Fatty acids in the n - 3 series are important in neurological and visual development in infants. The objective of this study was to evaluate fatty acid composition in the milk of lactating women from an inland area of Texas where fish consumption is rare.
Because AMPA receptor-induced degeneration of cerebellar Purkinje cells and hippocampal pyramidal cells morphologically exhibits a type of delayed cell death often observed in numerous acute clinical conditions, understanding the mechanism of the toxicity is of major therapeutic importance. We utilized morphological and biochemical techniques in the cerebellar slice preparation to determine whether AMPA-induced dark cell degeneration of Purkinje cells represents an apoptotic-like toxicity. In addition to the previously described morphological features of DCD, additional evidence to support apoptotic mechanisms was obtained. These findings included DNA fragmentation detected by both in situ TUNEL labeling and gel electrophoresis, attenuation of AMPA-induced morphological damage using an endonuclease inhibitor, and an inhibitor of protein translation. The results of these experiments reveal that AMPA-receptor elicited toxicity of PCs is an active process that has many characteristics and features of classically defined apoptosis.
Previous reports from this laboratory and elsewhere have provided evidence that the locus coeruleus (LC) and dorsal raphe (DR) nuclei are topographically organized with respect to their efferent targets. Whereas most of these previous studies have focused on relationships between these monoamine-containing brainstem nuclei and cerebral cortex, basal ganglia, and limbic structures, they have not systematically examined the distribution of LC and DR cells that project to multiple structures with common sensory or motor functions. The goal of the present study was to characterize and compare the distributions of LC and DR cells which project to different visual areas of the rat central nervous system. Long-Evans hooded rats received unilateral pressure injections of the retrograde tracer wheat germ agglutinin-horseradish peroxidase in either the dorsal lateral geniculate, ventral lateral geniculate, or lateral posterior nucleus of thalamus; superior colliculus, cortical area 17, cortical area 18a/b; cerebellar vermis (lobules VI and VII); or paraflocculus. Transverse sections through the midbrain and pons were examined by light microscopy after performing routine tetramethyl benzidine histochemical procedures. For all cases studied, retrogradely labeled cells were observed throughout the rostrocaudal extent of the LC and DR; however, labeling patterns which were distinctive for different injection sites were noted in each of these brainstem nuclei. The major conclusion drawn from this work is that subsets of LC and DR cells which project to different target structures within the rat visual system are found in overlapping but not necessarily coextensive zones within these nuclei. These studies provide further evidence of a rough topographic ordering within both the LC and DR nuclei, as well as support a new hypothesis that the outputs from each of these nuclei are organized with respect to the sensory related functions of their efferent targets.
Putative GABAergic elements in the pontine nuclei have been studied in the rat, cat and two old world monkeys (Macaca mulatto and Papio papio) using an antiserum against GABA glutaraldehyde protein conjugates and the peroxidase antiperoxidase method. In addition, an antiserum against glutamate decar☐ylase has been used in the cat. For comparison. Golgi impregnated material from cat and macaque has been studied. In all species there is a moderatcly dense plexus of fibres with GABA-like immunoreactivity with only minor regional differences between different parts of the pontine nuclei. The number of cell bodies showing GABA-like immunoreactivity is, however, strikingly different. Thus. in the rat there are very few such neurons. In the cat, they make up about 1% of the total cell population, while the corresponding number in the two primate species is about 5%. The number is consistently somewhat higher in rostral than in caudal parts of the pontine nuclei. Numbers in the cat are essentially the same with the glutamate decar☐ylase antiserum as with the GABA antiserum.
During the mating reaction (fertilization) in the biflagellated alga, Chlamydomonas reinhardtii, mt+ and mt- gametes adhere to each other via their flagella and subsequently fuse to form quadriflagellated zygotes. In the studies reported here, we describe a monoclonal antibody directed against an mt+ flagellar surface molecule. The antibody blocks the adhesiveness of mt+ gametes, isolated mt+ flagella, and detergent extracts thereof. It has no effect on mt- gametes. Cyanogen bromide-activated Sepharose beads derivatized with the antibody bind only mt+ gametes; mt- gametes and mt+ and mt- vegetative cells are unreactive with the derivatized beads. The interaction of mt+ gametes with the beads is dynamic and cells continuously bind, detach, and rebind to the beads. Surprisingly, antibody-derivatized beads that have been incubated with mt+ gametes acquire the ability to bind mt- gametes. Moreover, extraction of the preincubated beads with detergents releases active mt+ adhesion molecules. The evidence suggests that binding of the antibody to the flagellar surface adhesion molecules causes their release from the flagellar surface, possibly mimicking the normal mechanism of flagellar de-adhesion.
Baby hamster kidney cells were mutagenized with N-methyl-N'-nitro-N-nitrosoguanidine and selected to obtain a population of non-attaching cells. The cell variant FN-1 was cloned from the non-attaching cell population, recloned, and tested for cell adhesive interactions using four different assays of fibronectin (pFN) receptor function: cell attachment and spreading on culture dishes and cell binding and phagocytosis of latex beads. On pFN-coated culture dishes, FN-1 cells had decreased attachment compared to parental cells and were unable to spread. With pFN-coated beads, only one third as many pFN-bead binding sites could be detected on FN-1 cells as on the parental cells, and the FN-1 cells were unable to phagocytose the pFN-coated beads. In other studies, the variant cells were able to attach normally and spread partially on substrata coated with polycationic ferritin, concanavalin A, or anti-BHK cell surface antibody. The results suggest that the pFN-receptor function of FN-1 cells is defective.