AN ELECTROPHYSIOLOGICAL EVALUATION OF SEROTONERGIC DORSAL RAPHE NEURONS IN MAUDSLEY RATS

Extracellular electrophysiological recording techniques were used to s tudy serotonergic dorsal raphe (DRN) neurons in Maudsley Reactive (MR) , Maudsley Non-Reactive (MNRA) and Sprague Dawley (SD; reference contr ol strain) rats. No significant differences were observed in the avera ge discharge rates of DRN neurons from SD, MR and MNRA rats. The sensi tivity of DRN neuron somatodendritic 5HT1(A), autoreceptors to the inh ibitory effects of i.v. 8-OH-DPAT or alpha(1),-adrenoceptors to the ex citatory effects of iontophoretic phenylephrine did not differ signifi cantly among strains. These findings are discussed in light of the pre viously reported strain-dependent differences in anxiety-like behavior and noradrenergic locus coeruleus neurons.