Dolphins are pretty amazing creatures, to put it simply. In Douglas Adams’ The Hitchhiker’s Guide to the Galaxy, the dolphins knew of the Earth’s impending doom well before people did (“So long, and thanks for all the fish!”). In addition to their extraordinary cognitive abilities, they have highly developed and extremely interesting social skills (such as killing for pleasure).

Speaking of killing, let’s discuss sharks. Contrary to popular belief, sharks are only dangerous if you give them reason to be. During the course of my summer internship, I’ve seen many sharks, from toothless dogfish to five foot long juvenile tiger sharks. All have been docile; they tend not to try to attack unless you poke them hard enough (in an out of water case). But, say you happened to be standing in front of the aforementioned tiger shark’s mouth and poked it, and it flailed and bit your leg. You’d probably scream in pain, bleed, and need to see a doctor right away.

Now consider an in water encounter between a dolphin and a shark. The dolphin could just be swimming normally and pass a shark. The shark could misinterpret the dolphin swimming nearby as a threat, and attack, leaving a 3 centimeter deep, 30 centimeter long, 10 centimeter wide wound. Not only would the dolphin not feel pain from this, but it would continue feeding, swimming, and behaving normally! Even more amazingly, the wound would heal over time with little scarring or changes in overall contour!

Wound healing over time in a bottlenose dolphin

Wound healing over time in a bottlenose dolphin

A recent study by Zasloff investigated the remarkable healing process in bottlenose dolphins. Though little is known about the pain reflexes in dolphins, it has been shown that they will withdraw when pricked. In response to long lasting wounds caused by shark attacks, dolphins have been observed to exhibit normal swimming and feeding behaviors in as little as two days after the attack. They do not seem protective of their wounds in the slightest either. What is it about the dolphin’s pain circuits allows them to seemingly ignore serious wounds?

The biological and biochemical healing process is likely due to special adaptations resulting from a marine lifestyle. Dolphin wounds may be less likely to bleed due to a diving reflex adaptation. When diving, dolphins divert their blood supply to their inner vital organs, allowing them to spend longer periods of time underwater. This reflex might also come into effect after sustaining a traumatic wound. However, what makes the process truly remarkable is that it mimics the process of regeneration. Just like a starfish can regrow an arm, this process allows deep wounds to heal almost flawlessly in dolphins. Blubber invades the wound and repairs the tissue with the already existing blubber structure. In addition, blubber contains both natural organohalogens and short chain fatty acids known as isovaleric acids, both of which serve as antibacterial agents. Given the amount of bacteria in the marine environment, these must be extremely effective against preventing infection in the wound.

Not meaning to wish harm on dolphins, but studying their wound healing process could give tremendous insight into how humans can successfully manage injuries. We could potentially produce numerous new painkillers or antibiotics if we found the right chemicals in dolphins. Studying the regeneration-like healing may lead to new discoveries in stem cell research. Though we probably still will not be able to regrow limbs, the field has immense potential in treating localized but serious wound injuries.

Observations on the Remarkable (and Mysterious) Wound-Healing Process of the Bottlenose Dolphin : Letter to the Editor, Journal of Investigative Dermatology

Synesthesia is a neurological condition which joins sensory perceptions. The most common variety links numbers and letters (and often words like the days of the week) with colors. However people with synethesia can experience a slew of unique sensations ranging from tasting shapes to seeing sounds.

In neurologist Richard Cytowic’s book, ‘The Man Who Tasted Shapes’, a synesthetic dinner host describes his experiences: “When I taste something with an intense flavor, the feeling sweeps down my arms into my fingertips. I feel its weight, texture, [temperature], everything. I feel it like I’m actually grasping something.” For him, the taste and aroma of a meal elicit a strong tactile sensation.

Before extensive studies had been conducted on this condition, accounts of synathetic experiences were viewed as out-of-the-ordinary imaginative metaphors and not taken seriously. But in recent years Cytowic has heavily researched synesthesia and has determined its diagnostic criteria, the most significant being that these mixed perceptions are involuntary and automatic.

Tests such as the one below have shown to prove the case.  When the image to the left is presented to an individual without the condition, he/she considers it slightly difficult to distinguish the 5’s from the 2’s. Synesthetes (in particular those with a number-color association) can almost seamlessly make the distinction between the numbers due to the specific colors which they may have come to innately pair with them (as the image on the right shows, the synesthete associates 5 with green and 2 with red).

There have been multiple theories for synesthesia. A popular one suggested that it was caused by neural “cross-wiring” between interpretive areas. For example, a color processing region in the brain’s visual cortex called V4 lies adjacent to an area responsible for identifying letters and numbers, and a mixed perception of color and letters/numbers could be attributed to cross activation between these areas.

However,  Cytowic and his collegue David Eagleman propose a better hypothesis: that the neurological condition is really caused by a slight difference in the balance of excitation and inhibition. When chemical inhibitors, which repress other types of processing during a specific sense experience, are blocked, it is possible to sense blue from a red object without any contradiction. This theory was put forward because we know that non-synesthetes can aquire synethesic “symptoms” under the influence of psychoactive drugs like LSD.  So, we’re all capable of producing unnatural sensory combinations, but a lucky few of us can do it everyday.

The Man Who Tasted Shapes by Richard E. Cytowic

Dr. Richard E. Cytowic’s Website

Neurocognitive Mechanisms of Synesthesia