The development of a conditioned place preference to morphine: effects of lesions of various CNS sites (Olmstead 1997)
- The three compartment CPP apparatus was made of Acrylic.
- Two of the compartments were identical in size (45 X 45 X 30 cm)
- One had White walls with smooth floor.
- The other had black walls and wire mesh floor.
- The third compartment was an unpainted tunnel (36 X 18 X 20 cm).