Fig. 4: Dorsal CA1 neurons responded to corticosterone more strongly than ventral CA1 neurons.

A Representative sagittal section of brain showing GR immunoreactivity in dorsal (top) and ventral (bottom) hippocampi. Rectangle boxes depict the region of the slice used for quantification of optical density. B, C Quantification of GR protein expression from the perisomatic region to the distal dendritic region of CA1 from the dorsal and ventral hippocampi. D Western blot (top) and quantification (bottom) of GR protein in CA1 region from the dorsal and ventral hippocampi. E–Q We performed whole-cell current-clamp recordings. E, H Representative voltage responses with step current commands ranging from −150 pA to +30 pA (Δ = 20 pA) at RMP before and after bath application of corticosterone. Corticosterone lowered R_in (G) but had no impact on RMP (F) in dorsal CA1 neurons. There are no changes in RMP (I) and R_in (J) in ventral CA1 neurons following corticosterone treatment. Representative voltage responses with depolarizing current step (150 pA; 750 ms) at RMP in dorsal (K) and ventral (M) CA1 neurons. L Dorsal CA1 neurons had decreased action potential firing at RMP following corticosterone treatment. N Action potential firing at RMP was not altered in ventral CA1 neurons following corticosterone treatment. O Corticosterone doses of 10 nM, 100 nM, and 1 μM had no effect on RMP of CA1 neurons in dorsal and ventral hippocampi. 100 nM corticosterone significantly reduced R_in at RMP (P) and at −65 mV (Q) in dorsal CA1 neurons compared to 10 nM and 1 μM corticosterone. When compared to 10 nM and 1 μM corticosterone, 100 nM corticosterone had no impact on R_in at RMP (P) and at −65 mV (Q) in ventral CA1 neurons. Data are expressed as mean ± SEM.