Fig. 4. Summary of NaCN-induced cardiovascular reflexes. Effects on ventral aortic pressure and heart rate after NaCN injections either externally into the respiratory water (A,C) or internally into the afferent branchial artery (B,D) in control and MK801-treated fish (MK801) (means + S.E.M.; N=7). Open bars show the pre-exposure values; grey bars, the maximal response to NaCN. *A statistically significantly difference (P<0.05) from pre-exposure values. For abbreviations, see Table 3.