In preparation for my trip to the Caribbean next semester, I spent this weekend taking a class to learn how to SCUBA dive. My class and I learned all about the necessary equipment, what to do in emergency situations, and how to stay safe while SCUBA diving. We also learned about the physics of pressure, volume and density, so that we could better understand what happens when you descend into the deep. This inevitably led to a conversation about Nitrogen narcosis.
Nitrogen narcosis, or “rapture of the deep”, is a condition in which the symptoms resemble those due to intoxication by alcohol. Divers experiencing nitrogen narcosis lose their decision making abilities, their focus, and their judgment, coordination and multitasking skills become impaired. What could this potentially mean for the diver? They could ignore safe diving practices because they feel invulnerable to the dangers of their surrounding environment (sounds a bit like the actions of those individuals who are intoxicated by alcohol).
While the mechanisms of narcosis are not fully understood, it is believed that the change in pressure due to depth has an impact on it (most cases are not reported until descent around 100 feet, and immediate relief from symptoms can be acquired simply by ascending a few feet). Nitrogen dissolves more slowly in the blood than other gases, which is thought to affect the permeability of the lipid bilayers of neural cells. The Meyer-Overton hypothesis states that narcosis is due to Nitrogen gas penetrating the lipids of the neural cells, which is thought to interfere with the transmission of neural cell signals. Further research has indicated that the gas induces an increase in volume of the bilayer, which disrupts the membrane environment and modifies cell responsiveness.
Luckily for me, I am only certified to dive to 60 feet, so I shouldn’t experience any complications due to Nitrogen narcosis. I’ll just play it safe and get drunk off alcohol instead.
Lavoute, C., Weiss, M., Rostain, J-C. 2005. Effects of repeated hyperbaric nitrogen-oxygen exposures on the striatal dopamine release and on motor disturbances in rats Brain research 1056(1):36-42.
Schwerzmann, M., Seiler, C. 2001. Recreational scuba diving, patent foramen
ovale and their associated risks Swiss Medical Weekly 131:365-374.