.... In approximately 12% of the applied stimulations, the localized response was immediately followed by a propagating wave of activity that spread from the excited area at a rate of ∼0.9 cm s −1 ( Fig. 2 B). The direction of propagation was typically not symmetrical with respect to the localized response. No pattern...

... electrocytes are responsible for a main triphasic complex. Group I species exhibit a characteristic cephalic extension of the EO. Group II species exhibit an early positive component of putative neural origin, and strong EO auto-excitability. Group III species exhibit an early, slow, negative wave of abdominal...

... rate. The reversal potential for the 5-HT-induced hyperpolarization was −88.7 mV, suggesting the involvement of an enhanced K + conductance. Input/output curves measuring the number of action potentials evoked by current injection demonstrated a 5-HT-induced reduction in B5 neuronal excitability...

..., an increase in soma excitability and spike duration, and a decrease in spike threshold and afterhyperpolarization. In addition, simultaneous crush of both the cerebral and pedal nerves in the same animals produced alterations in the cerebral J/K sensory neurones and pleural VC sensory neurones that were...

... in the presence of serotonin, and secretion is completely abolished by cobalt. Perfusion with serotonin excites the salivary gland cells into impulse activity, and often evokes bursting. Impulse activity of the peripherally projecting, serotonergic Retzius cells evokes both depolarizations and action potentials...

... between 40 and 130μmoll −1 . These results indicate that Ca 2+ and other divalent cations compete for binding sites at the Ca-channel and thus determine excitability. Indirect effects due to changes of the surface potential are discussed. * Present address: Abteilung Pharmakologie der RWTH Aachen...