Génétique comportementale | EPFL Graph Search

La génétique comportementale est la branche de la génétique portant sur l'étude des interactions entre phénotypes comportementaux et génotype. Science récente et en plein essor, elle vise à étudier les relations entre la génétique et les caractéristiques mentales d'un individu. La génétique comportementale est fortement interdisciplinaire et fait notamment appel à la neuroscience, la génétique, l'épigénétique, l'éthologie, la psychologie, la psychiatrie et les statistiques. Certaines études montrent également la part innée de l'intelligence ou de certains traits du caractère humain, ce qui pose de nombreux problèmes éthiques (égalité des chances, manipulation génétique, eugénisme) tout en ouvrant la voie à de nouveaux traitements médicaux et une meilleure compréhension du vivant. Un exemple de méthode de détermination de caractères génétiques du comportement est l'Étude d'association pangénomique. Il s'agit, dans le cas de la génétique comportementale, de comparer le génome d'un

Orchestration of oscillatory activity to improve visual motion discrimination

Roberto Felipe Salamanca Giron

This thesis describes advances in the use of novel configurations of non-invasive brain stimulation over the visual system allowing to modulate of modifying electro-physiological activity, interregional interactions and by it, visual behavior such as motion discrimination capacity in healthy subjects. We have implemented three experimental protocols that include the application of a motion discrimination and integration task in combination with bifocal transcranial Alternating Current Stimulation (i.e. tACS) over the primary visual cortex (i.e. V1) and medio-temporal areas (i.e. V5), while varying some of the âorchestraâ parameters in each study. The common objective pursued in the three studies presented in the upcoming chapters was to evaluate physiological changes induced by tACS combined with the visual task, leading to enhanced visual performance expressed by the accurate distinction of the generalized movement orientation of a kinetogram. After introducing the scientific rationale of this thesis in Chapter 1, Chapter 2 describes whether applying two phase-shifted (Alpha) É-tACS conditions (Anti-Phase and In-Phase tACS) within the V1-V5 network were able to positively modulate behavior compared to Sham tACS. Our results suggest that the active Anti-Phase condition significantly increased visual motion discrimination compared to In-phase tACS which rather tended to decrease performances. These two case scenarios were associated with opposite changes in Alpha-Gamma oscillatory modulation (i.e. V1 phase â V5 amplitude coupling) determined by multichannel EEG. Based on these findings, in Chapter 3, we describe testing the effects of modulating Alpha-Gamma interregional interaction. Hence, two conditions V1ÉV5Æ tACS and vice versa, V1ÆV5É tACS, were behaviorally and electrophysiologically evaluated. The results suggested that there was a common electrophysiological feature between the two Verum tACS, which contrasted with Sham tACS, expressed through WPLIÆ (i.e. Weighted Phase Locking Value) connectivity. Furthermore, WPLIÉ and ZPAC V1amplitude â V5phase (i.e. Z-scored Phase Amplitude Coupling) were the inter-areal mechanisms in which both Verum conditions differed to explain the variance of their corresponding group behavior. However, the electrophysiological changes did not lead to significant difference in behavioral measures.In Chapter 4, we combined the knowledge gained in the first two studies and thus, we time-locked, short bursts of phase-shifted É-tACS to the visual stimulus onset. This permitted to find out that, despite the phase difference between the tACS conditions (i.e. In-Phase vs. Anti-Phase), there was a generalized augmentation of the performance after verum stimulation compared to the results with Sham. This amelioration was generally associated with changes in causal PSI (i.e. Phase Slope Index) flows in Æ, whereas specifically the Î-Æ modulation permitted to explain the differences in behavior between Verum and Sham. Moreover, dynamic PSI-causal Î² bottom-up and top-down flows revealed the mechanisms behind each type of Verum stimulation. These studies provided first interesting evidence that physiology-inspired bifocal tACS applied to the visual network might be used to modulate visual behavior and respective underlying mechanisms. The induced electrophysiological and behavioural effects achieved are complex and need to be studied in more details in upcoming studies.

EPFL2021

Rat model: neural substrates of the battered woman syndrome

Xavier Fontana

This study is part of a long term study on a male rat model of peripubertal stress in the Laboratory of Behavioural Genetics that shows increase aggressive behaviours against their partners. We are using here these rats in order to create a female rat model victim of Intimate Partner Violence during pregnancy and to study the generalisation of fear to all male, that is a symptom of this type of aggression, through behavioural analysis, serotonergic cell activation of the Dorsal Raphe Nucleus (DRN) and activation of other regions known to interact with the DRN such as Periaqueductal Gray (PAG) and Amygdala. This study also reveal an in-utero transmission of aggressive behaviours to the offspring of peripubertally stressed male. Our findings suggest that our model show a generalisation of fear that depends on the type of aggression experienced. This generalisation is mediated by an increase of activation of serotonergic cells of the DRN as well as a general disruption of pattern of activation at the basal level. Interestingly, our results do not show a clear direct link between activation of DRN, PAG and Amygdala during generalisation of fear

2010

The effect of frontoparietal paired associative stimulation on decision-making and working memory

Traian Popa

Previous single-site neurostimulation experiments have unsuccessfully attempted to shift decision-making away from habitual control, a fast, inflexible cognitive strategy, towards goal-directed control, a flexible, though computationally expensive strategy. We employed a dual-target neurostimulation approach in 30 healthy participants, using cortico-cortical paired associative stimulation (ccPAS) to target two key nodes: lateral prefrontal cortex (LPFC) and intraparietal sulcus (IPS), to test whether decision-making can be artificially shifted from habitual toward goal-directed control. Participants received three active stimulations, delivered at least six days apart (each involving 100 paired pulses over the IPS and LPFC, varying the interstimulus interval): two interventional, time-relevant ccPAS (10 msec interval) and one control, non-time-relevant ccPAS (100 msec interval). Following stimulation, participants completed a sequential learning task, measuring goal-directed/habitual control, and a working memory task. IPS -> LPFC ccPAS (stimulating IPS, then LPFC with a 10 msec interval) shifted decision-making from habitual toward goal-directed control, compared to control ccPAS. There was no effect of LPFC -> IPS ccPAS, nor an effect of any PAS condition on working memory. Previous studies have shown ccPAS effects outside the motor domain targeting prefrontal regions on response inhibition, attentional bias, and alpha asymmetry. The present study measures the behavioural effects of parietal-prefrontal PAS, focusing on a highly complex decision-making task and working memory. If confirmed in larger studies, this would be the first instance of neurostimulation successfully shifting decision-making from habitual to goal-directed control, putatively via inducing long-term potentiation between the IPS and LPFC. However, we found no effect in the other direction (LPFC -> ccPAS), and no effect on working memory overall. PAS is a relatively new neuromodulatory technique in the cognitive arsenal, and this study could help guide future approaches in healthy and disordered decision-making. (C) 2019 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

ELSEVIER MASSON, CORPORATION OFFICE2019