LC activation by sciatic nerve stimulation (A) and carbachol (B) in sham-operated (solid bars) versus adrenalectomized (open bars) rats. A, The ordinate represents LC discharge rate (Hz). Bars represent the mean rate during the tonic and evoked components of the LC response to repeated sciatic nerve stimulation for 21 neurons of sham-operated and adrenalectomized rats. Vertical lines represent mean ± 1 SEM *p < 0.05, ttest for independent samples. B, The ordinate indicates the increase in LC discharge rate above the mean discharge rate determined over 9 min before carbachol (0.09 μg, i.c.v.) administration. Bars are the mean of eight rats in both sham-operated and adrenalectomized groups. Carbachol produced a similar increase in LC discharge rate in both groups of rats (ttest, independent samples). The mean LC discharge rates before carbachol administration were 1.6 ± 0.2 and 2.4 ± 0.4 Hz for sham-operated and adrenalectomized rats, respectively.