The Efflux of Potassium from Electroplaques of Electric Eels

Abstract

ABSTRACT1. T h e m o v e m e n t of labeled potassium ions has been measured across the innervated m e m b r a n e s of single isolated electroplaques, obtained from the organ of Sachs of Electrophorus electricus, m o u n t e d in an a p p a r a t u s which allowed a separate washing of the two membranes.2. Equations have been derived for a 3 c o m p a r t m e n t system in series in which tracer from a large pool in one outer c o m p a r t m e n t is collected in the other outer c o m p a r t m e n t . T h e a m o u n t of unlabeled ion in the middle c o m p a r tm e n t m a y be calculated and also the fluxes across the two membranes.3. T h e flux of potassium across the innervated m e m b r a n e s of resting cells in a steady state was between 700 to 1000 #/zmoles/cm.2/sec. and was unaffected by d-tubocurarine.4. Direct stimulation of electroplaques with external electrodes caused an increase in the effiux of potassium from the innervated m e m b r a n e of 5 to 8 /~/~moles/cm.~/impulse, which was unaffected by d-tubocurarine; no change occurred in the efflux across the non-innervated m e m b r a n e .5. It is concluded that the discharge of electroplaques is a c c o m p a n i e d by a small outward m o v e m e n t of potassium ions across the innervated m e m b r a n e of the same order of m a g n i t u d e as that found on excitation of squid giant axons. T h e d a t a show a basic similarity of potassium movements across these two entirely different types of conducting membranes and suggest that this p h e n o menon m a y be a general feature of bioelectric currents p r o p a g a t i n g an action potential.

Flexoelectricity of Multifunctional Polymer Electrolyte Membranes: Effect of Polymer Network Functionality

“…on the order of 10 –5 –10 –2 μC/m. ,− , In nature and biological systems, the electricity generation was found to occur from a different mechanism, that is through ionic polarization involving repolarization and depolarization. For example, electric eels produce bioelectricity for hunting or defending through the cells called electroplaques, utilizing the passive and active ion transportation across the cell membranes. − Other examples include electrical signals in our nervous systems and in the ears where flexoelectricity generation within the hair cells in the inner ears is the primary source for sensing of sounds . Moreover, flexoelectricity generation (∼10 –5 μC/m) within the bone was also reported to be responsible for bone healing, i.e.…”

Mechanoelectrical Conversion in Highly Ionic Conductive Solid‐State Polymer Electrolyte Membranes

“…Neuron cells, for instance, can generate and transport electrical signals throughout our nervous systems based on the aforementioned action potentials . Similarly, specific cells called electroplaques found in electric eels can produce bioelectricity, which help those creatures to defend and hunt . These fascinating phenomena that mimic biological cell membranes have inspired researchers to examine the bioelectricity generation in living cells in order to develop energy conversion devices .…”

“…[4] Similarly, specific cells called electroplaques found in electric eels can produce bioelectricity, which help those creatures to defend and hunt. [5,6] These fascinating phenomena that mimic biological cell membranes have inspired researchers to examine the bioelectricity generation in living cells in order to develop energy conversion devices. [7,8] In recent years, researchers have found some interesting flexoelectric effect in bioelectricity generation, including ion transport in cell membranes, [9] bone regeneration, [10] and stereocilia hairs moderately to heavily plasticized PEGDA/SCN/LiTFSI systems.…”

Flexoelectric Ionic Liquid-Grafted Triblock Copolymers for Energy Harvesting under Flexural Deformation

“…The range of the flexoelectric coefficient (μ) depends largely on the material’s composition and the strength of polarization. For instance, in biological systems including the auditory system, bone repair, and animal defense mechanisms, the flexoelectric coefficients are on the order of 10 –12 –10 –5 μC/m, where the polarization takes place via active or passive manipulation of the ion concentration gradients across the cell membrane . In biomembranes formed by molecules with hydrophilic and hydrophobic tails, small compression in the thickness direction alters the charge distribution at the top and bottom surfaces of the membrane, which results in flexoelectric coefficient values around 10 –18 μC/m .…”

“…On the other hand, in synthetic materials like cavitated polyolefins, polyethylene terephthalate, electroactive polymers, or ferroelectric ceramics, polarization is the response to dipolar molecular reorientation upon applied deformation. These materials exhibit μ in the ranges from 10 –5 to 100 μC/m. ,− This opens a new opportunity to further develop materials with a larger flexoelectric response and to better improve our fundamental understanding of this intriguing phenomenon.…”