Abstract
Superfusion of the cockroach (Periplaneta americana) giant axon by ethanol (0.5-2%) produces conditions which allow the generation and active propagation of two kinds of regenerative potentials. (a) The classical action potential with a threshold at about 30 mV above resting potential, an amplitude of about 105 mV, a duration of 1-2 ms, and a conduction velocity of 3-6 m/s. (b) A smaller depolarizing potential (SDP) with a threshold of 5-15 mV above resting level, an amplitude of 10-30 mV, a duration of several hundred ms and a conduction velocity of 0.1-0.6 m/s. The SDP is associated with a small increase in conductance (10-15%), and is abolished by tetrodotoxin (10-6 M) or by removing extracellular sodium. The amplitude of the SDP slightly increases when the extracellular Ca2+ concentration is elevated and is reduced at low (Ca2+)0 concentration; however, it is not blocked in a solution containing high Mg2+ (19 mM), low Ca2+ (1 mM) concentrations, indicating that inward Ca2+ current is not required for the generation of SDP.
Original language | English |
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Pages (from-to) | 164-168 |
Number of pages | 5 |
Journal | Brain Research |
Volume | 398 |
Issue number | 1 |
DOIs | |
State | Published - 19 Nov 1986 |
Keywords
- Action potential
- Axon
- Ethanol