Abstract

Both vertebrate (Bufo Marinus and Xenopus) and invertebrate (Limulus) photoreceptors will be studied to elucidate the mechanisms of visual transduction. There are four main goals: 1. We have developed a dialysis method for controlling the cytoplasm of Limulus photoreceptors and now will apply this method to vertebrate rods. If this proves possible, the quantitative dependence of the light-activated conductance on cai2+ and the interrelationship of Cai2+ and cyclic nucleotides will be studied. Another approach will be to study the changes in transduction that occur when antibodies to specific photoreceptor proteins are introduced into the cytoplasm of rods. 2. We propose to measure single-channel current in Limulus photoreceptors after removal of the surrounding glial cells. 3. To begin the objective identification of the internal transmitter for excitation in Limulus we will attempt to show that extracts of illuminated photoreceptors contain a factor that produces a receptor potential when introduced into dark adapted photoreceptors. 4. We will study the kinetics of the receptor potential in Limulus and search for a model that accounts for the kinetics.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY001496-13
Application #
3255990
Study Section
(VID)
Project Start
1977-06-01
Project End
1987-05-31
Budget Start
1986-06-01
Budget End
1987-05-31
Support Year
13
Fiscal Year
1986
Total Cost
Indirect Cost

  Institution

Name
Brandeis University
Department
Type
Schools of Arts and Sciences
DUNS #
616845814
City
Waltham
State
MA
Country
United States
Zip Code
02454

  Publications

Segev, Ronen; Schneidman, Elad; Goodhouse, Joe et al. (2007) Role of eye movements in the retinal code for a size discrimination task. J Neurophysiol 98:1380-91
Garger, Alexander V; Richard, Edwin A; Lisman, John E (2004) The excitation cascade of Limulus ventral photoreceptors: guanylate cyclase as the link between InsP3-mediated Ca2+ release and the opening of cGMP-gated channels. BMC Neurosci 5:7
Chen, F H; Baumann, A; Payne, R et al. (2001) A cGMP-gated channel subunit in Limulus photoreceptors. Vis Neurosci 18:517-26
Garger, A; Richard, E A; Lisman, J E (2001) Inhibitors of guanylate cyclase inhibit phototransduction in limulus ventral photoreceptors. Vis Neurosci 18:625-32
Fain, G L; Lisman, J E (1999) Light, Ca2+, and photoreceptor death: new evidence for the equivalent-light hypothesis from arrestin knockout mice. Invest Ophthalmol Vis Sci 40:2770-2
Richard, E A; Ghosh, S; Lowenstein, J M et al. (1997) Ca2+/calmodulin-binding peptides block phototransduction in Limulus ventral photoreceptors: evidence for direct inhibition of phospholipase C. Proc Natl Acad Sci U S A 94:14095-9
Goldring, M A; Lisman, J E (1994) Multi-step rhodopsin inactivation schemes can account for the size variability of single photon responses in Limulus ventral photoreceptors. J Gen Physiol 103:691-726
Shin, J; Richard, E A; Lisman, J E (1993) Ca2+ is an obligatory intermediate in the excitation cascade of limulus photoreceptors. Neuron 11:845-55
Kahana, A; Robinson, P R; Lewis, L J et al. (1992) ATP-independent deactivation of squid rhodopsin. Vis Neurosci 9:595-602
Erickson, M A; Robinson, P; Lisman, J (1992) Deactivation of visual transduction without guanosine triphosphate hydrolysis by G protein. Science 257:1255-8

Showing the most recent 10 out of 19 publications