Experimental tests of quantum effects in cytoskeletal proteins/Memory and microtubules

Posted by Simon Raggett on 26 March 2009 | 0 Comments

Tags: Physics

This very briefly summarises a chapter by Andreas Mershin et al of the MIT Centre for Biomedical Engineering published in ‘The Emerging Physics of Consciousness’ in 2006. Mershin’s interest here is information based processing in protein, particularly the tubulin proteins that make up the microtubules. These latter are proposed as the basis for quantum features in the brain in the Penrose/Hameroff (Orch OR) theory of consciousness. Mershin emphasises that proteins are the work horses of living matter, and are involved in signalling, energy transduction, movement and catalysis of reactions.

In a study with fruit flies, Mershin et al showed that when microtubules and microtubule associated proteins (MAPs) were slightly disturbed, the olfactory memory of the flies was impaired. This was taken to indicate that microtubules had a role in memory and probably also in information processing.

Other tests demonstrated a high dipole moment in the tubulins. Models of quantum activity in microtubules depend on the dipole moment of the tubulin. The ordering of electrical dipoles in the tubulin is suggested to be due to dipoles in surrounding water. The behaviour of dipoles under such conditions is the basis for predictions of quantum superposition and also quantum entanglement.

Mershin is highly critical of the often quoted Tegmark (2000) paper attacking the Penrose/Hameroff model. Mershin’s main objection is that Tegmark failed to allow for the possibility of the interiors of the microtubules being isolated from the environment.

References:

Mershin A. et al (2004) - Learning and Memory, 11 (2), pp. 277-87
Mershin A. et al (2004) - Biosystems, 77, pp. 73-85

Simon Raggett