During my PhD I investigated various aspects of vertebrate photoreceptor function. In particular I characterised the functional relevance of electrical coupling between rods and cones in the mouse retina. I also examined evolutionary aspects of vision by performing some of the first recordings from the lamprey retina. We found that these primitive-looking vertebrates, whose last common ancestor with us lived in the Cambrian period, have rod-like photoreceptors capable of detecting single photons. This suggests that highly sensitive photoreceptors had already evolved from an ancestral cone in the Cambrian, conferring dim-light vision to early vertebrates.
Currently, I am interested in invertebrate phototransduction. The exceptional performance of Drosophila photoreceptors is well known: from sunrise to sunset fly photoreceptors maintain their ability to respond to changes in light despite being exposed to a huge range of ambient illuminations. At the core of this unique ability lies calcium. Calcium is involved in every step of the phototransduction cascade, but key targets are the light activated channels themselves: TRP and TRPL. How calcium regulates these channels has still to be clarified. Interest in unravelling the biochemical machinery of rhabdomeric photoreceptors goes beyond evolutionary aspects, since close relatives of these have been identified in the mammalian retina in the intrinsically photosensitive ganglion cells. My main goal is to study calcium-dependent modulation of fly photranduction using single cell recordings from dissociated ommatidia from mutant flies, as well as with genetically encoded calcium indicators.
Schön C, Asteriti S, Koch S, Sothilingam V, Garrido MG, Tanimoto N, Herms J, Seeliger MW, Cangiano L, Biel M, Michalakis S, (2016), Loss of HCN1 enhances disease progression in mouse models of CNG channel-linked retinitis pigmentosa and achromatopsia, Hum. Mol. Genet. doi: 10.1093/hmg/ddv639.
Asteriti S, Grillner S, Cangiano L, (2015), A Cambrian origin for vertebrate rods, eLife 4: e07166, 1–16
Asteriti S, Cangiano L, (2015), Slow light response kinetics in rods points towards a perturbation of the normal cellular milieu, J Physiol, 593: 2975–6
Asteriti S, Dal Cortivo G, Pontelli V, Cangiano L, Buffelli M, Dell'Orco D, (2015), Effective delivery of recombinant proteins to rod photoreceptors via lipid nanovesicles, Biochem Biophys Res Commun, 461: 665–70
Asteriti S, Gargini C, Cangiano L, (2014), Mouse rods signal through gap junctions with cones, eLife, 3: e01386, 1–21
Cangiano L, Asteriti S, Cervetto L, Gargini M, (2012), The photovoltage of rods and cones in the dark-adapted mouse retina, J Physiol, 590: 3841–55
Asteriti S, Daniele S, Porchia F, Dell’Anno MT, Fazzini A, Pugliesi I, Trincavelli M, Taliani S, Martini C, Mazzoni M, Gilchrist A, (2012), Modulation of PAR1 signaling by benzimidazole compounds, British Journal of Pharmacology, 167, 80–94