The Devastating Loss of Tongue Dexterity

With my recent toxic plant preoccupation, I have received an assortment of interesting anecdotes including one regarding the yellow star thistle.

Horses that forage on the tall spiny yellow flower die of starvation. Under the impression that the plant causes an obliteration of appetite, my interest was piqued -especially since my second current preoccupation is how the brain responds to food in the satiation/hedonistic sense.

The disease, following ingestion of this nasty invasive, is called equine nigrapallidal encephalomalacia (how much tongue dexterity do you need to say that?). While the cause of death is starvation (or dehydration), loss of appetite is not the reason. It turns out that the plant's toxins result in brain lesions in areas having nothing to do with detecting food volume, taste or calories; they have to do with fine motor control. For a horse, the only thing that requires intricate movement ability is the tongue.


Moret et al. 2005
Sander et al. 2001