Table 2. Anxiety and locomotor activity assessment during the NORT in wild-type and R6/1 mice treated with vehicle or sildenafil.

	Group	Day 1	Day 2	Day 3	Training trial	Testing trial
Defecations	WT vehicle	3.24±0.72	3.10±0.84	2.00±0.22	3.10±1.52	2.32±0.24
	R6/1 vehicle	2.99±2.21	3.40±0.74	3.2±1.33	2.22±0.99	3.11±1.32
	WT sildenafil	3.31±2.10	4.72±0.97	4.2±1.49	3.23±1.08	2.76±1.33
	R6/1 sildenafil	3.00±0.22	3.92±0.41	4.0±0.33	3.69±1.51	3.22±1.40
Time in center (%)	WT vehicle	29.55±2.69	31.17±5.12	31.23±7.55	13.32±4.27	19.31±2.88
	R6/1 vehicle	41.01±7.55	26.41±9.38	33.92±7.66	15.88±5.77	15.65±7.99
	WT sildenafil	32.23±2.22	24.04±6.22	28.55±3.05	14.23±8.11	22.25±6.36
	R6/1 sildenafil	35.75±9.33	25.94±6.81	27.44±6.45	16.55±5.97	25.44±4.54
Distance traveled (cm)	WT vehicle	4525±323	3775±393	3444±252	2223±363	1923±222
	R6/1 vehicle	3800±298	3383±303	2955±422	2099±525	1714±193
	WT sildenafil	4350±234	3815±412	3221±331	3012±495	2013±432
	R6/1 sildenafil	4185±334	3292±368	2978±522	2168±356	1982±297

The number of defecations, time spent in the center of the open field and the distance traveled were analyzed during the NORT in wild-type (WT) and R6/1 mice treated with vehicle or sildenafil (3 mg/Kg) immediately after training. Day 1-3 correspond to habituation. Values are shown as mean ± SEM. For each parameter data were analyzed by two-way ANOVA.