Le Merrer J, Gavello-Baudy S, Galey D, Cazala P.

Centre de Neurosciences Integratives et Cognitives, Universites Bordeaux 1 et 2, UMR CNRS 5228, Avenue des Facultes, 33405 Talence, France.

Mice self-administer morphine into the lateral septum (LS), but the neuronal connections underlying this behaviour remain unknown. The present study tested whether the acquisition of intra-LS morphine self-administration depends on dopaminergic mechanisms. Mice were allowed to self-inject morphine (5 or 20ng/50nl) or vehicle directly into the LS using a spatial discrimination Y-maze task. Fos imaging was used to evaluate neuronal activation in cerebral structures directly connected to the LS or belonging to the dopaminergic system. The involvement of dopaminergic and opioidergic mechanisms was assessed by pre-treating naive mice peripherally with the D1 antagonist SCH23390, the D2/D3 antagonist sulpiride or the opiate antagonist naloxone before daily self-administration sessions. Mice acquired self-administration behaviour for intra-LS morphine that was associated with increased Fos expression in the ventral tegmental area (VTA), dorsal and ventral striatum and prefrontal cortex. Pre-treating animals with naloxone, SCH23390 or sulpiride completely prevented them from acquiring intra-LS morphine self-administration. All three antagonists consistently blocked Fos expression in the prefrontal cortex, but not in the VTA and striatum. Taken together, our results show that morphine self-administration into the LS depends on dopaminergic (D1 and D2/D3) and opioidergic mechanisms. Furthermore, they suggest that opioid peptides released in the LS could participate in regulating the activity of mesotegmental dopaminergic neurons.

PMID: 17467070 [PubMed – as supplied by publisher]

Evans S, Keenan TR, Shipton EA.

Department of Health and Social Care, University of Canterbury, New Zealand.

Aim: There is limited research examining the functioning of children living with parental chronic pain and illness. The aim of this study was to examine the psychosocial adjustment and physical health of children living with a mother experiencing chronic pain. Methods: One-hundred and three children aged 6-12 years served as participants, with approximately equal numbers of children in maternal chronic pain (n = 55) and control groups (n = 48). Children completed self-reports about their internalising behaviour, health and attachment security. Mothers, fathers and teachers completed questionnaires relating to children’s internalising and externalising behaviour, social behaviour and physical health. Results: Reports from children, mothers and fathers indicated significantly more internalising, externalising, insecure attachment and social and health problems for children in the maternal chronic pain group compared with control children. Teachers reported decreased social skills and increased pain complaints for children in the maternal chronic pain group. Boys in the maternal chronic pain group appear to be affected more than girls. Boys reported more anxiety and insecure attachment, while mothers reported greater social problems and increased illness behaviour for boys. Characteristics of the mother’s pain condition, such as, severity, length and frequency were generally unrelated to child functioning. Conclusions: The study demonstrates the importance of maternal and family variables to child outcomes. The results are discussed in terms of maternal chronic pain comprising a considerable, yet rarely studied, influence in the lives of young children.

PMID: 17444828 [PubMed – in process]