ABSTRACT
Accumulating evidence indicates that the neuropeptide oxytocin (OXY) may modulate reward-related behavioural responses to methamphetamine (METH) administration. Limited research has examined the effect of OXY on METH-induced conditioned place preference (CPP) and little is known about the neural mechanisms involved. A Fos immunohistochemistry study recently demonstrated that peripheral OXY administration reduced METH-induced Fos expression within the nucleus accumbens (NAc) core and subthalamic nucleus (STh) in rats. The current study aimed to (i) investigate the effect of systemically administered OXY on METH-induced CPP, (ii) determine the effectiveness of a single-trial CPP procedure with METH, in order to (iii) evaluate whether pretreatment with OXY injected directly into the NAc core or the STh attenuates METH-induced CPP. Results showed that male Sprague Dawley rats learned to associate unique compartmental cues with METH (1 mg/kg, i.p.) such that they spent more time in the METH-paired compartment and less time in the saline-paired compartment. Pretreatment with systemic OXY (0.6 mg, i.p.), or OXY (0.6 ng, i.c.) microinjected into the NAc core or the STh prior to METH administration attenuated the formation of a CPP to METH. This provides further evidence that OXY acts within either the NAc core or the STh to reduce the rewarding effects of METH administration.
Subject(s)
Conditioning, Psychological/physiology , Methamphetamine/antagonists & inhibitors , Nucleus Accumbens/physiology , Oxytocin/physiology , Subthalamic Nucleus/physiology , Animals , Choice Behavior/drug effects , Choice Behavior/physiology , Conditioning, Psychological/drug effects , Injections, Intraperitoneal , Male , Methamphetamine/pharmacology , Microinjections/methods , Microinjections/psychology , Nucleus Accumbens/drug effects , Oxytocin/administration & dosage , Oxytocin/pharmacology , Rats , Rats, Sprague-Dawley , Reward , Subthalamic Nucleus/drug effectsABSTRACT
Several lines of evidence support the involvement of serotonergic (5-HT) neurons of the median raphe nucleus (MRN) in anxiety-like behaviour. In this context, it is known that blockade of 5-HT(1A) somatodendritic autoreceptors in the midbrain raphe nuclei increases the firing rate of these neurons, disinhibiting 5-HT release in postsynaptic target areas such as amygdala, hippocampus and periaqueductal grey matter (PAG). However, while activation of 5-HT(1A) or 5-HT(2) receptors in forebrain targets such as the amygdala or hippocampus enhances anxiety-like behaviours in rodents, stimulation of both receptor subtypes in the midbrain PAG markedly reduces anxiety-like behaviour. In view of these findings, the present study investigated whether the anti-anxiety effects induced by pharmacological disinhibition of 5-HT neurons in the MRN are attenuated by the blockade of 5-HT(2) receptors within the PAG. Mice received combined intra-PAG injection with ketanserin (10 nmol/0.1 µl), a 5-HT(2) receptor antagonist, followed by intra-MRN injection of WAY-100635 (5.6 nmol/0.1 µl), a highly selective 5-HT(1A) receptor antagonist. They were then individually exposed to the elevated plus-maze (EPM), with the videotaped behavioural sessions subsequently scored for both conventional and ethological measures. The results confirmed that intra-MRN infusion of WAY100635 reduces behavioural indices of anxiety without significantly altering general activity measures, and further showed that this effect was completely blocked by intra-PAG pretreatment with an intrinsically-inactive dose of ketanserin. Together, these results suggest that 5HT(2) receptor populations located within the midbrain PAG play a significant role in the reduction of anxiety observed following disinhibition of 5-HT neurons in the MRN.
Subject(s)
Anti-Anxiety Agents/pharmacology , Ketanserin/pharmacology , Periaqueductal Gray/drug effects , Piperazines/pharmacology , Pyridines/pharmacology , Raphe Nuclei/drug effects , Serotonin Antagonists/pharmacology , Animals , Anti-Anxiety Agents/antagonists & inhibitors , Behavior, Animal/drug effects , Ketanserin/administration & dosage , Male , Maze Learning/drug effects , Mice , Microinjections/psychology , Piperazines/administration & dosage , Pyridines/administration & dosage , Serotonin Antagonists/administration & dosageABSTRACT
The aim of the study was to assess the psychological repercussions of IVF + ICSI on the male partner of infertile couples and on the couples and on the couple itself. The preliminary work has been done on the 23 couples in the waiting list of an ICSI cycle in A. Beclere hospital in Clamart. All couples respond to the same questionnaire. The two members of the couples were present in a semi-structured interview by 2 clinical psychologists. This ICSI scheme requires a complete change about the biological paternity. For infertile men, getting embryos work as a real reparation of their wounded ego, and the guilt goes from the man to the women when embryos are obtained. This study shows that infertile couples involved in IVF + ICSI have not the same concerns that doctors. Genetic abnormality transmission is not mentioned. On the opposite the male patients are strongly concerned by obtention of embryos which restore their fertility power. At this stage, female patients have to prove by carry out a pregnancy that they are as "good" as their partner.