Mean values of hippocampal extracellular concentrations of 5-HT (A), 5-HIAA (B), and dialysate corticosterone (D), and of behavioral activity scores (C) for the period after the intraperitoneal injection of saline or LPS in long-term intracerebroventricularly vehicle- and CRH-treated rats as deducted from the time curves presented in Figures 4, 6, and 7. Rats were treated in four experimental groups: intracerebroventricular vehicle/intraperitoneal saline, intracerebroventricular vehicle/intraperitoneal LPS, intracerebroventricular CRH/intraperitoneal saline, and intracerebroventricular CRH/intraperitoneal LPS. Samples were collected every 30 min as described under Protocol B. Extracellular levels of 5-HT and 5-HIAA are expressed as % of baseline, dialysate corticosterone as μg/dl, and behavioral activity scores as arbitrary units (for more details see Materials and Methods). *, Significantly different from intracerebroventricularly vehicle-/intraperitoneally saline-treated rats; +, significantly different from intracerebroventricularly CRH-/intraperitoneally saline-treated rats; #, significantly different from intracerebroventricularly vehicle-/intraperitoneally LPS-treated rats (Duncan multiple range test).