Fig. 7.

There were differences among the rat strains in the density of K⁺ channel-ir neurons in the medullary raphé. Presented for both males and females is the average neuron density over all the sections 0–2 mm rostral to obex. In male rats the density of all 3 K⁺ channel-ir neurons was greater in (P < 0.05) in the SS males than in the other 2 male strains. In the female rats, there were also significant differences between strains in density of K⁺ channel-ir neurons with density least in the FHH strain. There were no significant (P > 0.10) strain differences in the density of Nissl-stained neurons.