The proportion of isolated rat dorsal root ganglion neurones responding to bradykinin increases with time in culture

The proportion of isolated rodent dorsal root ganglion neurones expressing bradykinin receptors increases transiently with time in culture. However, it has not yet been investigated whether these receptors are functioning. Therefore the responses of these neurones to bradykinin (1 microM) were investigated in patch-clamp experiments in the current clamp mode after 0.8 and 1.8 days under culture conditions. The proportion of neurones responding to bradykinin was 26% (5/19) at day 0.8 and increased to 73% (16/22) at day 1.8. The intensity of the response was assessed by counting the number of action potentials evoked by bradykinin within four fixed intervals of 500 ms duration during each experiment. It increased with time in culture from an average of 8 +/- 2 (SD) at day 0.8 to 16 +/- 6 at day 1.8, respectively. These results provide evidence for the induction of functioning bradykinin receptors in cultured dorsal root ganglion neurones with time in culture.