Fig. 4.

Effect of HAL 10 mg /L + ROP on light/dark-stimulatory response. In the HAL 10 mg/L + ROP 1 mg/L group, the response was enhanced in the first light condition compared to the CNTL; however, the response was significantly decreased in the second to sixth dark conditions (a). In the HAL 10 mg/L + ROP 5 mg/L group, the response significantly increased in all light conditions compared to the CNTL. However, the response significantly decreased in all dark conditions (b). In the HAL 10 mg/L + ROP 10 mg/L group, there was no significant difference in all dark conditions compared to the CNTL, but the response was enhanced from the first to fifth light conditions (c). The HAL 10 mg/L + ROP 1 mg/L group was significantly enhanced only in the first light condition compared with the HAL 10 mg/L group (d). The HAL 10 mg/L + ROP 5 mg/L group had a significantly enhanced response in all light conditions compared to the HAL 10 mg/L group (e). In the HAL 10 mg/L + ROP 10 mg/L group, the response was improved in all dark conditions, compared to the HAL 10 mg/L, whereas the response was enhanced in all light conditions (f). CNTL: Control, HAL 10: Haloperidol 10 mg/L, ROP 1, 5, 10: Ropinirole 1, 5, 10 mg/L, ON: light-on period, OFF: light-off period. Tukey–Kramer test; *p <0.05, **p <0.01 from the CNTL vs HAL 10 + ROP groups. All values are presented as means ± SEMs (n=128)