My favorite study of the week says dogs have about 530 million cortical neurons, and cats have 250 million. However, cats make up the deficit by forcing their owners to boast about feline superiority. Here are some other tidbits that caught my attention this month.
1) “Visual Impairment Intracranial Pressure Syndrome”
If you travel to space you’ll probably need to take your brain, and if you remain in microgravity long enough your brain might migrate toward the top of your cranium like a party balloon hitting the ceiling. It turns out that ain’t great. There are ways to contract this problem on earth if you’re so inclined.
2) Let’s Celebrate GABA
Gamma Aminobutyric Acid (GABA) doesn’t get much press, but it’s one of the brain’s most widespread neurotransmitters. It serves mainly to inhibit signals. Cambridge researchers have recently associated it with the vital ability to inhibit thought. Too little GABA in the hippocampus appears to contribute to problems like rumination and even hallucinations.
On a related note, alcohol is thought to imitate GABA, which might explain why an intoxicated prefrontal cortex has difficulty inhibiting cringe-worthy behavior. Also related, regular exercise appears to help the brain regulate GABA and its excitatory counterpart, glutamate—at least in rats.
3) Viva Las Vagus!
In France, a man in an extended vegetative state has shown signs of consciousness after vagus nerve stimulation (VNS). The vagus nerve is a massive pathway with projections into the gut, heart, and other organs. Researchers have been tinkering with VNS for conditions like epilepsy and treatment-resistant depression, but restoring consciousness through VNS seems to me like starting a car by yanking on the headlight wires. The brain is an endlessly fascinating place.
4) SSRIs Affect More Than the Brain
Taking an SSRI is a weightier decision than most people realize. Sometimes it’s the best option but there are serious tradeoffs, and researchers are now noticing unfortunate bodily effects outside the brain. “By blocking either the serotonin transporter or the norepinephrine transporter, antidepressants prevent cells in crucial organs from taking up these biochemicals the way they normally do.” Not to sound like a broken record, but exercise is great for depression and “crucial organs.”
5) Dogs Feel Your Anger
This study found dogs lick their mouths in response to angry human faces, though less-so in response to angry human vocalizations. The mouth-licking response is also stronger for human faces than for dog faces. This article is worth reading just for the videos. The researchers produced a higher-than-average cuteness index.
I hope your holidays are warm and happy! Until next time.