Kamishoyosan Alleviates Anxiety-like Behavior in a Premenstrual Syndrome Rat Model

Figure 1

Experimental timeline for progesterone withdrawal, drug treatments, and behavioral tests. Experiment 1: examination of the effect of KSS on anxiety-like behavior induced by progesterone withdrawal. Female rats received daily progesterone injections (i.p.) for 21 days. The EPM test was performed 48 h after the final progesterone injection. KSS was administered p.o. 60 min before the EPM test. Experiment 2: examination of the effect of the 5-HT_1A receptor agonist buspirone on anxiety-like behavior induced by progesterone withdrawal. Buspirone was administered i.p. 30 min before the EPM test. Experiment 3: evaluation of the involvement of 5-HT_1A receptors in the effect of KSS on anxiety-like behavior. The 5-HT_1A receptor antagonist WAY-100635 was coadministered i.p. with KSS 60 min before the EPM test. Experiment 4: assessment of the effect of KSS on the extracellular 5-HT concentration. The implantation of a guide cannula for microdialysis was conducted 5–7 days before the microdialysis procedure. At 48 h after the final progesterone injection, dialysis probes were inserted into the guide cannula, and brain microdialysis was performed. After collecting dialysate samples for baseline measurements, KSS was administered p.o. EPM, elevated plus maze; KSS, Kamishoyosan; p.o., per os; i.p., intraperitoneally; 5-HT, serotonin.