OHSU

Puthussery Lab

Lab Members

Structure and Function of Retinal Circuits

At the first retinal synapse, cone signals are segregated into parallel processing streams by different types of bipolar cells, the second-order neurons of the retina. There are at least 10 types of bipolar cell in the human retina, yet relatively little is known about their functional properties and how they modify cone signals to generate the distinct functional properties of ganglion cells. We are currently investigating how differences in glutamate receptors and voltage-gated ion channels influence the functional properties of bipolar cells that drive the magnocellular and parvocellular visual pathways of the primate retina. To approach these questions, we make single-cell recordings from bipolar cells and ganglion cells in whole-mounts. To complement these physiological investigations, we combine immunohistochemistry with super-resolution and confocal microscopy to study the localization of voltage-gated channels and neurotransmitter receptors in retinal neurons. Recently we have found that voltage-gated sodium channels are expressed in bipolar cells that drive the parasol ganglion cells of the magnocellular pathway, a mechanism that is likely to enhance motion detection (See our recent publication from this project: Puthussery et al., 2013, J Neurosci). 

retinal-circuits1Retinal circuits 2

Neural Signaling in the Degenerating Retina

We are also interested in how neural signaling is altered by photoreceptor degenerations such as Retinitis Pigmentosa and Age-Related Macular Degeneration. We are currently investigating changes in ion channel function in degenerating photoreceptors and examining the effect of photoreceptor degeneration on function of downstream bipolar cells.

Employment Opportunities

A postdoctoral position is currently available in the Puthussery lab for a qualified Ph.D. A background in cell biology, neuroscience or physiology is ideal. If interested, please send your curriculum vitae and the names of three references to puthusse@ohsu.edu.