Université de Fribourg

Regulation of MiR-124, Let-7d, and MiR-181a in the accumbens affects the expression, extinction, and reinstatement of cocaine-induced conditioned place preference

Chandrasekar, Vijay ; Dreyer, Jean-Luc

In: Neuropsychopharmacology, 2011, vol. 36, p. 1149-1164

Molecular adaptations underlying drug seeking and relapse remain largely unknown. Studies highlight post-transcriptional modifications mediated by microRNAs (miRNAs) in addiction and other neurological disorders. We have previously shown that chronic cocaine suppresses miR-124 and let-7d and induces the expression of miR-181a in mesolimbic pathway. To further address the role and target gene...

Université de Fribourg

The circadian clock, reward, and memory

Albrecht, Urs

In: Frontiers in Molecular Neuroscience, 2011, vol. 4, no. 41, p. -

During our daily activities, we experience variations in our cognitive performance, which is often accompanied by cravings for small rewards, such as consuming coffee or chocolate. This indicates that the time of day, cognitive performance, and reward may be related to one another. This review will summarize data that describe the influence of the circadian clock on addiction and mood-related...

Université de Fribourg

The brain-specific neural zinc finger transcription factor 2b (NZF-2b/7ZFMyt1) suppresses cocaine self-administration in rats

Chandrasekar, Vijay ; Dreyer, Jean-Luc

In: Frontiers in Behavioral Neuroscience, 2010, vol. 4, no. 14, p. -

Brain-specific neural-zinc-finger transcription factor-2b (NZF2b/7ZFMyt1) is induced in the mesolimbic dopaminergic region after chronic cocaine exposure and lentiviral-mediated expression of NZF2b/7ZFMyt1 in the nucleus accumbens results in decreased locomotor activity (Chandrasekar and Dreyer, 2010). In this study the role of NZF2b/7ZFMyt1 in active cocaine seeking and of its interaction with...

Université de Fribourg

Overexpression of plasminogen activators in the nucleus accumbens enhances cocaine-, amphetamine- and morphine-induced reward and behavioral sensitization

Bahi, Amine ; Dreyer, Jean-Luc

In: Genes, Brain and Behavior, 2008, vol. 7, no. 2, p. 244 - 256

Urokinase-type plasminogen activator (uPA) and tissue-type plasminogen activator (tPA) are extracellular proteases that play a role in synaptic plasticity and remodeling. Psychostimulants induce both tPA and uPA in acute and chronic drug delivery, but cocaine induces preferentially uPA, whereas morphine and amphetamine induce preferentially tPA. Specific doxycline-regulatable lentiviruses...

Université de Fribourg

The role of gamma-synuclein in cocaine-induced behaviour in rats

Boyer, Frederic ; Dreyer, Jean-Luc

In: European Journal of Neuroscience, 2008, vol. 27, no. 11, p. 2938 - 2951

The aim of this study was to investigate the role of γ-synuclein in the rewarding effects of chronic cocaine administration and its putative interaction with the dopamine transporter (DAT). For this purpose, regulatable lentiviruses driving overexpression of the rat γ-synuclein or DAT have been prepared, as well as lentiviruses expressing siRNAs, aimed at silencing either DAT or γ-synuclein...

Université de Fribourg

Role of accumbens BDNF and TrkB in cocaine-induced psychomotor sensitization, conditioned-place preference, and reinstatement in rats

Bahi, Amine ; Boyer, Frederic ; Vijay, Chandrasekar ; Dreyer, Jean-Luc

In: Psychopharmacology, 2008, vol. 199, no. 2, p. 169-182

Background Brain-derived neurotrophic factor (BDNF) is involved in the survival and function of midbrain DA neurons. BDNF action is mediated by the TrkB receptor–tyrosine kinase, and both BDNF and TrkB transcripts are widely expressed in the rat mesolimbic pathway, including the nucleus accumbens (NAc) and the ventral tegmentum area (VTA). Objective BDNF was previously shown to be involved in...

Université de Fribourg

Alpha-synuclein in the nucleus accumbens induces changes in cocaine behaviour in rats

Boyer, Frederic ; Dreyer, Jean-Luc

In: European Journal of Neuroscience, 2007, vol. 26, no. 10, p. 2764-2776

The mesolimbic dopaminergic system is widely recognized to be critical to the neurobiology of cocaine reward and addiction. The neuronal protein, α-synuclein, is an important regulator in dopaminergic transmission. It interacts with the dopamine transporter, and regulates dopaminergic content, neurotransmission and synaptic strength of dopaminergic neurons. Alpha-synuclein levels are elevated in...

Université de Fribourg

Silencing urokinase in the ventral tegmental area in vivo induces changes in cocaine-induced hyperlocomotion

Bahi, Amine ; Boyer, Frederic ; Kafri, Tal ; Dreyer, Jean-Luc

In: Journal of Neurochemistry, 2006, vol. 98, no. 5, p. 1619–1631

Serine proteases in the nervous system have functional roles in neural plasticity. Among them, urokinase-type plasminogen activator (uPA) exerts a variety of functions during development, and is involved in learning and memory. Furthermore, psychostimulants strongly induce uPA expression in the mesolimbic dopaminergic pathway. In this study, doxycycline-regulatable lentiviruses expressing either...

Université de Fribourg

The opioid fentanyl affects light input, electrical activity and Per gene expression in the hamster suprachiasmatic nuclei

Vansteensel, Mariska J. ; Magnone, Maria Chiara ; Oosterhout, Floor van ; Baeriswyl, Stéphanie ; Albrecht, Urs ; Albus, Henk ; Dahan, Albert ; Meijer, Johanna H.

In: European Journal of Neuroscience, 2005, vol. 21(11), p. 2958

The suprachiasmatic nuclei (SCN) contain a major circadian pacemaker, which is regulated by photic and nonphotic stimuli. Although enkephalins are present in the SCN, their role in phase regulation of the pacemaker is largely unknown. The opioid agonist fentanyl, a homologue of morphine, is an addictive drug that induces phase shifts of circadian rhythms in hamsters. We observed that these phase...