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Offspring of Prenatal IV Nicotine Exposure Exhibit Increased Sensitivity to the Reinforcing Effects of Methamphetamine.

Harrod SB, Lacy RT, Morgan AJ - Front Pharmacol (2012)

Bottom Line: Maternal smoking during pregnancy is associated with increased substance abuse in offspring.There were no sex differences in either experiment.These results indicate that IV PN-exposed adult offspring exhibited increased sensitivity to IV METH.

View Article: PubMed Central - PubMed

Affiliation: Behavioral Neuroscience Program, Department of Psychology, University of South Carolina Columbia, SC, USA.

ABSTRACT
Maternal smoking during pregnancy is associated with increased substance abuse in offspring. Preclinical research shows that in utero exposure to nicotine, the primary psychoactive compound in tobacco smoke, influences the neurodevelopment of reward systems and alters motivated behavior in offspring. The present study determined if prenatal nicotine (PN) exposure altered the sensitivity to the reinforcing and aversive effects of methamphetamine (METH) in offspring using a low dose, intravenous (IV) exposure method. Pregnant dams were administered nicotine (0.05 mg/kg/injection) or prenatal saline (PS) 3×/day on gestational days 8-21, and adult offspring were tested using METH self-administration (experiment 1) or METH-induced conditioned taste aversion (CTA; experiment 2) procedures. For METH self-administration, animals were trained to respond for IV METH (0.05 mg/kg/infusion; fixed-ratio 3) and they were tested on varying doses of the reinforcer (0.0005-1.0 mg/kg/infusion). For METH CTA, rats received three saccharin and METH pairings (0, 0.3, or 0.5 mg/kg, sc) followed by 14 daily extinction trials. Experiment 1: PN and PS animals exhibited inverted U-shaped dose-response curves; however, the PN animal's curve was shifted to the left, suggesting PN animals were more sensitive to the reinforcing effects of METH. Experiment 2: METH CTA was acquired in a dose-dependent manner and the factor of PN exposure was not related to the acquisition or extinction of METH-induced CTA. There were no sex differences in either experiment. These results indicate that IV PN-exposed adult offspring exhibited increased sensitivity to IV METH. This suggests that PN exposure, via maternal smoking, will alter the reinforcing effects of METH during later stages of development, and furthermore, will influence substance use vulnerability in adult human offspring.

No MeSH data available.


Related in: MedlinePlus

Mean (±SEM) preference scores for the 14 consecutive two-bottle extinction tests are presented for the PS and PN animals that were treated with either SAL or 0.3 mg/kg METH (A) or SAL or 0.56 mg/kg METH (B). Scores above 0.5 indicate a preference for saccharin and scores below 0.5 indicate a preference for water. There were no significant effects or interactions with the factor of Prenatal Treatment or Sex. Significant differences between days 1 and 14 are indicated by * (p < 0.001). Significant differences between SAL and the 0.3- and 0.56-mg/kg METH groups are indicated by ^ (p < 0.05) and ^^ (p < 0.001).
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Figure 4: Mean (±SEM) preference scores for the 14 consecutive two-bottle extinction tests are presented for the PS and PN animals that were treated with either SAL or 0.3 mg/kg METH (A) or SAL or 0.56 mg/kg METH (B). Scores above 0.5 indicate a preference for saccharin and scores below 0.5 indicate a preference for water. There were no significant effects or interactions with the factor of Prenatal Treatment or Sex. Significant differences between days 1 and 14 are indicated by * (p < 0.001). Significant differences between SAL and the 0.3- and 0.56-mg/kg METH groups are indicated by ^ (p < 0.05) and ^^ (p < 0.001).

Mentions: A 2 × 2 × 3 × 14 mixed-factorial ANOVA was conducted on the extinction data. There were no significant main effects or interactions with the factors of Sex or Prenatal Treatment. Figure 4 shows the saccharin preference data for the PN and PS groups injected with SAL or METH 0.3 or 0.56 mg/kg US as a function of extinction trials. The PN and PS groups represent both males and females; however, the factors of Prenatal Treatment are represented on Figure 4 because prenatal treatment was the focus of the study. Scores above 0.5 indicate a preference for saccharin, whereas scores below 0.5 indicate a preference for water.


Offspring of Prenatal IV Nicotine Exposure Exhibit Increased Sensitivity to the Reinforcing Effects of Methamphetamine.

Harrod SB, Lacy RT, Morgan AJ - Front Pharmacol (2012)

Mean (±SEM) preference scores for the 14 consecutive two-bottle extinction tests are presented for the PS and PN animals that were treated with either SAL or 0.3 mg/kg METH (A) or SAL or 0.56 mg/kg METH (B). Scores above 0.5 indicate a preference for saccharin and scores below 0.5 indicate a preference for water. There were no significant effects or interactions with the factor of Prenatal Treatment or Sex. Significant differences between days 1 and 14 are indicated by * (p < 0.001). Significant differences between SAL and the 0.3- and 0.56-mg/kg METH groups are indicated by ^ (p < 0.05) and ^^ (p < 0.001).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3376423&req=5

Figure 4: Mean (±SEM) preference scores for the 14 consecutive two-bottle extinction tests are presented for the PS and PN animals that were treated with either SAL or 0.3 mg/kg METH (A) or SAL or 0.56 mg/kg METH (B). Scores above 0.5 indicate a preference for saccharin and scores below 0.5 indicate a preference for water. There were no significant effects or interactions with the factor of Prenatal Treatment or Sex. Significant differences between days 1 and 14 are indicated by * (p < 0.001). Significant differences between SAL and the 0.3- and 0.56-mg/kg METH groups are indicated by ^ (p < 0.05) and ^^ (p < 0.001).
Mentions: A 2 × 2 × 3 × 14 mixed-factorial ANOVA was conducted on the extinction data. There were no significant main effects or interactions with the factors of Sex or Prenatal Treatment. Figure 4 shows the saccharin preference data for the PN and PS groups injected with SAL or METH 0.3 or 0.56 mg/kg US as a function of extinction trials. The PN and PS groups represent both males and females; however, the factors of Prenatal Treatment are represented on Figure 4 because prenatal treatment was the focus of the study. Scores above 0.5 indicate a preference for saccharin, whereas scores below 0.5 indicate a preference for water.

Bottom Line: Maternal smoking during pregnancy is associated with increased substance abuse in offspring.There were no sex differences in either experiment.These results indicate that IV PN-exposed adult offspring exhibited increased sensitivity to IV METH.

View Article: PubMed Central - PubMed

Affiliation: Behavioral Neuroscience Program, Department of Psychology, University of South Carolina Columbia, SC, USA.

ABSTRACT
Maternal smoking during pregnancy is associated with increased substance abuse in offspring. Preclinical research shows that in utero exposure to nicotine, the primary psychoactive compound in tobacco smoke, influences the neurodevelopment of reward systems and alters motivated behavior in offspring. The present study determined if prenatal nicotine (PN) exposure altered the sensitivity to the reinforcing and aversive effects of methamphetamine (METH) in offspring using a low dose, intravenous (IV) exposure method. Pregnant dams were administered nicotine (0.05 mg/kg/injection) or prenatal saline (PS) 3×/day on gestational days 8-21, and adult offspring were tested using METH self-administration (experiment 1) or METH-induced conditioned taste aversion (CTA; experiment 2) procedures. For METH self-administration, animals were trained to respond for IV METH (0.05 mg/kg/infusion; fixed-ratio 3) and they were tested on varying doses of the reinforcer (0.0005-1.0 mg/kg/infusion). For METH CTA, rats received three saccharin and METH pairings (0, 0.3, or 0.5 mg/kg, sc) followed by 14 daily extinction trials. Experiment 1: PN and PS animals exhibited inverted U-shaped dose-response curves; however, the PN animal's curve was shifted to the left, suggesting PN animals were more sensitive to the reinforcing effects of METH. Experiment 2: METH CTA was acquired in a dose-dependent manner and the factor of PN exposure was not related to the acquisition or extinction of METH-induced CTA. There were no sex differences in either experiment. These results indicate that IV PN-exposed adult offspring exhibited increased sensitivity to IV METH. This suggests that PN exposure, via maternal smoking, will alter the reinforcing effects of METH during later stages of development, and furthermore, will influence substance use vulnerability in adult human offspring.

No MeSH data available.


Related in: MedlinePlus