Fig. 4
From: The role of NMDA receptors in rat propofol self-administration
The X-axis represents the dose of MK-801(mg/kg). The Y-axis represents the number of responses in 1 h of sucrose self-administration. Black bars represent active nose-pokes, while gray bars represent inactive nose-pokes. MK-801 (0.1 or 0.2 mg/kg, ip) have no changes in the numbers of active or inactive nose-poke responses in rats sucrose self-administration, 0.4 mg/kg MK-801 dose exhibited a significant reduction in the number of active nose-poke responses (F (3, 20) = 20.8673, P < 0.01)