Thy-1 cell-surface glycoprotein


Mice lacking the cell adhesion molecule Thy-1 fail to use socially transmitted cues
to direct their choice of food


[Research Paper]
Veronique Mayeux-Portas, Sandra E. File, Colin L. Stewart, Roger J. Morris
Current Biology 4 January 2000, 10:68-75.



Thy-1 is a major cell-surface glycoprotein of mature neurons and certain other cells,
including those of the lymphoreticular system. Despite being the simplest member of
the immunoglobulin superfamily, the biological role of  Thy-1 has proved elusive.
Analysis of  Thy-1 null mice has shown the presence of excessive GABAergic
inhibition of neurotransmission in the dentate gyrus of the hippocampal formation
selectively, without any neurological or behavioural effects being apparent.

We show here that Thy-1 null mice are unable to make the appropriate dietary choice

in the test for social transmission of food preference, despite showing a normal level
of social interaction with the demonstrator mouse, normal neophobia, and normal 
learning in a T-maze using scented food as cues. The mice also performed normally in
tests of anxiety, locomotor activity, exploration of a novel environment, habituation to  
novelty and spatial learning. This phenotype is maintained on two different strain
backgrounds, is rescued by transgenic expression of  Thy-1 and by administration of
the GABAA receptor antagonist pentylenetetrazole.
The test for social transmission of food preference is based on the normal ability of mice
in a colony to learn from each other which foods are safe to eat. The lack of this key
survival behaviour in Thy-1 null mice could act as an evolutionary pressure point to
conserve expression of  Thy-1. Furthermore, the specific cognitive defect caused by
inactivation of the Thy-1 gene suggests that it would be worthwhile to determine the 
role of  Thy-1 in certain human familial forms of mental retardation that map to 
chromosome 11q22-23 in the region of the Thy-1 locus rather than the nearby
ataxia telangiectasia locus.