Fig. 10. Octopamine reduced the resistance of the preparation in a dose-dependent
manner. (A) For resistance measurements, 10 subsequent pulses of negative
current were applied. When compared with the averaged voltage response
(
V) before drug injection (left), an injection of 150nmol of
octopamine decreased the response (right). (B) The normalized resistance
Rafter/Rbefore was computed. While
control injections of haemolymph Ringer (HLR) did not alter the resistance of
the preparation, octopamine (OA) reduced it in a dose-dependent manner.
Serotonin (5-HT), however, had no effect. Values are means + S.E.M. The
asterisk indicates a significant difference from the control
(P<0.02, Student's t-test).
