Experimental traces from an anaesthetized, neuromuscular-blocked and atenolol-pretreated rat illustrating the effects on BP, HR, IRNA and IPNA evoked by stimulation of chemoreceptor afferents with sodium cyanide (NaCN; 50 μg i.v.) before, and 10 and 30 min following SB-269970 (100 μg kg−1, i.c.).