientia. 1982; 38(9):1001-6.
PMID: 6290258 DOI: 10.1007/BF01955343.
The effect of phloretin on the potassium conductance in Aplysia giant neurons.
OWEN J J Membr Biol. 1974; 16(1):65-78.
PMID: 4837995 DOI: 10.1007/BF01872407.