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Richard H. Masland, Ph.D.

Charles Anthony Pappas Professor of Neuroscience in the Department of Surgery

Massachusetts General Hospital
50 Blossom Street
55 Fruit St
Boston, MA 02114
Telephone: 617-726-3888
Fax: 617- 726-5336
Email: masland@helix.mgh.harvard.edu
Lab Webpage: The Masland HMMI Research Page
Additional Lab Webpage: The Masland MGH/Neurosurgery Lab Page
Predocs: 0 Postdocs: 4 Completed PhD's: 4

Richard Masland

Research in this laboratory concerns local cellular interactions within the retina. Mammalian retinas contain a surprising diversity of cell types. Amacrine cells, upon which we have especially concentrated, exist in at least 20 different morphological subclasses. By fluorescent staining many of these classes can be visualized by distinct, reproducible populations in histological material or intact retinas in vitro during electrophysiological recording.

The broad questions under investigation are: (1) why this diversity exists, i.e., what functions the many cells carry out; (2) how orderly structural relations among the cells are created and maintained. At present, we have two main lines of work. The first is a systematic, quantitative study of the mosaics and arrays of retinal neurons. The goal is to account for all of players in the retina's microcircuitry. Toward this end, we have invented a new method for revealing the shapes of dendrites, which uses a photochemical reaction initiated by irradiation of a single cell’s nucleus with a microbeam of light. The method is in effect a quantitative Golgi, in the sense that almost every cell targeted is successfully filled. We have used it to characterize the population of amacrine cells and are now extending it to other retinal neurons. Recently we have adapted molecular methods to the study of retinal cell populations, especially the directed expression of reporter molecules in specific retinal cell classes.

 

References:

  • Chiao C-C, Masland RH. Contextual tuning of direction-selective retinal ganglion cells. Nature Neurosci 2003; 6:1251-1252.
  • MacNeil MA, Heussy JK, Dacheux RF, Raviola E, Masland RH. The population of bipolar cells in the rabbit retina. J Comp Neurol 2004; 472: 73-86.
  • Koizumi A, Jakobs TC, Masland RH. Inward rectifying currents stabilize the membrane potential in dendrites of mouse amacrine cells: Patch-clamp recordings and single-cell RT-PCR. Mol Vision 2004; 10:328-340.
  • Lin B, Wang SW, Masland RH. Retinal ganglion cell type, size, and spacing can be specified independent of homotypic dendritic contacts. Neuron 2004; 43: 475-485.
  • Lin B, Masland RH. Synaptic contacts between an identified type of ON cone bipolar cell and ganglion cells in the mouse retina. Eur J Neurosci 2005; 21: 1257-1270.