Joshua Singer headshot
Contact Info
Phone: 301.405.9784
Fax: 301.314.9489
Office Address: 3210 Biology-Psychology Bldg
Joshua Singer
Department Chair and Professor

Research Interests and Goals

Generally, I want to understand how the output of a neural circuit reflects the behaviors of the individual synapses and neurons that compose it. The mammalian retina is a model circuit well suited to the study of this issue: it is well-characterized anatomically and physiologically, but the nature of synaptic transmission between its component neurons is understood poorly.

Rod bipolar pathway of mammalian retinaSpecifically, my laboratory studies a specialized group of neurons that compose a retinal circuit called the rod bipolar cell pathway (see figure at right). This pathway functions during night vision, and signaling within it begins when rods absorb light. Rods are the receptive cells that are most sensitive to light: single photons can activate rods and cause very small electrical signals to be generated within them. Electrical signals from rods are propagated first to rod bipolar cells, then to AII amacrine cells (AIIs), and finally to ganglion cells, the neurons that project to the brain.
Signaling within the rod bipolar cell pathway is significant because the circuit is sensitive enough to encode small rod signals generated by single photons and flexible enough to encode much larger rod signals that arise from the widely variable light intensities within ever-changing natural scenes. Thus, the rod bipolar pathway exhibits both sensitivity and a wide operating, or dynamic, range. My laboratory studies two aspects of signaling in the rod bipolar pathway: synaptic transmission from rod bipolar cells to AIIs and processing of rod bipolar cell outputs by AIIs and ganglion cells. We assess synaptic transmission by recording neurons' electrical activity. Recordings are complemented by anatomical and computational analyses and ultimately used to understand features of the retina's responses to visual stimuli. 
From our studies, we hope not only to understand signaling within the rod bipolar pathway but also to generate a broader understanding of how the properties of neurons and their synapses give rise to circuit behavior. Our work is of interest to sensory neuroscientists specifically and to neuroscientists generally: the former because it relates to the coding of sensory information by ribbon synapses and retinal circuits and the latter because it provides an understanding of the basic principles of synaptic communication between neurons and neural circuit function. As well, our work may provide insights that serve as a basis for therapies for human diseases that affect the first stages of visual processing. Such diseases include retinitis pigmentosa and macular degeneration.

Awards

2011 Research to Prevent Blindness Special Scholar Award for Retinitis Pigmentosa
2007-2009 Alfred P. Sloan Foundation Research Fellowship
2002-2007 NINDS Career Development (K-22) Award


Teaching

BSCI440: Mammalian Physiology
BSCI339G: Advanced Physiology
BSCI338N: Diseases of the Nervous System
BSCI279: Readings in Physiology (Registration by permission only)


Education

Sc.B., Brown University, 1993
Ph.D., University of Washington, 1998
Postdoctoral Research, NIH, 1998-2004


All Publications 

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Latest Publications via PubMed

Ishibashi M,Keung J,Morgans CW,Aicher SA,Carroll JR,Singer JH,Jia L,Li W,Fahrenfort I,Ribelayga CP,Massey SC
Elife. 2022 Apr 26;11:. pii: e73039. doi: 10.7554/eLife.73039. Epub 2022 Apr 26
Grimes WN,Sedlacek M,Musgrove M,Nath A,Tian H,Hoon M,Rieke F,Singer JH,Diamond JS
Curr Biol. 2022 Jan 24;32(2):315-328.e4. doi: 10.1016/j.cub.2021.11.005. Epub 2021 Nov 24
Pottackal J,Singer JH,Demb JB
Front Cell Neurosci. 2021;15:660773. doi: 10.3389/fncel.2021.660773. Epub 2021 Jul 26
Liang CQ,Zhang G,Zhang L,Chen SY,Wang JN,Zhang TT,Singer JH,Ke JB
eNeuro. 2021 Jan-Feb;8(1):. pii: ENEURO.0257-20.2020. doi: 10.1523/ENEURO.0257-20.2020. Epub 2021 Jan 6
Pottackal J,Singer JH,Demb JB
Front Cell Neurosci. 2020;14:604163. doi: 10.3389/fncel.2020.604163. Epub 2020 Nov 26
Park SJ,Lieberman EE,Ke JB,Rho N,Ghorbani P,Rahmani P,Jun NY,Lee HL,Kim IJ,Briggman KL,Demb JB,Singer JH
Elife. 2020 May 15;9:. pii: e56077. doi: 10.7554/eLife.56077. Epub 2020 May 15
Shi Q,Gupta P,Boukhvalova AK,Singer JH,Butts DA
Sci Rep. 2019 Jun 18;9(1):8713. doi: 10.1038/s41598-019-45048-8. Epub 2019 Jun 18
Pangrsic T,Singer JH,Koschak A
Physiol Rev. 2018 Oct 1;98(4):2063-2096. doi: 10.1152/physrev.00030.2017. Epub
Fernandez DC,Fogerson PM,Lazzerini Ospri L,Thomsen MB,Layne RM,Severin D,Zhan J,Singer JH,Kirkwood A,Zhao H,Berson DM,Hattar S
Cell. 2018 Sep 20;175(1):71-84.e18. doi: 10.1016/j.cell.2018.08.004. Epub 2018 Aug 30
Graydon CW,Lieberman EE,Rho N,Briggman KL,Singer JH,Diamond JS
Curr Biol. 2018 Sep 10;28(17):2739-2751.e3. doi: 10.1016/j.cub.2018.06.063. Epub 2018 Aug 16
Park SJH,Pottackal J,Ke JB,Jun NY,Rahmani P,Kim IJ,Singer JH,Demb JB
J Neurosci. 2018 Apr 11;38(15):3753-3766. doi: 10.1523/JNEUROSCI.2518-17.2018. Epub 2018 Mar 23
Mortensen LS,Park SJH,Ke JB,Cooper BH,Zhang L,Imig C,Löwel S,Reim K,Brose N,Demb JB,Rhee JS,Singer JH
Cell Rep. 2016 Jun 7;15(10):2239-2250. doi: 10.1016/j.celrep.2016.05.012. Epub 2016 May 26
Demb JB,Singer JH
Neuron. 2016 Apr 20;90(2):207-9. doi: 10.1016/j.neuron.2016.04.007. Epub
Pallotto M,Watkins PV,Fubara B,Singer JH,Briggman KL
Elife. 2015 Dec 9;4:. pii: e08206. doi: 10.7554/eLife.08206. Epub 2015 Dec 9
Demb JB,Singer JH
Annu Rev Vis Sci. 2015 Nov 24;1:263-289. doi: 10.1146/annurev-vision-082114-035334. Epub