Best of Buds

No, it is not my birthday, this is my cake from a birthday long (less than two years) past. Now, I am not a lady usually tempted by fancy cheesecake concoctions. Not really a lady in the first place. But if I saw pina colada or mint choco-brownie or raspberry-mocha-berry-fudgestravaganza cheesecake on a menu I’d typically reply with a scowl and a violent crossing of arms. So it is shocking I even considered hot buttered rum cheesecake. But consider it I did. Besides devouring and digesting it. This was not some weak cheesecake with delusions grandeur of being a dessert drink, this was hot buttered rum reincarnated as a cheesecake for good deeds in its previous life. It was glorious.

My supreme enjoyment was all thanks to gustation. We all should thank our sense of taste; life would be a lot paler without the many tastes of our body fuel. Out would go birthday cake, fanciful cocktails, wine tasting and Cheezits. Spinach with bleu cheese salads, chocolate and mango juice would all be gone with the wind. We would just eat bizarre mashes of what’s good for us and enthusiastically tolerate it all. So then thank GOD AND ALL THAT IS HOLY for taste buds.

You have about 9000 taste buds and despite all the hype about them being color-coordinated taste microphones, they are a bit more complex than that. But just a bit. Taste buds are not the little nubbins all over your tongue, but the taste cells bordering the nubbins are the ones that really work the gustatory magic. The buds are composed of receptor cells and supporting cells. Receptor cells are modified epithelial (inner skin) cells that possess many folds to allow as much taste juice onto them as possible. This “tasting site” is the taste pore. Molecules and ions in the macerated food bind to the pore and results in a chain reaction: the receptor cells provoke an action potential (Remember action potentials?) in connecting nerve fibers and the brain in eventually alerted to the presence of tastiness (or not).

So what triggers this response? Well, it depends. Humans can taste sweet, salty, sour, bitter and meaty things and each have different ways to excite your senses. I will address this is detail tomorrow, but for now I will add that spicy is not a taste. It is your taste buds crying for a ceasefire.

Source

Sherwood, Lauralee, Hillar Klandorf and Paul Yancey. 2005. Animal Physiology: From Genes to Organisms. Thomson Brookes/Cole, Belmont, CA.

Photo credit me. Cheesecake credit, Kensie Steakhouse.

Magneto is Real and He’s a Shark

If you’re great big nerd like I am and enjoy X-Men comics and/or Sir Ian McKellan, you have probably had some form of the “Mag-neat-o” vs. “Mag-net-o” debate. If you’re not a big nerd and have no idea what I’m talking about, well then get off the internet and go clubbing or something! Skateboard with your hat on backwards, I don’t know, jeez. Whatever it is you cool kids do these days. You could also just smile, nod and keep reading. Anyway, the debate can end! Mag-neat-oreception, the ability to detect the Earth’s magnetic field, is a thing. You’re all so relieved, right? Right.

Although not well studied, magnetoreception is not uncommon. Found in anything from bacteria to bugs to birds to batrachians, this extra sense involves magnetite (an iron oxide mineral) crystals that, when arranged in chains, can align with the Earth’s magnetic fields and allow animals to use those fields in navigation (though there is a receptor involved, the exact mechanism is unknown). Migratory birds and sea turtles are excellent examples of such magnetic navigators. Sadly, they cannot use their magnetoreception to move bridges, but I am sure they’re working on it. Just like we’re working on HOW those suckers use specialized receptors to receive and comprehend the magnetic field data from the magnetite crystals, then use this to solve projected needs (do they need to find breeding grounds? Food?).

Elasmobranchs (sharks, rays and skates) also use magnetoreception, but the sensory organ involved is very different. They use ampullae of Lorenzini (tiiiny holes filled with a salty gel) to sense when prey pass over magnetic fields. But those little ampullae are not only for magnetoreception alone, oh no. Consider the hammerhead shark. Besides being impractical for normal doorways, it is a master of electroreception. That big hammer-shaped head is COVERED with ampullae of Lorenzini for detecting even the electrical signals of a buried fish’s gills. Since the receptors at the bottom of the ampullae respond to voltage variation disturbing the gel, they are also thermosensitive. Nowhere to hide from these badasses. Except land, I’d try land.

Source

Sherwood, Lauralee, Hillar Klandorf and Paul Yancey. 2005. Animal Physiology: From Genes to Organisms. Thomson Brookes/Cole, Belmont, CA.