Search results for "APT"

Distribution and Function of Gap Junction Coupling in Cortical GABAergic Neurons.

2013

Although gap junctions have been observed in GABAergic interneurons of several brain regions, this chapter focuses on the distribution and functions of gap junctions and connexins in inhibitory interneurons of the cerebral cortex and hippocampus. Evidence for interconnections mediated by electrical synapses is reported for at least eight cerebral cortex interneuron types, classified on the basis of morphology, electrophysiology and molecular markers. The main differences in the organization of these interneuronal networks are summarized in terms of homologous and heterologous electrical coupling and mutual chemical inhibition. The role of connexin36 (Cx36) in forming neuronal electrical syn…

Light-dependent CK2-mediated phosphorylation of centrins regulates complex formation with visual G-protein.

2008

AbstractCentrins are Ca2+-binding EF-hand proteins. All four known centrin isoforms are expressed in the ciliary apparatus of photoreceptor cells. Cen1p and Cen2p bind to the visual G-protein transducin in a strictly Ca2+-dependent way, which is thought to regulate light driven movements of transducin between photoreceptor cell compartments. These relatively slow motile processes represent a novel paradigm in light adaptation of photoreceptor cells.Here we validated specific phosphorylation as a novel regulator of centrins in photoreceptors. Centrins were differentially phosphorylated during photoreceptor dark adaptation. Inhibitor treatments revealed protein kinase CK2 as the major protein…

Temporal resolution and temporal transfer properties: gabaergic and cholinergic mechanisms.

2007

Temporal resolution is a basic property of the visual system and critically depends upon retinal temporal coding properties which are also of importance for directional coding. Whether the temporal coding properties for directional coding derive form inherent properties or critically depend upon the temporal coding mechanisms is unclear. Here, the influence of acetylcholine and GABA upon photopic temporal coding was investigated in goldfish, using flicker stimuli, in a behavioral and an electrophysiological (ERG) approach. The goldfish temporal resolution ability decreased from more than 90% correct choices at 20 Hz flicker frequency to about 65% at 45 Hz flicker frequency with a flicker fu…

Ageing via sexual perception is a by-product of male adaptive plasticity inDrosophila melanogaster

2021

ABSTRACTSensory perception of environmental cues can dramatically modulate ageing across distant taxa. For example, maleDrosophila melanogasterage faster if they perceive female cues but fail to mate (ageing via sexual perception). This finding has been a breakthrough for our understanding of the mechanisms of ageing, yet we ignore how and why such responses have evolved. Here, we usedD. melanogasterto ask whether ageing via sexual perception may be a by-product of plastic adaptive responses to female cues, and found that while long-term sexual perception leads to reproductive costs, short-term perception increases male lifetime reproductive success in a competitive environment. Simulations…

Multisensory perception of dietary faty-acids in Drosophila.

2012

International audience; Fatty-acids (FAs) are crucial for animal survival and reproduction. However, our knowledge of the mechanisms underlying the perception and preference of dietary FA is limited, particularly in invertebrates. We obtained behavioral data with wild-type Drosophila melanogaster larvae and adults showing a clear preference to some of the FAs tested (C14:0, C16:0, C18:0, C18:1, C18:2, C18:3). These data, based on tests involving both individuals and groups, showed that larvae prefer desaturated FAs whereas adults prefer saturated FAs. Moreover, we found that larval and adult responses relied on olfaction and taste modalities, and maybe also on mechanoperception [1]. We will…

2017

Prismatic adaption (PA) has been proposed as a tool to induce neural plasticity and is used to help neglect rehabilitation. It leads to a recalibration of visuomotor coordination during pointing as well as to aftereffects on a number of sensorimotor and attention tasks, but whether these effects originate at a motor or attentional level remains a matter of debate. Our aim was to further characterize PA aftereffects by using an approach that allows distinguishing between effects on attentional and motor processes. We recorded EEG in healthy human participants (9 females and 7 males) while performing a new double step, anticipatory attention/motor preparation paradigm before and after adaptat…

Adaptation to a seasonally varying environment: a strong latitudinal cline in reproductive diapause combined with high gene flow in Drosophila montan…

2011

Adaptation to seasonal changes in the northern hemisphere includes an ability to predict the forthcoming cold season from gradual changes in environmental cues early enough to prepare for the harsh winter conditions. The magnitude and speed of changes in these cues vary between the latitudes, which induces strong selection pressures for local adaptation. We studied adaptation to seasonal changes in Drosophila montana, a northern maltfly, by defining the photoperiodic conditions leading to adult reproductive diapause along a latitudinal cline in Finland and by measuring genetic differentiation and the amount of gene flow between the sampling sites with microsatellites. Our data revealed a cl…

In vitro evolution of an atrazine-degrading population under cyanuric acid selection pressure: Evidence for the selective loss of a 47kb region on th…

2011

International audience; The adaptation of microorganisms to pesticide biodegradation relies on the recruitment of catabolic genes by horizontal gene transfer and homologous recombination mediated by insertion sequences (IS). This environment-friendly function is maintained in the degrading population but it has a cost which could diminish its fitness. The loss of genes in the course of evolution being a major mechanism of ecological specialization, we mimicked evolution in vitro by sub-culturing the atrazine-degrading Pseudomonas sp. ADP in a liquid medium containing cyanuric acid as the sole source of nitrogen. After 120 generations, a new population evolved, which replaced the original on…

Comparative genomics to unravel adaptive mechanisms in Saccharomyces

2021

Saccharomyces genus is a fascinating model for evolutionary biology due to its high genetic and phenotypic diversity. The improvement in the sampling efforts during the last decade has resulted in the isolation of Saccharomyces species from a wide range of sources worldwide. S. cerevisiae is probably the most well known eukaryotic system and the dominant organism in most industrial fermentations. Due to the new challenges of the winemaking industry (e.g., global warming and changing customer demands), alternative Saccharomyces species have attracted researchers’ attention during the last decade as a poorly exploited resource of biodiversity. S. kudriavzevii and S. uvarum are two promising c…

Palaeomagnetism of the central Cuban Cretaceous Arc sequences and geodynamic implications

2009

Abstract A detailed palaeomagnetic study of Cretaceous age volcanic and sedimentary arc rocks from central Cuba has been carried out. Samples from 32 sites (12 localities) were subjected to detailed demagnetisation experiments. Nineteen sites from the Los Paso, Matagua, Provincial and Cabaiguan Formations yielded high unblocking temperature, dual polarity directions of magnetisation which pass the fold tests with confidence levels of 95% or more and are considered to be primary in origin. The palaeomagnetic inclinations are equivalent to palaeolatitudes of 9°N for the Aptian, 18°N for the Albian. A synfolding remanence identified in 5 sites from the younger Hilario Formation indicates a lat…