{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,16]],"date-time":"2025-10-16T20:00:09Z","timestamp":1760644809774},"reference-count":0,"publisher":"Rockefeller University Press","issue":"4","content-domain":{"domain":["rupress.org"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[1984,4,1]]},"abstract":"<jats:p>Intramembrane particles (IMPs) of the plasmalemma of mature, synapsing neurons are evenly distributed along the axon shaft. In contrast, IMPs of growing olfactory axons form density gradients: IMP density decreases with increasing distance from the perikarya, with a slope that depends upon IMP size (Small, R., and K. H. Pfenninger, 1984, J. Cell Biol., 98: 1422-1433). These IMP density gradients resemble Gaussian tails, but they are much more accurately described by the equations formulated for diffusion in a system with a moving boundary (a Stefan Problem), using constants that are dependent upon IMP size. The resulting model predicts a shallow, nearly linear IMP density profile at early stages of growth. Later, this profile becomes gradually transformed into a steep nonlinear gradient as axon elongation proceeds. This prediction is borne out by the experimental evidence. The diffusion coefficients calculated from this model range from 0.5 to 1.8 X 10(-7) cm2\/s for IMPs between 14.8 and 3.6 nm, respectively. These diffusion coefficients are linearly dependent upon the inverse IMP diameter in accordance with the Stokes-Einstein relationship. The measured viscosity is approximately 7 centipoise. Our findings indicate (a) that most IMPs in growing axons reach distal locations by lateral diffusion in the plasma membrane, (b) that IMPs--or complexes of integral membrane proteins--can diffuse at considerably higher rates than previously reported for iso-concentration systems, and (c) that the laws of diffusion determined for macroscopic systems are applicable to the submicroscopic membrane system.<\/jats:p>","DOI":"10.1083\/jcb.98.4.1434","type":"journal-article","created":{"date-parts":[[2004,5,14]],"date-time":"2004-05-14T23:04:59Z","timestamp":1084575899000},"page":"1434-1443","update-policy":"http:\/\/dx.doi.org\/10.1083\/jcb.crossmarkpolicy","source":"Crossref","is-referenced-by-count":29,"title":["Components of the plasma membrane of growing axons. II. Diffusion of membrane protein complexes."],"prefix":"10.1083","volume":"98","author":[{"given":"R K","family":"Small","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"M","family":"Blank","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"R","family":"Ghez","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"K H","family":"Pfenninger","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"291","published-online":{"date-parts":[[1984,4,1]]},"container-title":["The Journal of cell biology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/rupress.org\/jcb\/article-pdf\/98\/4\/1434\/1642400\/1434.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/rupress.org\/jcb\/article-pdf\/98\/4\/1434\/1642400\/1434.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,7,24]],"date-time":"2023-07-24T17:26:14Z","timestamp":1690219574000},"score":1,"resource":{"primary":{"URL":"https:\/\/rupress.org\/jcb\/article\/98\/4\/1434\/19883\/Components-of-the-plasma-membrane-of-growing-axons"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1984,4,1]]},"references-count":0,"journal-issue":{"issue":"4","published-print":{"date-parts":[[1984,4,1]]}},"URL":"https:\/\/doi.org\/10.1083\/jcb.98.4.1434","relation":{},"ISSN":["0021-9525","1540-8140"],"issn-type":[{"value":"0021-9525","type":"print"},{"value":"1540-8140","type":"electronic"}],"subject":[],"published":{"date-parts":[[1984,4,1]]}}}