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T R Colburn

Publications and source records attributed to T R Colburn.

13 recordsLinked to original sources
PubMed1978

A novel rapid scanning microspectrophotometer and its use in measuring rhodopsin photoproduct pathways and kinetics in frog retinas.

A novel rapid scanning microspectrophotometer is described which utilizes a cathode ray tube as a measuring light source. Spectral scanning is accomplished electronically with a sampling time of 600 mus for each waveband. The cathode ray tube emission is chopped electronically into two separate beams, 180 degrees out of phase, resulting in a dual-beam configuration. A lock-in amplifier functions as a coherent detector to recover separately the signals from the two beams. The instrument generates separate voltage outputs, one proportional to the transmittance of a single sample and the other to the difference between two samples. A computer calculates both absorption and difference spectra directly from voltage measurements. A demonstration of the instrument's use to study kinetics of visual pigment photoproducts is presented. Two models of photoproduct sequence and kinetics were examined to determine which better represents the experimental data. The experiments show that environmental factors, such as pH, metabolic and respiratory state, interact in complex ways to determine the pathways and kinetics of photoproducts of rhodopsin in intact vertebrate eyes.

Animals↗
PubMedDate not supplied

Behavioral motor evaluation for neurotoxicity screening.

Behavioral motor testing is an important aspect of neurotoxicity screening. Previous test batteries have focused on simple measures of motor performance such as tapping rate, movement times and reaction times. These measures, although valuable in certain instances, do not provide a comprehensive description of motor disorders. An alternate approach to evaluate behavioral motor deficits is to use simple behaviors as an initial guide for the study of coordinated movements in more natural and thus more complex situations. The advantages of such an approach may be insights into the central neural correlates of motor disorders caused by toxic agents.

Cerebellar Diseases↗