Mrinalini Hoon

Synapse assembly and maintenance in the mammalian retina

Our lab combines high resolution imaging approaches with multi-transgenic tools, gene expression studies and electrophysiology to study retinal synaptic assembly and maintenance. We are particularly interested to uncover the factors regulating synapse dynamics during periods of retinal plasticity such as during early development and during circuit degeneration. We are interested to determine the synaptic “building blocks” of the mammalian retina and the factors that maintain retinal synaptic homeostasis. Our research employs state-of-the-art imaging and functional techniques with gene expression approaches to resolve retinal plasticity at the single synaptic protein level. Using these approaches the goal of our research is to uncover the role of molecular, cellular, vascular and activity-dependent cues that regulate retinal synapse assembly and maintenance.

Morphology of retinal output ganglion cells at the light microscopic level and an electron microsopic image of a segment of this ganglion cell receiving synaptic input. Functional light evoked spiking responses from this ganglion cell type.

Lab website

Representative publications:

Sinha R, Siddiqui TJ, Padmanabhan N, Wallin J, Zhang C, Karimi B, Rieke F, Craig AM, Wong RO, Hoon M. Neuron. 2020 Mar 18;105(6):1007-1017.e5. LRRTM4: A novel regulator of presynaptic inhibition and ribbon synapse arrangements of retinal bipolar cells.

Hoon M*, Sinha R, Okawa H, Suzuki SC, Hirano AA, Brecha N, Rieke F, Wong RO*. Proc Natl Acad Sci U S A 2015 Oct 13; 112(41): 12840-5. Epub 2015 Sep 29. Neurotransmission plays contrasting roles in the maturation of inhibitory synapses on axons and dendrites of retinal bipolar cells.* Co-corresponding authors.

Schubert T *, Hoon M *, Euler T, Lukasiewicz P, Wong RO. Neuron 2013 Apr 10;78(1):124-37. Developmental regulation and activity-dependent maintenance of GABAergic presynaptic inhibition onto rod bipolar cell axonal terminals. * These authors contributed equally to this work.

Hoon M, Soykan T, Falkenburger B, Hammer M, Patrizi A, Schmidt K.F, Sassoe-Pognetto M, Loewel S, Moser T, Taschenberger H, Brose N, Varoqueaux F. Proc Natl Acad Sci U S A 2011 Feb 15; 108(7): 3053-8. Epub 2011 Jan 31. Neuroligin-4 is localized to glycinergic postsynapses and regulates inhibition in the retina.