Fig. 8. Effects of transmitter agonists and antagonists on L- and T-potentials. All recordings from Dipurena. (Aa) Effect of glutamate (50 mmol l^–1 sodium glutamate) on resting potential (continuous line) and amplitude of superimposed LT-potentials (circles and dotted line). Superfusion with glutamate-ASW as indicated. (Ab) Records of superimposed LT-potentials: (1) before, (2) during, (3) after the application of glutamate. (Ba) Effect of NS102 (5 µmol l^–1, with 0.025% DMSO), a blocker of kainate glutamate receptors, on the amplitude of superimposed LT-potentials of two nematocytes (filled circles and triangles). A third cell (control; open triangles) exposed to 0.025% DMSO only in ASW. Re-impaling the second cell (filled triangles) after wash-out of the blocker tested the reversibility of its action. (Bb) LT-potentials of the first cell recorded 20–32 min (data given below the records) after start of superfusion with NS102; recorded at the times indicated in Ba. The resting potential remained constant at –62 mV. (C) T-potentials recorded before (1), 5 min after the start (2), and 5 min after the end (3) of superfusion with mecamylamine (10 µmol l^–1). (D) T-potential recorded during superfusion with physostigmine (100 µmol l^–1). Prior to application of physostigmine, the amplitude of the hyperpolarizing component was 5 mV, analogue to C 1.