. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 156 S. A. ARKETT ET AL, vae were raised according to Chia and Koss (1988a). The veligers used in these experiments were from the same cohort and random samples from the cohort were checked for metamorphic competency according to Chia and Koss (1988a). Only when the cohort reached compe- tency did we attempt to record from a receptor cell. Veligers were pipetted into a Sylgard (Dow Corning)- lined recording dish containing ml of high Mg++, low Ca+" seawater mixture (12-15°C) consisting of natural seawater, isotonic (
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 156 S. A. ARKETT ET AL, vae were raised according to Chia and Koss (1988a). The veligers used in these experiments were from the same cohort and random samples from the cohort were checked for metamorphic competency according to Chia and Koss (1988a). Only when the cohort reached compe- tency did we attempt to record from a receptor cell. Veligers were pipetted into a Sylgard (Dow Corning)- lined recording dish containing ml of high Mg++, low Ca+" seawater mixture (12-15°C) consisting of natural seawater, isotonic ( Af) MgCl:, and Co++-seawater in a ratio of 2:1 (v/v/v). Co++-seawater consisted of 430 mM NaCl, 10 mM CoCl:, 10 mM KC1, 30 rruU MgCl:, 20 mAI MgSO4, 10 mA/TES pH (Arkett et 1987). We derived this bath mixture empirically and found that it abolishes most movements of the foot. Veli- gers were held in place by pinning the base of the velum with a cactus spine. A second spine was used to orient the veliger such that one side of the propodium and re- ceptor field faced upward. Conventional intracellular electrode recording tech- niques were used. Three M KC1 (20-40 MO) and Lucifer Yellow CH (Sigma, tip-filled with 5% LY and back-filled with 1 M LiCl;; 80-100 MO) electrodes were routinely used. Lucifer Yellow was iontophoresed into receptor cells by passing brief (1-3 s duration, up to 5 nA) hyper- polarizing current pulses for about 3-5 min. Veligers were either viewed live, or fixed in 4% paraformaldehyde in M sodium phosphate buffer pH for 1 h at room temperature. After washing briefly in the same buffer, ve- ligers were dehydrated in a graded series of ethanol, cleared in methyl salicylate and either viewed whole or embedded in Spurr's for sectioning. Whole mounts and 2 ^m sections were viewed with a Zeiss Photomicroscope II equipped with BP 450-490, FT 510 and BP 520-560 filters for Lucifer Yellow visualization. The stimulus used to evoke settlement b
Size: 1163px × 2150px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
