Hostname: page-component-78c5997874-4rdpn Total loading time: 0 Render date: 2024-11-03T01:25:50.374Z Has data issue: false hasContentIssue false
  • English
  • Français

Acid phosphatase localization in endocytosed horizontal cell gap junctions

Published online by Cambridge University Press:  02 June 2009

Dana K. Vaughan  and
Eric M. Lasater
Dana K. Vaughan
Affiliation:
Department of Physiology and Department of Ophthalmology, University of Utah School of Medicine, Salt Lake City
Eric M. Lasater
Affiliation:
Department of Physiology and Department of Ophthalmology, University of Utah School of Medicine, Salt Lake City
Get access Rights & Permissions [Opens in a new window]

Abstract

Gap junction (GJ) endocytosis appears to be part of a cycle of GJ renewal in horizontal cells of the teleost fish retina. At least three stages of GJ endocytosis in these neurons have been identified using conventional electron microscopy (EM): invagination of GJ membranes (GJ blebs); free GJ vesicles; and GJ vesicle fusion with mature lysosomes (Vaughan & Lasater, 1990a). In the present study, EM-level acid phosphatase (AP) histochemistry of white bass retina was used to determine at what stage enzymatic degradation of endocytosed GJs begins. Electron-dense AP reaction product was observed within the trans face of the Golgi apparatus, mature lysosomes, and occasional, internal GJ vesicles. In contrast, GJ blebs, peripheral GJ vesicles, and most internal GJ vesicles lacked AP reaction product. These results support the idea that at least some of the GJ vesicles observed within these retinal neurons arise from endocytosis, are on a degradative pathway, and can be termed GJ “endosomes.” Furthermore, GJ vesicles appear to be initially free of AP, but some later acquire it (presumably from transport vesicles bearing degradative enzymes). It is still unclear whether our previous report of GJ vesicle fusion with mature lysosomes is a subsequent step in GJ degradation or part of a different degradative pathway altogether.

Keywords

Acid phosphataseDegradationEndocytosisGap junctionHorizontal cellLysosomeNeuronRetina
Type
Short Communication
Information
Visual Neuroscience , Volume 8 , Issue 1 , January 1992 , pp. 77 - 81
Copyright
Copyright © Cambridge University Press 1992

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Alberts, B., Bray, D., Lewis, J., Raff, M., Roberts, K. & Watson, J.D. (1989). Molecular Biology of the Cell, 2nd edition, New York: Garland Publishing Inc.Google Scholar
Bennett, M.V.L., Barrio, L.C., Bargiello, T.A., Spray, D.C., Hertzberg, E. & Sáez, J.C. (1991). Gap junctions: New tools, new answers, new questions. Neuron 6, 305–320.CrossRefGoogle ScholarPubMed
Kaneko, A. (1971). Electrical connections between horizontal cells in the dogfish retina. Journal of Physiology 213, 95–105.Google Scholar
Larsen, W.J. & Tung, H.-J. (1978). Origin and fate of cytoplasmic gap junctional vesicles in rabbit granulosa cells. Tissue and Cell 10, 585–598.Google Scholar
Marc, R.E., Liu, W.-L.S. & Muller, J.F. (1988). Gap junctions in the inner plexiform layer of the goldfish retina. Vision Research 28, 9–24.CrossRefGoogle ScholarPubMed
Schmied, R. & Holtzman, E. (1987). A phosphatase activity and a synaptic vesicle antigen in multivesicular bodies of frog retinal photoreceptor terminals. Journal of Neurocylology 16, 627–637.Google Scholar
Spurr, A.R. (1969). A low-viscosity epoxy resin embedding medium for electron microscopy. Journal of Ultrastructure Research 26, 31–43.CrossRefGoogle ScholarPubMed
Vaughan, D.K. & Lasater, E.M. (1990a). Renewal of electrotonic synapses in teleost retinal horizontal cells. Journal of Comparative Neurology 299, 364–374.Google Scholar
Vaughan, D.K. & Lasater, E.M. (1990b). Glial and neuronal markers in bass horizontal and Müller cells. Brain Research 537, 131–140.Google Scholar
Witkovsky, P.J., Burkhardt, D.A. & Nagy, A.R. (1979). Synaptic connections linking cones and horizontal cells in the retina of the pikeperch (Stizostedion vitreum). Journal of Comparative Neurology 186, 541–560.Google Scholar
Yamada, E. & Ishikawa, T. (1965). The fine structure of horizontal cells in some vertebrate retinas. Cold Spring Harbor Symposia on Quantitative Biology 30, 383–392.Google Scholar