Sexual chemosignals detected by vomeronasal and olfactory systems mediate intersexual attraction in rodents, and act as a natural reinforcer to them. The mesolimbic pathway processes natural rewards, and the nucleus accumbens receives olfactory information via glutamatergic projections from the amygdala. Thus, the aim of this study was to investigate the involvement of the mesolimbic pathway in...

Previous research has shown that injection of morphine into the ventral tegmental area (VTA) facilitates the onset of maternal behavior in virgin female rats, and injection of the opioid antagonist naltrexone into the VTA disrupts the onset of maternal behavior in parturient rats. Placentophagia -- ingestion of placenta and amniotic fluid, usually at parturition -- modifies central opioid proce...

1 An assessment of the current role of naloxone in clinical toxicology has been made in a series of three separate epidemiological studies. 2 Through the National Poisons Information Service we found that the role of naloxone in opioid poisoning is often not appreciated by the enquirer and that toxicological screening is often requested before the diagnostic use of naloxone. 3 The recommended d...

Quaternary derivatives of naloxone and naltrexone, methyl naloxonium chloride(ORG 10908) and naltrexone methobromide ( MRZ 2663BR ), respectively, were compared with the parent compounds for their ability to antagonize the reinforcing properties of heroin as measured in an operant, i.v., self-administration paradigm. As expected, lower doses (up to 0.2 mg/kg) of naloxone and naltrexone produced...

Electric footshock elicited an immediate burst of activity followed by a period of immobility termed freezing. Naloxone, an opiate antagonist, enhanced both of these postshock reactions (Experiment 1). Naloxone's effects on the active and inactive components of the postshock reaction paralleled those of increasing shock intensity (Experiment 2). This finding suggests that the drug caused these ...

Compared with naloxone, two opiate antagonists (naltrexone and S-20682) were tested in the intact dog in order to reverse respiratory depression, induced by fentanyl 50 micrograms kg-1 i.v. Respiratory rate and arterial blood-gases were measured at 5, 30, 60, 120, 180 and 240 min after the additional i.v. injection of the antagonist (1 microgram kg-1). Only S-20682, but not naloxone or naltrexo...

We assessed the effects of naloxone, an opioid antagonist, on exercise capacity in 13 men and 5 women (mean age = 30.1 yr, range = 21-35 yr) during a 25 W/min incremental cycle ergometer test to exhaustion on different days during familiarization trial and then after 30 mg (iv bolus) of naloxone or placebo (Pl) in a double-blind, crossover design. Minute ventilation (Ve), O(2) consumption (Vo(2...

INTRODUCTION Naloxone, an opiate antagonist that can avert opiate overdose morality, has long been prescribed to drug users in Europe and in a few US cities. However, there has been little documented evidence of naloxone distribution programs and their feasibility in the peer reviewed literature in the US. METHODS A pilot overdose prevention and reversal program was implemented in a New York ...

Emotional distress is the most undesirable feature of painful experience. Numerous studies have demonstrated the important role of the limbic system in the affective-motivational component of pain. The purpose of this paper was to examine whether microinjection of nonsteroidal anti-inflammatory drugs (NSAIDs), Clodifen, Ketorolac, and Xefocam, into the dorsal hippocampus (DH) leads to the devel...

OBJECTIVE To document the incidence and outcomes of narcotic use during pregnancy in northwestern Ontario. DESIGN Three-year prospective cohort study. SETTING Sioux Lookout and surrounding communities in northwestern Ontario. PARTICIPANTS A total of 1206 consecutive births in a catchment area of 28 000 First Nations patients. MAIN OUTCOME MEASURES Incidence of narcotic use, and maternal...