An AC constant-response method for electrophysiological measurements of spectral sensitivity functions

• Published in: Journal of neuroscience methods Vol. 68; no. 2; pp. 203 - 210
• Main Authors: de Souza, J.M., DeVoe, R.D., Schoeps, C., Ventura, D.F.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-10-1996; Elsevier Science
• Subjects: Animals; Bees; Biological and medical sciences; Color vision; Electrophysiology; Experimental automation; Fundamental and applied biological sciences. Psychology; General aspects and techniques. Study of several systematic groups. Models; Insect; Invertebrates; Miscellaneous techniques; Photoreceptor Cells - physiology; Sensitivity and Specificity; Spectral sensitivity; Techniques; Visual Cortex - physiology; Electrophysiology; Spectral sensitivity; Color vision; Insect; Experimental automation; Eye; Visual system; Arthropoda; Insecta; Photoreceptor; Measurement method; Invertebrata
• ISSN: 0165-0270; 1872-678X
• DOI: 10.1016/0165-0270(96)00076-3

A number of methods have been used in the past to measure spectral sensitivity (
S(λ)) functions of electric responses in the visual system. We present here a microcomputer-based, AC, constant-response method for automatic on-line measurement of
S(λ) in cells with or without a sustained tonic response. It is based on feedback adjustment of light intensity to obtain constant peak-to-peak amplitudes of response to a flickering stimulus as the spectrum is scanned between 300 and 700 nm in 4 nm steps. It combines the advantages of: (1) on-line presentation of
S(λ) curves; (2) constant light adaptation; (3) sampling of many points; and (4) fast data collection time. The system can be applied to sensitivity or threshold (e.g.,
S(λ), dark adaptation, receptive field) measurements of any electrically recorded visual response.