Honors & Awards
Long-Term Fellowship, Human Frontier Science Program (2019-2022)
Best Publication Award, Category Systems and Behavioural Neuroscience, Swiss Society for Neuroscience (2019)
Fellowship, Early Postdoc Mobility, Swiss National Science Foundation (SNSF) (2018-2019)
Summa Cum Laude, PhD thesis, Friedrich-Miescher-Institute for Biomedical Research (FMI) Basel (2017)
Swiss OphtAWARD, Category "Best Experimental Work", Swiss Society of Ophthalmology (2016)
PhD Fellowship, Boehringer Ingelheim Fonds (BIF) (2011-2013)
Doctor of Philosophy, Universitat Basel (2017)
Master of Science, Universitat Zurich (2009)
Bachelor of Science, Eidgenossische Technische Hochschule (ETH Zurich) (2007)
How Diverse Retinal Functions Arise from Feedback at the First Visual Synapse.
Many brain regions contain local interneurons of distinct types. How does an interneuron type contribute to the input-output transformations of a given brain region? We addressed this question in the mouse retina by chemogenetically perturbing horizontal cells, an interneuron type providing feedback at the first visual synapse, while monitoring the light-driven spiking activity in thousands of ganglion cells, the retinal output neurons. We uncovered six reversible perturbation-induced effects in the response dynamics and response range of ganglion cells. The effects were enhancing or suppressive, occurred in different response epochs, and depended on the ganglion cell type. A computational model of the retinal circuitry reproduced all perturbation-induced effects and led us to assign specific functions to horizontal cells with respect to different ganglion cell types. Our combined experimental and theoretical work reveals how a single interneuron type can differentially shape the dynamical properties of distinct output channels of a brain region.
View details for DOI 10.1016/j.neuron.2018.06.001
View details for PubMedID 29937281
Congenital Nystagmus Gene FRMD7 Is Necessary for Establishing a Neuronal Circuit Asymmetry for Direction Selectivity
2016; 89 (1): 177–93
Neuronal circuit asymmetries are important components of brain circuits, but the molecular pathways leading to their establishment remain unknown. Here we found that the mutation of FRMD7, a gene that is defective in human congenital nystagmus, leads to the selective loss of the horizontal optokinetic reflex in mice, as it does in humans. This is accompanied by the selective loss of horizontal direction selectivity in retinal ganglion cells and the transition from asymmetric to symmetric inhibitory input to horizontal direction-selective ganglion cells. In wild-type retinas, we found FRMD7 specifically expressed in starburst amacrine cells, the interneuron type that provides asymmetric inhibition to direction-selective retinal ganglion cells. This work identifies FRMD7 as a key regulator in establishing a neuronal circuit asymmetry, and it suggests the involvement of a specific inhibitory neuron type in the pathophysiology of a neurological disease.
View details for DOI 10.1016/j.neuron.2015.11.032
View details for Web of Science ID 000373564300016
View details for PubMedID 26711119
View details for PubMedCentralID PMC4712192
Causal evidence for retina-dependent and -independent visual motion computations in mouse cortex
2017; 20 (7): 960-+
How neuronal computations in the sensory periphery contribute to computations in the cortex is not well understood. We examined this question in the context of visual-motion processing in the retina and primary visual cortex (V1) of mice. We disrupted retinal direction selectivity, either exclusively along the horizontal axis using FRMD7 mutants or along all directions by ablating starburst amacrine cells, and monitored neuronal activity in layer 2/3 of V1 during stimulation with visual motion. In control mice, we found an over-representation of cortical cells preferring posterior visual motion, the dominant motion direction an animal experiences when it moves forward. In mice with disrupted retinal direction selectivity, the over-representation of posterior-motion-preferring cortical cells disappeared, and their responses at higher stimulus speeds were reduced. This work reveals the existence of two functionally distinct, sensory-periphery-dependent and -independent computations of visual motion in the cortex.
View details for DOI 10.1038/nn.4566
View details for Web of Science ID 000404115100012
View details for PubMedID 28530661
View details for PubMedCentralID PMC5490790
Rods in daylight act as relay cells for cone-driven horizontal cell mediated surround inhibition
2014; 17 (12): 1728–35
Vertebrate vision relies on two types of photoreceptors, rods and cones, which signal increments in light intensity with graded hyperpolarizations. Rods operate in the lower range of light intensities while cones operate at brighter intensities. The receptive fields of both photoreceptors exhibit antagonistic center-surround organization. Here we show that at bright light levels, mouse rods act as relay cells for cone-driven horizontal cell-mediated surround inhibition. In response to large, bright stimuli that activate their surrounds, rods depolarize. Rod depolarization increases with stimulus size, and its action spectrum matches that of cones. Rod responses at high light levels are abolished in mice with nonfunctional cones and when horizontal cells are reversibly inactivated. Rod depolarization is conveyed to the inner retina via postsynaptic circuit elements, namely the rod bipolar cells. Our results show that the retinal circuitry repurposes rods, when they are not directly sensing light, to relay cone-driven surround inhibition.
View details for DOI 10.1038/nn.3852
View details for Web of Science ID 000345484000020
View details for PubMedID 25344628