Fig. 4.

Effect of ANG II on the neuronal responsiveness to GBR agonist baclofen in neuronal cultures. A: representative tracing showing neuronal spontaneous action potentials (APs) recorded from a PBS-treated neuron under basal conditions (CON) and during superfusion of baclofen (BCF, 1 μM). APs were recorded from an AT₁R-positive neuron identified by single-cell RT-PCR. B: representative tracing showing APs recorded from an ANG II-treated neuron under basal conditions (CON) and during superfusion of baclofen. APs were recorded from an AT₁R-positive neuron by the same methods as in A. Ethidium bromide-stained gels seen in A and B show the PCR DNA products that correspond to AT₁R mRNA obtained from the same neuron after the electrophysiological recordings (lanes 2). The RNA from the whole dishes of neurons was used as positive control (lanes 1). M, marker. C: effect of baclofen (1 μM) on neuronal firing in AT₁R-positive neurons pretreated with ANG II or PBS control. Data are means ± SE (n = 7). D: dose-dependent inhibition induced by baclofen on neuronal firing in AT₁R-positive neurons pretreated with ANG II or PBS control. *P < 0.05 compared with respective control recording; #P < 0.05 compared with PBS treatment.