Figure 6.

Spontaneous withdrawal following prenatal morphine (10 and 30 mg/kg) exposure affected tremor and vocalization behaviors in spiny mice pups. (a) Male pups on PND-1 from the 10 mg/kg morphine (N = 12) and 30 mg/kg morphine (N = 12) exposed groups experienced a significantly greater number of tremors compared to the saline-exposed controls (N = 8). Pups from the 30 mg/kg morphine exposed group (N = 12) experienced a significantly greater number of tremors compared to the 10 mg/kg morphine exposed group (N = 12) (AUC [#Tremors] – Saline: 0.13 $\pm$ 0.25; 10 mg/kg: 5.08 $\pm$ 3.30; 30 mg/kg: 3.79 $\pm$ 2.56). (b) Similarly, female pups on PND-1 from the 10 mg/kg morphine exposed group (N = 12) experienced a significantly greater number of tremors compared to the saline-exposed controls (N = 9) and 30 mg/kg morphine exposed group (N = 9) (AUC [#Tremors] – Saline: 0.11 $\pm$ 0.24; 10 mg/kg: 4.21 $\pm$ 3.25; 30 mg/kg: 1.30 $\pm$ 1.48). (c) Male pups on PND-2, 3 and 4 from the 10 mg/kg morphine (N = 12) and on PND-2, 4 and 5 from the 30 mg/kg morphine (N = 12) exposed groups emitted a significantly fewer ultrasonic vocalizations compared to the saline-exposed controls (N = 8) (AUC [#Vocalizations] – Saline: 706.4 $\pm$ 49.48; 10 mg/kg: 480.2 $\pm$ 55.63; 30 mg/kg: 509.7 $\pm$ 58.52). (d) Similarly, female pups on PND-1, 2, 3 and 4, from the 10 mg/kg morphine (N = 12) and PND-1, 2, 3 and 6 from the 30 mg/kg morphine exposed group (N = 9) emitted a significantly fewer ultrasonic ultrasonic vocalizations compared to the saline-exposed controls (N = 9). Additionally, on PND-1, 2, 3, 6 female pups from the 30 mg/kg morphine exposed group (N = 9) emitted a significantly fewer ultrasonic vocalizations compared to the 10 mg/kg morphine exposed group (N = 12) and saline-exposed controls (N = 9) (AUC [#Vocalizations] – Saline: 684.4 $\pm$ 46.99; 10 mg/kg: 513.7 $\pm$ 63.01; 30 mg/kg: 297.5 $\pm$ 48.76). Data are presented as means totals (±SEM) during the PND 0–7 period. An asterisk symbol (∗ = saline vs. 10 mg/kg morphine) or pound symbol (# = saline vs. 30 mg/kg morphine) or nabla symbol (∇ = 10 mg/kg morphine vs. 30 mg/kg morphine) are used to indicate a significant difference between groups, P < 0.05.