An analysis of the bursting behaviour of the Aplysia R15 neurone during exposure to normoxia and hypoxia with and without external calcium present.
Membrane potentials (EM), interburst intervals (IBI), burst durations (BD), the numbers of spikes within a burst, and the amplitudes of the burst pacemaker potentials (BPP) were measured in two groups (N = 7 per group) of R15 neurones under conditions of 20, 10 and 5% oxygen and under nitrogen equilibration in suffusates with either Ca2+ (10 mM) or Mg2+ (10 mM) present (Groups I and II). Under normal extracellular Ca2+ conditions, EM and the amplitude of the BPP for Group I R15 neurones increased progressively during hypoxia and reoxygenation. In the absence of external calcium, the normal bursting pattern of Group II R15 neurones was interrupted. No consistent relationships were observed among BD, IBI, and the number of spikes per burst with respect to EM or BPP. Hypoxia may alter the resting permeability of R15 to potassium as well as having ephaptic effects.
D000332:Aerobiosis; D000693:Anaerobiosis; D000818:Animals; D001048:Aplysia; D002118:Calcium / Q000494:pharmacology; D005724:Ganglia / Q000502:physiology; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D009474:Neurons / Q000187:drug effects / Q000502:physiology*
D002118:Calcium