Joseph W Vanable

Purdue University | Purdue · Department of Biological Sciences

The strength of the electric fields in the vicinity of 1.5 mm circular lesions in the bovine cornea has been found to influence the rate of re-epithelization. A decrease in the field strength by submersion of the lesions or by treating the lesions with the Na+-channel blocker, benzamil, significantly retarded healing. An increase in the field stren...

There is convincing evidence that endogenous electric fields are necessary for normal wound epithelization, but it is unclear whether normal epithelization rates can be accelerated increasing normal field strengths. Although we confirmed that normal lateral fields are required for normal Notophthalmus viridescens epithelization rates, significant i...

A lateral potential drop along the outer surface of the cornea could be measured at the edge of wounds made in the corneal epithelium of the isolated bovine eye when the cornea was covered by simulated tear film of modified Hanks' solution. These lateral fields (LFs) had an average magnitude of 42 +/- 1.4 mV mm-1 in the first 0.25 mm from the wound...

The lateral electric fields (LFs) in the vicinity of small wounds made in hindlimb digit tip skin of Notophthalmus viridescens have been measured and manipulated. Healing of these wounds was assessed by crystal violet staining and by histology. Paired experiments were conducted on the animals: the healing of one digit's wound was compared with heal...

Wounded amphibian skin heals initially by a migration of epithelial cells from the cut edge towards the center of the wound. The density of currents leaving wounds made in Notophthalmus viridescens skin was manipulated in order to determine whether electrical fields associated with these currents might have a significant role in promoting this cell...

The transepithelial potential (TFP) across the skin of Notophthalmus viridescens hindlimb digits was measured in animals immersed in artificial pond water (APW) that was 1.5 mM in NaCl, 0.06 mM in KCl, and 0.1 mM in CaCl2, before and after making a wound in the digit tip. Before wounding, the TEP of the digit skin averaged 35.3 mV ± 5.5 mV (S.E.M.)...

Retinal projections to the pretectal and terminal accessory optic nuclei were studied in normal wild-type mice and mutant mice with abnormal optokinetic nystagmus (OKN, Mangini, Vanable, Williams, and Pinto: J. Comp. Neurol. 247:191–209, '85). The mutants used were (1) pearl, which exhibits an inverted OKN in response to stimulation of only the tem...

There is evidence, mostly from in vitro experiments, that electric fields can affect the behavior of cells. However, very few direct measurements of fields have been made in vivo, making it difficult to judge whether there is any possibility that normal fields could have significant biological effects. Using microelectrode penetrations through the...

Following amputation of urodele limbs, large electric currents leave the stump surface. These currents are initially high and decline to low levels within a few days following amputation (R. B. Borgens, M. E. McGinnis, J. W. Vanable, Jr., and E. S. Miles (1984). J. Exp. Zool.231, 249–256). Using Notophthalmus viridescens, we examined whether this d...

We have previously investigated the relevance to limb regeneration of epidermally driven, Na+-dependent limb stump currents by blocking epidermal Na+ channels with amiloride, 3,5-diamino-6-chloro-N-(diaminomethylene)pyrazinecarboxamide. In order to reduce Notophthalmus viridescens stump currents more effectively than with amiloride, we have examine...

We tested the optokinetic nystagmus (OKN) reflex of various hypopigmented mutant mice and ultrastructurally examined the pigmentation of various ocular structures in these mutants. Using electron microscopy we examined the pigmentation of the choroid and retinal pigment epithelium (RPE) and measured the numerical density, volume density, and distri...

The authors screened various inbred strains and mutants of the mouse, Mus musculus, for qualitatively abnormal or reduced numbers of optokinetic nystagmus (OKN) eye movements. Thirteen hypopigmentation mutants and ten neuromuscular mutants were found to have abnormal or markedly reduced OKN, but none of these mutants had retinal degeneration. Ten o...

We report here that a variety of salamanders and newts from differing habitats all drive a steady ionic electric current out of the forelimb stump tip after forelimb amputation. Several hours after amputation the density of this stump current ranges from about 10 to 100 μA/cm2 in most species, and declines with time. In most cases, the magnitude of...

There are many points of view from which one may consider the healing of wounded skin, several of which are dealt with in earlier chapters. We would like to focus on one aspect of wound healing that has received only scant attention: the possible role of electric fields in the migration of epithelial cells that must occur in order to heal wounded s...

Voltages across various glabrous (and gland-free) regions of cavy skin range from 30 to 100 mV, inside positive; across hairy ones, 0 to 10 mV. (moreover, hairy areas also tend to maintain lower transcutaneous voltages in man.) When an incision is made through the glabrous epidermis of the cavy, a microampere flows through each millimeter of the cu...

Voltages across various glabrous (and gland-free) regions of cavy skin range from 30 to 100 mV, inside positive; across hairy ones, 0 to 10 mV. (moreover, hairy areas also tend to maintain lower transcutaneous voltages in man.) When an incision is made through the glabrous epidermis of the cavy, a microampere flows through each millimeter of the cu...

Mice of the mutant strain pearl (pe/pe) differ from the wild strain by a single gene mutation, which leads to a lightening of the coat color. We tested this strain to see if this mutant gene also expressed itself in one or more visual abnormalities. Pearl mice were found to lack totally the optokinetic nystagmus reflex that was present in every nor...

The trochlear nerve of Xenopus laevis larvae was sectioned in the orbit, and the nerve distal to the section was removed, so that it could not serve to guide the return of the regenerating nerve to the superior oblique muscle (SOM). In a second series, in addition to removing the distal nerve segment, the SOM was removed or damaged. The regeneratio...

We have asked the question whether the natural electric currents which leave urodele limb stumps are in any way needed for their regeneration. As an initial test, we have greatly reduced such currents in the tiger salamander, Ambystoma tigrinum, by applying 0.5 mM amiloride to the stump skin or by immersion of the animals in sodium depleted media....

A wide variety of developing systems drive large steady electric current through themselves. In particular, the stumps of amputated amphibian limbs drive large currents out their cut ends. The effects of modulating these stump currents suggest that they help initiate regeneration.

Large, uniform, skin-driven currents (20–40 μamp/cm2) leave the ends of limb stumps of post-metamorphic frogs (Rana pipiens) from about the first through the tenth day after amputation. However, right after amputation, while currents of comparable density may leave the periphery of the cut surface, current densities are greatly depressed in the cen...

A steady, small (0.1 μA) current was artificially pulled out of the end of the stumps of amputated adult Xenopus forelimbs for three to four weeks. Six months to a year later, the following responses were observed: 1. Some stimulated regenerates formed broad, flattened bifurcated structures, while sham‐treated controls formed typical hypomorphic sp...

Electrical currents near regenerating newt limbs were measured with a recently developed vibrating probe. Steady currents with local surface densities of 10 to 100 muA/cm2 or more leave the end of the stump during the first 5-10 days after amputation and are balanced by currents with densities of only 1-3 muA/cm2 that enter the intact skin around t...

We have applied 0.2 μamps of current to the forelimb stump of Rana adults for several weeks. The stimulator was designed to avoid introduction of any physiologically active electrode products into the tissue. Current was applied to the dorsal postaxial region of the stump. Cathodal (i.e., distally negative) current initiated partial regeneration; a...

Visually evoked eye movements were observed and measured in one inbred strain of the mouse (C57BL/6J) and in one inter-strain hybrid. This was done by observing pupillary movements while a mouse was restrained inside of a test apparatus that presented the mouse with slowly moving stripes and allowed the experimenter to view the mouse's pupil using...

As the number of multicellular mucous glands increases in the skin ofXenopus laevis larvae during metamorphosis, the acid mucopolysaccharide (AMPS) content of the skin increases also. Purification of this skin AMPS by polyacrylamide gel electrophoresis revealed a major band characteristic of adult mucous secretion. Incorporation of14C-galactose int...

As the number of multicellular mucous glands increases in the skin of Xenopus laevis larvae during metamorphosis, the acid mucopolysaccharide (AMPS) content of the skin also increases. Purification of this skin AMPS by polyacrylamide gel electrophoresis revealed a major band characteristic of adult mucous secretion. Incorporation of ¹⁴C galactose i...

After sectioning N IV in Xenopus laevis larvae, in addition to the regeneration of that never to the superior oblique muscle (SOM), sprouts form from N III, chiefly from the branch supplying the inferior oblique muscle (IOM). these were shown to innervate the SOM by methylene blue staining, silver and zinc iodide-osmium impregnations, and electrica...

Changes in activity and subcellular distribution of acid phosphatase isozymes of the Xenopus laevis tadpole tail were investigated. Enzyme activities per tail were quantified by assay of Sephadex G-75 eluates containing the phosphatases, using p-nitrophenylphosphate as substrate. Differential centrifugation of isotonic homogenates revealed no large...

Approximately 3.5 days before rudiments with ca. 5 or more cells (recognizable rudiments) appear in Xenopus forelimb skin during metamorphosis, there is an increase in the frequency of mitosis in the epidermis of this skin. Subsequent to this increase in mitosis, but prior to the appearance of recognizable rudiments, doublets of contiguous mitotic...

Dorsal head and trunk skin of Xenopus laevis larvae has been cultured for 6 to 7 days in liquid medium on a Rollordrum in order to study its ability to develop glands while in relative isolation.We have found that in this skin, whether it is cultured in control medium (which could contain as much as 2 mμg thyroxin/ml, contributed by the serum in it...

The development of subepidermal granular glands of Xenopus laevis larvae during metamorphosis has been described morphologically and biochemically.It was found that as metamorphosis progresses, mature granular glands become more and more numerous in the skin, and that along with this increase in granular secretion, the 5-hydroxytryptamine (5-HT) co...

The conditions for the reaction of Jepson and Stevens (1) have been altered so that small amounts of 5-hydroxytryptamine (5-HT) reacted with ninhydrin can be assayed fluorometrically in solution. As measured with a 1P21 photomultiplier tube, the fluorescence of the compound formed in this reaction exceeds that of 5-HT alone at pH 4.0. The positions...

Hydroxyproline and some other amino acids in hydrolysates and dialysates of four stages of developing larvae (eggs, gastrula, prism and pluteus), and in two tissues of the adult forms of Strongylocentrotus dröbachiensis were separated by chromatography on an ion-exchange resin and were assayed colorimetrically.It is concluded that free hydroxyproli...