Lena van Giesen

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Verified

Lena verified their affiliation via an institutional email.

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• PhD
• Associate Professor at Norwegian University of Science and Technology

All nervous systems function via electrical excitability mediated by ion channels. However, channels and excitability are both ancient, preneuronal features that many cells use to rapidly adjust behavior. We systematically studied the evolutionary paths to neuronal excitability by characterizing the voltage-gated ion channel complements (VGL-chanom...

The evolution of new traits enables expansion into new ecological and behavioural niches. Nonetheless, demonstrated connections between divergence in protein structure, function and lineage-specific behaviours remain rare. Here we show that both octopus and squid use cephalopod-specific chemotactile receptors (CRs) to sense their respective marine...

Animals display wide-ranging evolutionary adaptations based on their ecological niche. Octopuses explore the seafloor with their flexible arms using a specialized “taste by touch” system to locally sense and respond to prey-derived chemicals and movement. How the peripherally distributed octopus nervous system mediates relatively autonomous arm beh...

All animals detect and integrate diverse environmental signals to mediate behavior. Cnidarians, including jellyfish and sea anemones, both detect and capture prey using stinging cells called nematocytes which fire a venom-covered barb via an unknown triggering mechanism. Here, we show that nematocytes from Nematostella vectensis use a specialized v...

All animals detect and integrate diverse environmental signals to mediate behavior. Cnidarians, including jellyfish and sea anemones, both detect and capture prey using stinging cells called nematocytes which fire a venom-covered barb via an unknown triggering mechanism. Here, we show that nematocytes from Nematostella vectensis use a specialized v...

All animals detect and integrate diverse environmental signals to mediate behavior. Cnidarians, including jellyfish and sea anemones, both detect and capture prey using stinging cells called nematocytes which fire a venom-covered barb via an unknown triggering mechanism. Here, we show that nematocytes from Nematostella vectensis use a specialized v...

All animals detect and integrate diverse environmental signals to mediate behavior. Cnidarians, including jellyfish and sea anemones, both detect and capture prey using stinging cells called nematocytes which fire a venom-covered barb via an unknown triggering mechanism. Here, we show that nematocytes from Nematostella vectensis use a specialized v...

In cells, organs and whole organisms, nutrient sensing is key to maintaining homeostasis and adapting to a fluctuating environment¹. In many animals, nutrient sensors are found within the enteroendocrine cells of the digestive system; however, less is known about nutrient sensing in their cellular siblings, the absorptive enterocytes¹. Here we use...

Heat seeking is cool Mosquitoes seek hosts using several cues, one of which is body heat. Greppi et al. hypothesized that cooling-activated receptors could be used for locating mammalian hosts if they were rewired downstream for repulsion responses (see the Perspective by Lazzari). A gene family conserved in insects and known to be responsible for...

Thermosensation is critical for avoiding thermal extremes and regulating body temperature. While thermosensors activated by noxious temperatures respond to hot or cold, many innocuous thermosensors exhibit robust baseline activity and lack discrete temperature thresholds, suggesting they are not simply warm and cool detectors. Here, we investigate...

The ionotropic receptors (IRs) are a branch of the ionotropic glutamate receptor family and serve as important mediators of sensory transduction in invertebrates. Recent work shows that, though initially studied as olfactory receptors, the IRs also mediate the detection of taste, temperature, and humidity. Here, we summarize recent insights into IR...

Monitoring neuronal responses to defined sensory stimuli is a powerful and widely used approach for understanding sensory coding in the nervous system. However, providing precise, stereotypic and reproducible cues while concomitantly recording neuronal activity remains technically challenging. Here we describe the fabrication and use of a microflui...

The sense of taste is an essential chemosensory modality that enables animals to identify appropriate food sources and control feeding behavior. In particular, the recognition of bitter taste prevents animals from feeding on harmful substances. Feeding is a complex behavior comprised of multiple steps, and food quality is continuously assessed. We...

Influence of smell on ingestion behavior of Drosophila larva. Comparison of ingestion of wCS and orco1 larvae to the indicated bitter tastants at various concentrations. For each data, 6 < n < 18. *p < 0.05, **p < 0.01, Mann–Whitney U test pair-wise comparisons. The p-values of the points marked with asterisks are as follows: 10 mM LOB, p = 0.041;...

Amounts of indigo carmine are proportional to OD values. (A) OD values of indigo carmine concentrations of 0.001–10 M on a log scale. (B) For the OD value range of 0.1–0.4 [marked as a dotted box in (A)], which was the range measured in our ingestion assay, the OD value appears to be linearly proportional to the amount of indigo carmine dye.

Ingestion assay results for 22 putative bitter tastants. Actual measurements used to construct the graphs in Figure 3 and calculations of the ingestion index (I.I.) are provided. The abbreviations for each chemical are noted, and the order of the chemicals is the same as Figure 3.

Projection patterns of pharyngeal GRNs in the larval brain. (A) Projection pattern of Gr93a-GAL4, which is expressed in DP1 and DP5. The arrowheads indicate expression from the odorant receptor neurons in the dorsal organ projecting to the larval antennal lobe, and thus is likely to be ectopic expression. (B) Projection patterns of Gr-GAL4 drivers...

Double labeling of Gr33a-QF and GrX-GAL4 in the pharyngeal sense organs. (A–C) Examination of whether Gr-GAL4 drivers that express in the DPS (A), VPS (B), and PPS (C) co-express with Gr33a-QF. Red is expression from Gr33a-QF> QUAS-mtdTomato, and green is expression from GrX-GAL4 > UAS-mcd8-GFP. The photos are taken at the positions shown as boxes...

Average number of Gr-GAL4-driven GFP-labeled cell pairs in the pharyngeal sense organs. Each Gr-GAL4 line was quantified for the number of neurons expressing the GFP reporter in the pharyngeal sense organs (DPS, VPS, and PPS). For the combinations of each Gr-GAL4 line and Gr2a-GAL4, the numbers of GFP-expressing neurons in the DPS were also quantif...

Nature Communications 7: Article number: 10687 (2016); Published: 11 February 2016; Updated: 14 March 2016. The affiliation details for Martino Colombo, Rémy Bruggmann and Richard Benton are incorrect in this article. The correct affiliations for these authors are listed below. Martino Colombo, RémyBruggmann Interfaculty Bioinformatics Unit and Swi...

Accurate perception of taste information is crucial for animal survival. In adult Drosophila, gustatory receptor neurons (GRNs) perceive chemical stimuli of one specific gustatory modality associated with a stereotyped behavioural response, such as aversion or attraction. We show that GRNs of Drosophila larvae employ a surprisingly different mode o...

The ability of some animals to regrow their head and brain after decapitation provides a striking example of the regenerative capacity within the animal kingdom. The acoel worm Symsagittifera roscoffensis can regrow its head, brain and sensory head organs within only a few weeks after decapitation. How rapidly and to what degree it also reacquires...

Genetic manipulations of neuronal activity are a corner stone of studies aimed to identify the functional impact of defined neurons for animal behavior. With its small nervous system, rapid life cycle and genetic amenability, the fruit fly Drosophila melanogaster provides an attractive model system to study neuronal circuit function. In the past tw...

Cell culture systems are widely used for molecular, genetic and biochemical studies. Primary cell cultures of animal tissues offer the advantage that specific cell types can be studied in vitro outside of their normal environment. We provide a detailed protocol for generating primary neural cell cultures derived from larval brains of Drosophila mel...