Jannike Mørch Andersen

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We investigated the relative importance of heroin and its metabolites in eliciting a behavioral response in mice by studying the relationship between concentrations of heroin, 6-monoacetylmorphine (6MAM), and morphine in brain tissue and the effects on locomotor activity. Low doses (subcutaneous) of heroin (< or =5 micromol/kg) or 6MAM (< or =15(More)
The aim of the present work was to use a three-choice simultaneous brightness discrimination test to examine the retention of non-spatial reference memory in rats treated with scopolamine (0.5 mg/kg) alone and in combination with various concentrations of D-cycloserine (DCS) (5, 15 and 50 mg/kg). Scopolamine given 1 h before testing for retention was found(More)
Methadone is a synthetic opiate that is useful in a variety of clinical settings, including in maintenance therapy of heroin dependence and as an analgesic. However, methadone can have negative effects on cognition in humans and in rodents. The mechanisms underlying methadone-induced disruption in cognition are unknown. One possibility is that methadone(More)
In this paper we show that exposure of a rat brain synaptosome fraction to the amyloid beta peptide fragment betaA(25-35), but not the inverted peptide betaA(35-25), stimulated production of reactive oxygen species (ROS) in a concentration- and time-dependent manner. The ROS formation was attenuated by the tyrosine kinase inhibitor genistein, the(More)
It has been demonstrated that a triple regimen consisting of procyclidine (6 mg/kg), diazepam (10 mg/kg) and pentobarbital (30 mg/kg) can effectively terminate soman-induced (1 x LD50) seizures/convulsions in rats when administered 30-40 min following onset. However, convulsive activity lasting for only 45 min can result in marked neuronal pathology. The(More)
High blood-brain permeability and effective delivery of morphine to the brain have been considered as explanations for the high potency of heroin. Results from Andersen et al. indicate that 6-monoacetylmorphine (6-MAM), and not morphine, is the active metabolite responsible for the acute effects observed for heroin. Here, we use pharmacokinetic modeling on(More)
This study was undertaken to develop techniques for measuring absolute rates of sterol synthesis in extrahepatic tissues in vitro and to estimate the magnitude of the errors inherent in the use of various 14C-labeled substrates for such measurements. Initial studies showed that significant errors were introduced when rates of synthesis were estimated using(More)
OBJECTIVES To reveal a possible relationship between a previously reported impairment of novelty seeking in rats exposed to methadone and changes in intracellular molecules related to learning and memory. METHODS Expression of phosphorylated Ca²⁺-calmodulin kinase II (pCaMKII), extracellular-signal-regulated kinase 2 (pERK2) and cAMP-responsive element(More)
Behavioral consequences of long-term methadone treatment have received little attention either in humans or experimental animals. In this work, we show that methadone (2.5-10 mg/kg) administered (sc) once daily for three weeks with repeated withdrawal on Saturday and Sunday impairs the novelty preference in rats. One hour after the last injection, when(More)
Results from lesion studies show that selective damage to the temporal cortex or lateral entorhinal cortex impairs visual memory, whereas damage to the hippocampal region does not affect retention of a visual discrimination task. Major input pathways of the above structures use glutamate as neurotransmitter. The glutamate NMDA receptor appears to play an(More)