Ketamine Administration Reverses Corticosterone-Induced Alterations in Excitatory and Inhibitory Transmission in the Rat Dorsal Raphe Nucleus

Figure 1

Repeated corticosterone and single ketamine injections do not influence basic membrane properties and excitability of DRN projection neurons. (a₁) Response of a representative putative serotonergic neuron to a depolarizing current pulse and (a₂) a single action potential of this cell at an extended timescale, with the “notch” on the descending phase marked with an asterisk. (b₁) Response of a putative GABAergic interneuron to a depolarizing current pulse and (b₂) a single action potential shown at an extended timescale. (c) Responses of a projection neuron to depolarizing current steps of increasing intensity (step: 20 pA; every second response and current pulse are shown) recorded in a DRN slice prepared from a control (Tween+NaCl) animal. (d) Relationship between spiking rate and injected current for the cell shown in (e). The slope of the linear regression line fitted to the experimental data represents the gain. (c) Summary graph showing mean gain (±SEM) of all neurons from the Tween+NaCl, Tween+Ket, Cort+NaCl, and Cort+Ket groups. The differences between groups are not significant.