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

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

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 tissue-type plasminogen activator system in amphetamine-induced conditional place preference extinction and reinstatement

Bahi, Amine ; Kusnecov, Alexander ; Dreyer, Jean-Luc

In: Neuropsychopharmacology, 2008, vol. 33, p. 2726–2734

Extracellular serine proteases of the plasminogen activator family (tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA) may modulate synaptic adhesion and associate with learning behavior. Psychostimulants strongly induce their expression in the mesolimbic dopaminergic pathway, but cocaine preferentially induces uPA, whereas morphine and amphetamine...

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

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

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...