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VERSION:2.0
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CALSCALE:GREGORIAN
METHOD:PUBLISH
BEGIN:VEVENT
DTSTAMP:20260816T162237Z
LAST-MODIFIED:20121116T203436Z
DTSTART:20080404T173000Z
DTEND:20080404T183000Z
UID:event257@bu.edu
URL:http://physics.bu.edu/internal/events/show/257
SUMMARY:Early Steps of the Visual Cycle: Production and Clearance of Retino
	l in Vertebrate Rod and Cone Photorecetors
DESCRIPTION:Featuring M. Carter Cornwall\, Boston University School of Medi
	cine\nHosted by: Kenneth Rothschild\n\nPart of the Biophysics/Condensed Mat
	ter Seminar Series.\n\nAbstract:\nLight absorption by visual pigments in ve
	rtebrate rod and cone photoreceptors leads to the activation of the visual 
	transduction cascade.  At the same time it results in the photochemical des
	truction (bleaching) of the visual pigment leading to the formation of free
	 all-trans retinal and opsin.  The very large differential in the rates of 
	recovery of sensitivity of rods and cones following their exposure to brigh
	t light results\, at least partially\, from their widely different rates of
	 photopigment regeneration.  The series of reactions responsible for photop
	igment regeneration is collectively termed the visual cycle.  This talk wil
	l focus on a comparative examination of initial steps in the visual cycle i
	n rods and cones. Measurements of two types will be discussed.  First\, mic
	rospectrophotometry of isolated photoreceptors will be described by which d
	eterminations of visual pigment content in rods and cones are made under da
	rk-adapted and bleach-adapted conditions.  This technique allows measuremen
	t of the rate of decay of activated forms in isolated cells following light
	 exposure.  Second\, microfluorometric measurements of differential rates o
	f reduction of all-trans retinal to all-trans retinol will be described in 
	these same cell types.  Results will be considered in relation to the norma
	l maintenance of visual sensitivity under the widely varying conditions of 
	ambient light that exist in the normal environment.
LOCATION:SCI 352\, 590 Commonwealth Avenue\, 02215
STATUS:CONFIRMED
CLASS:PUBLIC
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