Ion channels in the sky

Today is January 5, and it happens to be National Bird Day. Sounds a bit like Birthday, doesn’t it? And who doesn’t enjoy celebrating birthdays! So, let’s take a few minutes to celebrate our feathered friends (not without tying in ion channels, of course).

Birds are actually quite important to us. These living descendants of dinosaurs play a vital role in maintaining ecological balance. They control insect and rodent populations, contribute to plant reproduction through pollination and seed dispersal, and serve as crucial indicators of the overall health of an ecosystem. So, when birds aren’t feeling good, that’s a signal that something’s wrong in nature.

Birds have also been a source of inspiration for many innovations throughout history. Think airplanes, drones, innovative building designs, orthopedic materials, and even wind turbine blade designs – birds have influenced a wide variety of fields. Their unique biological traits have also sparked numerous scientific discoveries.

For instance, consider the Emperor penguin’s remarkable cold tolerance. Living in the ice-cold Antarctic region, these penguins happened to possess slightly different TRPM8 cold receptors, which are less sensitive to cold temperatures compared to those in humans. In fact, replacing the TRPM8 in mice with that of a penguin made them remarkably tolerant to cold.

Many migratory birds have the phenomenal ability to navigate using the Earth’s magnetic field. This sense, known as magnetoreception, allows them to undertake long-distance migrations with incredible accuracy. Recent studies suggest that this capability is tied to specific splice isoforms of CaV1.3/CACNA1D and BK/KCNMA1 channels in their inner ear, essential for detecting small electric fields.

Well, while birds are an essential part of our natural ecosystem, there are situations when they can cause harm or become a nuisance – think airports, industrial areas, monuments… So, what do you do if you need to keep birds at a safe distance?

You might think of using non-lethal repellents, but forget about using pepper spray. Birds are indifferent to the pain-producing effects of “hot” chili peppers. The reason lies in the genetic makeup of their TRPV1 capsaicin receptor. Bird and mammalian TRPV1 receptors are quite different, sharing only 68% similarity in their amino acid structure. Consequently, birds’ TRPV1 receptors are sensitive to intense heat but not to capsaicin, the active component in chili peppers. This distinction plays a key role in how pepper plants defend themselves. They deter mammalian predators with the capsaicin, while favoring birds as seed dispersal agents.

So, to effectively keep birds at bay, you might want to look into TRPA1 activators. Natural repellents like methyl anthranilate or pulegone effectively activate the TRPA1 channel, which in birds (unlike in humans) by the way, is activated by heat.

And there you have it! The next time you see a bird soaring in the sky or hear their morning songs, remember there’s a whole world of fascinating biology at play – from their role in our ecosystems right down to their unique ion channels.

Happy Bird Day!