“…Alterations in striatal dopamine levels of female rats (n = 81) were measured for 5, 20 and 30 mg/kg of acute morphine injections (Maisonneuve, et al, 1991;Pearl, et al, 1996;Maisonneuve and Glick, 1999;Szumlinski, et al, 2000a;Steinmiller, et al, 2003;Velasquez, et al, 2019). Morphine at doses of 5 and 20 mg/kg increases dopamine levels in both regions nucleus accumbens (5 mg/kg: 194.29 AE 17.5%, 20 mg/kg: 212.5 AE 37.5%) and caudate putamen (5 mg/ kg: 160.0 AE 15.27%) with no significant differences between the regions (F 1,7 = 1.47, p = 0.26).…”