Université de Fribourg

Influence of plasticity and learning on evolution under directional selection

Paenke, Ingo ; Sendhoff, Bernhard ; Kawecki, Tadeusz J.

In: American Naturalist, 2007, vol. 170, no. 2, p. E47-E58

Phenotypic plasticity and related processes (learning, developmental noise) have been proposed to both accelerate and slow down genetically based evolutionary change. While both views have been supported by various mathematical models and simulations, no general predictions have been offered as to when these alternative outcomes should occur. Here we propose a general framework to study the...

Université de Fribourg

The effect of learning on experimental evolution of resource preference in Drosophila melanogaster

Kawecki, Tadeusz J. ; Mery, Frederic

In: Evolution, 2004, vol. 58, p. 757-767

Learning is thought to be adaptive in variable environments, whereas constant, predictable environments are supposed to favor unconditional, genetically fixed responses. A dichotomous view of behavior as either learned or innate ignores a potential evolutionary interaction between the learned and innate components of a behavioral response. We addressed this interaction in the context of...

Université de Fribourg

Differential patterns of functional and structural plasticity within and between inferior frontal gyri support training-induced improvements in inhibitory control proficiency

Chavan, Camille F. ; Mouthon, Michael ; Draganski, Bogdan ; Zwaag, Wietske van der ; Spierer, Lucas

In: Human Brain Mapping, 2015, vol. 36, no. 7, p. 2527–2543

Ample evidence indicates that inhibitory control (IC), a key executive component referring to the ability to suppress cognitive or motor processes, relies on a right-lateralized fronto-basal brain network. However, whether and how IC can be improved with training and the underlying neuroplastic mechanisms remains largely unresolved. We used functional and structural magnetic resonance imaging to...

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

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

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

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...