Fig. 4. T-potentials in nematocytes of Stauridiosarsia (A–C,F–H), Coryne (D) and Dipurena (E). Membrane voltage (upper traces) and probe excursion (lower traces) as in Fig. 2. (A) T-potentials induced by contacts of the probe with an area of the tentacle distant from nematocytes; the first response of Aa is enlarged in Ab. (B) A hyper-/re-polarizing component was observable at depolarizing membrane voltage. (C–E) Representative waveforms of T-potentials recorded from nematocytes of Stauridiosarsia (C), Coryne (D), and Dipurena (E). E 2 shows the superposition of L- and T-potentials, typically occurring in Dipurena upon mechanical stimulation of nematocytes or, here, pulling at the stinging thread of a discharged nematocyst. (F 1,2) Series of T-potentials following an L-potential that was induced by a discharge-triggering stimulation of a distant nematocyte; F 2 is a section of the same `tail' of T-potentials, recorded 1 min after F 1. (G) Time course of amplitude and instantaneous frequency of the series of T-potentials illustrated in F. (H) Mean (± s.d.) of the hyperpolarizing component of T-potentials as a function of the instantaneous frequency of preceding T-potentials (intervals averaging 20 s; N=number of trials).