Maël Duménieu's research while affiliated with Aix-Marseille Université and other places

... However, contrary to common belief that practice learning is stronger than exposure learning, we found that repetitive exposure to orthogonal orientations led to superior learning ( Figure 6B, right). That is, despite the fact that subjects did not perform any visual task at the exposed location for 28 sessions, they were nonetheless able to discriminate finer orientation differences at the exposed location compared to the practice location (Sessions [29][30][31][32][33][34][35][36][37][38]. This demonstrates that passive exposure to orthogonal orientations induces stronger learning than task repetition (p < 0.008, Student's t-test), and that exposure learning develops at a faster time course than practice learning. ...

... As in other biological membranes, the major classes of lipids found at synaptic plasma membranes are cholesterol, sphingolipids and glycerol backbone-based phospholipids [136]. Of these, cholesterol and saturated sphingolipids and phospholipids are particularly enriched in membrane domains [137], and the cholesterol concentration in brain accounts for~25% of the human body's total content. ...

... Mature DG GCs have been shown to fire action potentials, preferentially in bursts. The GC bursting has been suggested to play an important role in proper transferring information from MF synapses to CA3 (Dumenieu et al., 2018). The low voltage-activated T-type calcium channels have been shown to mediate burst firing of mature GCs in rodents, such that mice lacking Cav3.2 T-type calcium channels showed impairment in burst firing, synaptic plasticity, and effective information transfer from mature GCs to the CA3 (Dumenieu et al., 2018), as well as impaired memory retrieval for context-cued trace fear conditioning and passive avoidance (Chen et al., 2012) accompanied by increased anxiety (Gangarossa et al., 2014). ...

... As is the case for other classes of transmembrane channels, K 1 channels generally display striking variations in their distributions and relative densities in different cellular compartments and are known to form dense clusters (307,308). In addition, there have been several reports of alterations in normal gating behavior of K 1 channels within clusters that we describe in sects. ...

... However, the results presented on backpropagation are in line with what has been observed in experimental studies, such as Golding et al. (2001), where it was observed the bAP amplitude is reduced when further away from the soma, and especially beyond 300 µm. The reason for attenuation is likely due to two factors: (1) changes in active conductance with respect to distance from the soma, where at distal dendrites there is a higher density of potassium channels and low density of calcium and sodium channels (Bikbaev et al., 2016); and (2) the branching of the dendritic arbors, which has also been seen to contribute to the attenuation of the bAP (Golding et al., 2001). In distal synapses, there may be other mechanisms at play that may more prominently influence signaling and plasticity to compensate for attenuated bAP, such as modulation by glial cells and neurotransmitters (acetylcholine, brain derived neurotrophic factor, dopamine noradrenaline) (Edelmann et al., 2017). ...

... The main mechanism underlying AHP is the activation of voltage-and calcium-dependent potassium currents. However, in some neuronal types, such as mitral cells (MCs), the main output neurons of the olfactory bulb, the synaptic transmission also contributes to the AHP shape (Duménieu et al., 2015). Differences in the activation-inactivation kinetics and calcium sensitivity of the different subtypes of potassium channels, underlying AHP, are responsible for a division of its course into three successive components, a fast, a medium, and a slow AHP, that differ in onset times, rise, and decay kinetics (Schwindt et al., 1988;Sah and Faber, 2002;Andrade et al., 2012). ...