. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 80 C. S. COBB AND R. WILLIAMSON microelectrode amplifier (AxoClamp 2B amplifier, Axon Instruments, Inc. USA) was used for recording resting, venerator, and receptor potentials and for injecting current pulses through the intracellular microelectrode. In some experiments, octopus photoreceptor cells were injected iontophoretically with the fluorescent napthalimide dye Lucifer yellow CH (Stewart. 1978; Sigma, UK). For this the microelectrodes were back-filled with 3% Lucifer yel- low in 1 M LiCl and had resistances of 150-200
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 80 C. S. COBB AND R. WILLIAMSON microelectrode amplifier (AxoClamp 2B amplifier, Axon Instruments, Inc. USA) was used for recording resting, venerator, and receptor potentials and for injecting current pulses through the intracellular microelectrode. In some experiments, octopus photoreceptor cells were injected iontophoretically with the fluorescent napthalimide dye Lucifer yellow CH (Stewart. 1978; Sigma, UK). For this the microelectrodes were back-filled with 3% Lucifer yel- low in 1 M LiCl and had resistances of 150-200 MO. Injections of hyperpolari/ing current ( nA at 1 Hz) re- sulted in rapid movement of Lucifer yellow into the cells, and dye filling was considered complete after 30 min. Resting potential was recorded during cell impalement and generator potentials were recorded in response to lieht flashes, before switching to current injection in these experiments. Immediately after dye injection, the prepara- tion was photographed in whole mount under an epiflu- orescent microscope, using color film (400 ASA). For normal recordings, the signal from the microelec- trodes was amplified and, together with the signal from the photocell monitor, was passed to a computer-con- trolled signal averager (CED 1401 computer interface running Sigavg software, Cambridge Electronic Design, UK). Typically, 5-10 responses were averaged to im- prove signal-to-noise ratios, and repeated light flash stim- uli were separated by at least 20 s. The octopus prepara- tions remained viable for at least 6 h. Illumination of the experimental 'darkroom' was provided by red safelight (>650nm). Illumination of ^W/cnr with this red light was found not to cause a decrement in photore- sponse. Epistellar body iniiervutio/i Innervation of the epistellar body was studied by ortho- dromic filling from the epistellar body using the lipophilic dye Di-I (Honig and Hume, 1989) in 10 animals. With the aid of a dissectin
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
