In serial electron micrographs we observed that dendrites of goldfish cone horizontal cells are either central or lateral in ribbon synaptic triads, depending on cone and horizontal cell type. The chromatic properties of cone horizontal cell responses may be explained if the cone horizontal cells act as interneurons, receiving from cones through their central processes but acting on cones through their lateral processes.

Animals↗

PubMed1975

Visual membranes: specificity of fatty acid precursors for the electrical response to illumination.

Rat electroretinograms were measured as a function of dietary supplements of purified ethyl esters of linolenic acid, linoleic acid, and oleic acid. Polyunsaturated fatty acids derived from precursors of linolenic and linoleic acids appear to be important functional components of photoreceptor cell membranes, although in equal dietary concentrations, linolenic acid precursors affect electroretinogram amplitudes to a greater extent than linoleic acid precursors. The electrical response of photoreceptor cell membranes appears to be a function of the position of the double bonds as well as a function of the total number of double bonds in fatty acid supplements.

Animals↗

PubMed1975

Determination of bacterial cell concentrations by electrical measurements.

An instrument was developed to measure the concentration of bacterial suspensions by their electrical characteristics. It employed a square-wave signal generator, a tetra-polar electrode probe, and a voltage detector in the form of an oscilloscope. When electrical measurements were made on washed bacteria obtained from cultures or urine specimens, there was a direct relationship between the concentration of the cells and the electrical characteristics of the system as reflected by voltage changes. As little as 10(3) organisms per ml could be detected. The resolution between readings taken on samples containing 10(3) to 10(9) cells per ml was found to be a function of the input frequency. The maximal resolution between concentration readings was obtained at a input frequency of 10 Hz. Thus, with relatively simple instrumentation, bacterial concentrations could be determined within a few minutes. This technique, therefore, eliminates the more lengthy laboratory procedures as plate counts or the accumulation of measurable metabolic changes (such as the utilization of radioactive or other substrates). This method can efficiently monitor clinical urine specimens when a bacteriuria is suspected.

Bacillus cereus↗