Figure 1.

Experimental setup. All rats were 8-week-old male Wistar rats weighing 250–300 g. After a 4-day adaptation period, the rats were randomly divided into experimental groups. Fecal samples were collected randomly from each cage on day 1 and day 20 of the experiment. Saline citalopram or oxytocin was given from day 7 to day 21 by subcutaneous administration and was injected at the same time every day (9:00–10:00 a.m.): (A) First experiment, multidrug environment. Stress was induced by non-invasive drinking water-mediated corticosterone administration for 21 days. (B) Second experiment, single drug environment.