Chloride channels and fainting goats

What a beautiful day today! The sun is shining, and a nice breeze is blowing in your face. You are peacefully sitting on a bench in the park, reading through the latest news on ion channels and transporters. Everything is great, calm, and quiet.

Suddenly, someone from behind runs up to you and loudly shouts, “Bang, boom, bam!!!”

What would be your reaction?

You would probably be somewhat startled, surprised, and maybe even recoil. But, no matter how unpleasant the situation may be for you, your reaction would most likely pale in comparison to the dramatic response of fainting goats.

Also known as myotonic, nervous, or wooden leg goats, these adorable animals react quite spectacularly to attempts to scare or surprise them: their muscles lock up and, in most cases, they’ll fall over, appearing unconscious on the ground. The episode lasts 10-15 seconds, after which the goat gets up and continues wandering as if nothing happened.

Have you seen this impressive reaction? If not, look here: https://www.youtube.com/watch?v=f_3Utmj4RPU

While (sadly enough) many people find it amusing and these goats are in high demand, the poor animals are actually sick.

They suffer from myotonia congenita, a rare genetic disorder caused by a mutation in the chloride channel CLC-1 (CLCN1) in their skeletal muscles.

Yes, skeletal muscles are actually quite unusual in that 70–85% of resting membrane conductance is carried by chloride ions. And the main player here is the CLC-1 channel.

Normally, CLC-1 helps muscle cells relax after contracting, contributing to the repolarization phase of the action potential and suppressing repetitive firing. But in myotonic goats, mutated dysfunctional channels can’t conduct chloride ions properly, meaning the muscles remain contracted longer than they should, causing the dramatic stiffening and falling over seen when the goats are startled.

The study of CLC-1 and myotonia congenita in goats provides valuable insights into similar human conditions. By examining how these chloride channels function, or fail to function, researchers can explore new treatments for muscle disorders in humans. One such new treatment which shows great potential is the CLC-1 inhibitor, NMD670, developed by NMD Pharma for the treatment of myasthenia gravis, an autoimmune disease causing debilitating muscle weakness.

Kudos to these wonderful goats for raising awareness about important medical conditions in such a unique manner. They truly deserve a round of applause. But please, if you do clap, keep it gentle – you don’t want to see them go stiff and hit the ground!