Abstract. We have used cultured sympathetic neurons to identify microtubule proteins (tubulin and microtubule-associated proteins [MAPs]) and neurofilament (NF) proteins in pure preparations of axons and also to examine the distribution of these proteins between axons and cell bodies + dendrites. Pieces of sympathetic ganglia containing thousands of neurons were plated onto culture dishes and allowed to extend neurites. Dendrites remained confined to the ganglionic explant or cell body mass (CBM), while axons extended away from the CBM for several millimeters. Axons were separated from cell bodies and dendrites by dissecting the CBM away from cultures, and the resulting axonal and CBM preparations were analyzed using biochemical, immunoblotting, and immunoprecipitation methods. Cultures were used after 17 d in vitro, when 40-60% of total protein was in the axons.The 68,000-mol-wt NF subunit is present in both axons and CBM in roughly equal amounts. The 145,000-and 200,000-mol-wt NF subunits each consist of several variants which differ in phosphorylation state; poorly and nonphosphorylated species are present only in the CBM, whereas more heavily phosphorylated forms are present in axons and, to a lesser extent, the CBM. One 145,000-mol-wt NF variant was axon specific.Tubulin is roughly equally distributed between CBM and axon-like neurites of explant cultures. MAP-1 a, MAP-I b, MAP-3, and the 60,000-mol-wt MAP are also present in the CBM and axon-like neurites and show distribution patterns similar to that of tubulin. In contrast, MAP-2 was detected only in the CBM, while tau and the 210,000-mol-wt MAP were greatly enriched in axons compared to the CBM. In immunostaining analyses, MAP-2 localized to cell bodies and dendrite-like neurites, but not to axon-like neurites, whereas antibodies to tubulin and MAP-lb localized to all regions of the neurons.The regional differences in composition of the neuronal cytoskeleton presumably generate corresponding differences in its structure, which may, in turn, contribute to the morphological differences between axons and dendrites.N EURONS have very elaborate morphologies that are characterized by axonal and dendritic neurites. These highly anisotropic processes can be distinguished from each other on the basis of several morphological criteria (3, 51). For example, axons have lengths usually measured in mm to cm or more and maintain a relatively uniform diameter along their length, whereas dendrites are usually much shorter than axons, having lengths <<1 ram, and taper as they extend away from the cell body. Axons and dendrites also generate very distinctive types of branching patterns (28). The morphological differences between axons and dendrites contribute to their unique physiological properties. Many of the morphological parameters that distinguish axons from dendrites can be generated by neurons grown in tissue culture (2, 3), suggesting that these features are endogenously determined. We have been studying the cellular basis for the differences between axonal and d...

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The effects of screw speed and additives (sugar and salt) on processing and product variables of corn meal extruded with a twin-screw extruder were studied. Higher salt (O-3%) and sugar concentrations (O-4%) in the feed decreased the die pressure, % torque and specific energy. But at 6 and 8%, sugar increased the three processing parameters. Higher screw speed (250 vs 200 rpm) decreased die pressure and % torque, but increased specific energy. The addition of salt and sugar enhanced extrudate radial and axial expansions, but reduced product bulk density and breaking strength. An increase in screw speed decreased radial expansion and bulk density, but increased axial expansion and breaking strength.

Puffing of rice cakes using both long-grain and medium-grain brown rice was studied. The effects of tempering moisture, heating temperature, and heating time on various rice cake quality attributes were investigated. A greater specific cake volume was obtained at a lower tempering moisture, higher heating temperature, and longer heating time for long-grain brown rice. For medium-grain rice, a higher tempering moisture yielded a larger specific cake volume. The lightness of rice cakes correlated well with their expansion; the less expanded cake always had a lighter color. Medium-grain brown rice also produced cakes that were much more fragile than those produced from long-grain brown rice.

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