2 PLATEAU MODULI FOR ACTIN GELS

Conflicting experimental results have been reported for the plateau mo dulus in actin solutions: Analogies are often made with the viscoelast ic, behavior of flexible polymers making use of the idea of entangleme nt as the source of the macroscopic storage modulus. We resolve appare nt experimental and theoretical contradictious by pointing out the pos sibility of two distinct plateau regimes as a function of frequency in semidilute solutions of semiflexible polymers. We make the point that longitudinal and transverse hindrance can have very different effects at the macroscopic scale.