Tripping on ketamine lifts depression in fish

The dissociative "psychedelic" drug Ketamine has shown to be helpful at relieving depression in zebrafish. The new scientific study by Harvard researchers could increase our understanding of how ketamine works in the human brain to alleviate depression and eventually lead to possible new therapies. Of course, the first question is what does depression look like in a fish?

"We can make the fish think it's swimming against a current by showing it a visual stimuli that makes it think it's moving even though it's actually stuck in place, and the fish will move its tail to fight the current," explains graduate student Marc Duque Ramirez. "[In previous work, our lab] showed that if you switch from that to making the fish think its swims don't work anymore, it goes from swimming happily to getting stressed and struggling and then giving up." 

From Harvard:



[In this new experiment,] they treated the fish by adding ketamine to the water. The drug initially has a strong dissociative effect that prevents normal swimming, so the researchers would wait an hour before placing the zebrafish in the futility assay. They found that ketamine-treated fish took much longer to give up compared to controls. 

Whole brain imaging revealed that the ketamine-treated fish were experiencing huge surges of calcium in the astrocytes in the hindbrain. Duque Ramirez and his colleagues believe the calcium surge is essentially causing adaptation in the circuit that dampens its excitability, so that going forward, it delays or even eliminates the giving up behavior[…]

Duque Ramirez adds that since whole brain imaging and behavioral assays are much easier in translucent larval zebrafish than in mice, zebrafish assays could be used as a first pass for testing and screening novel antidepressants. 

As The Beatles sang, "turn off your mind, relax, and float downstream…"

Previously:
• Doctors describe what it's like giving ketamine to patients: apparently Enya helps
• Ketamine helps depressed patients temporarily experience pleasure again
• Dissociative psychedelic Ketamine may help suicidal children
• Dr. Bronner's soap company is now offering ketamine therapy to its employees