An electrophysiological evaluation of serotonergic dorsal raphe neurons in Maudsley rats

Extracellular electrophysiological recording techniques were used to study serotonergic dorsal raphe (DRN) neurons in Maudsley Reactive (MR), Maudsley Non-Reactive (MNRA) and Sprague Dawley (SD; reference control strain) rats. No significant differences were observed in the average discharge rates of DRN neurons from SD, MR AND MNRA rats. The sensitivity of DRN neuron somatodendritic 5-HT1A autoreceptors to the inhibitory effects of i.v. 8-OH-DPAT or alpha 1-adrenoceptors to the excitatory effects of iontophoretic phenylephrine did not differ significantly among strains. These findings are discussed in light of the previously reported strain-dependent differences in anxiety-like behavior and noradrenergic locus coeruleus neurons.