Neuronal reorganization in adult rats neonatally exposed to (±)-3,4-methylenedioxymethamphetamine.

The abuse of methylenedioxymethamphetamine (MDMA) during pregnancy is of concern. MDMA treatment of rats during a period of brain growth analogous to late human gestation leads to neurochemical and behavioral changes. MDMA from postnatal day (P)11-20 in rats produces reductions in serotonin and deficits in spatial and route-based navigation. In this experiment we examined the impact of MDMA from P11-20 (20 mg/kg twice daily, 8 h apart) on neuronal architecture. Golgi impregnated sections showed significant changes. In the nucleus accumbens, the dendrites were shorter with fewer spines, whereas in the dentate gyrus the dendritic length was decreased but with more spines, and for the entorhinal cortex, reductions in basilar and apical dendritic lengths in MDMA animals compared with saline animals were seen. The data show that neuronal cytoarchitectural changes are long-lasting following developmental MDMA exposure and are in regions consistent with the learning and memory deficits observed in such animals.

Evaluating a measure of tanning abuse and dependence.

OBJECTIVE: To evaluate the Structured Interview for Tanning Abuse and Dependence (SITAD). DESIGN: Longitudinal survey. SETTING: College campus. PARTICIPANTS: A total of 296 adults. MAIN OUTCOME MEASURES: The SITAD modified items from the Structured Clinical Interview for DSM-IV Axis I Disorders that focus on opiate abuse and dependence. Indoor tanning (IT) behavioral patterns and opiate-like reactions to tanning were measured, and IT behavior was measured 6 months later. RESULTS: Of 296 participants, 32 (10.8%) met the SITAD criteria for tanning abuse (maladaptive pattern of tanning as manifested by failure to fulfill role obligations, physically hazardous tanning, legal problems, or persistent social or interpersonal problems) and 16 (5.4%) for tanning dependence as defined by 3 or more of the following: loss of control, cut down, time, social problems, physical or psychological problems, tolerance, and withdrawal. The IT frequency in dependent tanners was more than 10 times the rate in participants who do not meet the SITAD criteria for tanning abuse or dependence. Tanning-dependent participants were more likely to report being regular tanners (75%; odds ratio, 7.0). Dependent tanners scored higher on the opiate-like reactions to tanning scale than did abuse tanners, who scored higher than those with no diagnosis. CONCLUSIONS: The SITAD demonstrated some evidence of validity, with tanning-dependent participants reporting regular IT, higher IT frequency, and higher scores on an opiate-like reactions to tanning scale. A valid tanning dependence screening tool is essential for researchers and physicians as a tanning-dependent diagnosis may facilitate a better understanding of tanning motivations and aid in the development of efficacious intervention programs.

Nicotine sensitization in adult male and female rats quinpirole-primed as neonates.

RATIONALE: Increases in dopamine D2-like receptor function are common in several psychological disorders that demonstrate a four to five fold increase in nicotine abuse compared to the general population. OBJECTIVE: The objective of this study was to analyze the interaction of sex differences and sensitization to nicotine in rats D2 receptor primed as neonates. MATERIALS AND METHODS: A total of 32 male and 32 female Sprague-Dawley rats derived from eight litters were ontogenetically treated with quinpirole (1 mg/kg) or saline from postnatal days (P) 1-21 and raised to adulthood. At P60, all animals were given an acute injection of quinpirole HCl (100 microg/kg) and yawns were counted for 1 h. Yawning has been shown to be a behavioral event mediated by D2-like receptors. Beginning on P61-65, animals were habituated to a locomotor arena and subsequently administered either nicotine (0.5 mg/kg free base) or saline (intraperitoneal) every second day for 3 weeks. Approximately 15 min after each injection, animals were placed into the arena and horizontal activity and vertical rears were recorded. RESULTS: A robust increase of yawning was observed at P60 in D2 primed as compared to saline controls. Priming of D2-like receptors increased the locomotor response to nicotine in horizontal activity in both males and females, but females demonstrated a more robust hypoactive locomotor response to initial nicotine treatment when compared to saline-treated females. Nicotine also produced a significant decrease of vertical rearing in both males and females. CONCLUSIONS: It appears that D2 receptor priming enhances sensitization to nicotine in adult rats, and females may be more behaviorally sensitive to nicotine than males.