Cytoplasmic streaming in giant internodal cells of green algae is caused by ATP-dependent sliding between actin cables fixed on chloroplast rows and cytoplasmic myosin molecules attached to cytoplasmic organelles. Its velocity (>/=50 micro m s(-1)) is many times larger than the maximum velocity of actin-myosin sliding in muscle. We studied kinetic properties of actin-myosin sliding causing cyto...

The chloroplasts of internodal cells of Nitella are fixed to a stationary layer of cytoplasm whereas the nuclei and most of the cytoplasm stream along the longitudinal axis. Isolated internodal cells were maintained for several days with half the cell kept in the dark, the other half kept under continuous light. Photosynthetic activity of the cells was checked by placing the cell evenly illumin...

1. Conduction of impulses in peripheral myelinated fibers of a nerve trunk is a continuous process, since with uninjured nerve fibers: (a) within each internodal segment the conduction time increases continuously and linearly with increasing conduction distance; (b) the presence of nodes of Ranvier does not result in any detectable discontinuity in the conduction of the impulse; (c) the ascendi...

The potential distribution within the internodal axon of mammalian nerve fibers is derived by applying known node potential waveforms to the ends of an equivalent circuit model of the internode. The complete spatial/temporal profile of action potentials synthesized from the internodal profiles is used to compute the node current waveforn, and the extracellular action potential around fibers cap...

Membrane current responses to sudden potential changes were recorded in solutions of various [K](o) on 52 internodal cells of Nitella clavata. The membrane current after sudden depolarization had a component sensitive to [K](o) which increased with time from 0.3 to 2.0 s and remained steady thereafter. This late current became zero at values of E and [K](o) which suggests that the current was n...

The hydraulic resistance was measured on internodal cells of Chara corollina and Nitellopsis obtusa using the method of transcellular osmosis described by KAMIYA and TAzAwA in 1956. The transcellular hydraulic resistances of N. obtusa and C. corollina are 2.63 and 1.11 pm -I sPa, resepectively. These values correspond to osmotic permeability coefficients (P os) of 102.6 and 243.1 flm s I, respe...

We have used fluorescent dextran tracers to test the tightness of the paranodal junction of living or fixed myelinated fibers in mouse sciatic nerve. Both 3 and 70 kDa tracers are able to penetrate from the perinodal space symmetrically into the paranodes on either side of the node of Ranvier at a rate consistent with diffusion through an elongated helical pathway between the paranodal terminal...

Crataeva religiosa G. Forst. var. nurvala (Buch.-Ham.) Hook. F. & Thomson (syn. Crataeva nurvala Buch.-Ham.), a fast growing medicinal tree species, has been successfully micropropagated under in vitro conditions. Direct multiple shoots were regenerated from nodal explants on Murashige and Skoog’s (MS) medium, solidified by agar and supplemented with 1 mg/L 6-benzyl amino purine (BAP) and 0.5 m...