A theory of gravikinesis in Paramecium

The archaic eukaryote unicellular microorganism, Paramecium, is propelled by thousands of cilia, which are regulated by modulation of the membrane potential. Ciliates can successfully cope with gravity, which is the phylogenetically oldest stimulus for living things. One mechanism for overcoming sed...

Full description

Saved in:
Bibliographic Details
Published in:Advances in space research 1996, Vol.17 (6), p.11-20
Main Author: Machemer, H
Format: Article
Language:English
Subjects:
Animals
Cilia
Electrophysiology
Gravitation
Gravity Sensing - physiology
Mathematics
Mechanoreceptors - physiology
Membrane Potentials - physiology
Models, Biological
Motor Activity - physiology
Orientation - physiology
Paramecium - physiology
Space life sciences
Swimming
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The archaic eukaryote unicellular microorganism, Paramecium, is propelled by thousands of cilia, which are regulated by modulation of the membrane potential. Ciliates can successfully cope with gravity, which is the phylogenetically oldest stimulus for living things. One mechanism for overcoming sedimentation is negative gravitaxis, an orientational response antiparallel to the gravity vector. We have postulated the existence of a negative gravikinesis in Paramecium, i.e. a modulation of swimming speed as a function of cellular orientation in space. With negative gravikinesis, an upward oriented cell actively augments the rate of forward swimming and depresses active locomotion during downward orientation. A brief outline of the gravikinesis hypothesis is given on a quantitative basis and experimental data are presented which have confirmed the major assumptions.
ISSN:0273-1177
1879-1948
DOI:10.1016/0273-1177(95)00607-G