杏吧原创

There is a cure for zombies after all 鈥� if you are a cockroach. A new study has shown that cockroaches that turned into 鈥渮ombies鈥� after being stung by a parasitic wasp can be revived with an antidote.

Cockroaches can lose their ability to walk when stung by jewel wasps (Ampulex compressa) 鈥� the females of which use the cockroaches to feed their young.

The wasp, being much smaller than the cockroach, has evolved a fine sting that can deliver a venom cocktail directly into the cockroach鈥檚 brain. The poisons effectively turn the cockroach into a zombie.

The cockroach is not entirely paralysed, but loses its ability to escape. The wasp then grabs it by the antennae and pulls it into its burrow and lays an egg on its abdomen. The cockroach sits still while the wasp鈥檚 larva hatches, chews a hole into its belly, and slowly eats its living host from the inside over a period of eight days.

Brain injection

To find out if he could revive the cockroaches, from Ben-Gurion University in Be鈥檈r Sheva, Israel, injected stung zombie cockroaches with candidate chemicals that resembled various neurotransmitters in the brain.

Libersat found that one of the drugs, a mimic of the neurotransmitter octopamine, succeeded in bringing the roaches back to life.

鈥淭he cockroach begins to walk spontaneously again, especially when injected directly into the brain,鈥� says Libersat.

He had previously discovered that octopamine-producing neurons elsewhere in the cockroach鈥檚 body show reduced activity when stung by the wasps. Libersat thinks that the same thing may happen in the brain.

Zombie humans

鈥淚 think the most likely explanation is that a component of the toxin affects the expression of genes that regulate the activity of these neurons鈥�, he says.

So could octopamine become a possible antidote for future humans turned into zombies by, say, invading aliens? Not quite, says neuroscientist Hans-Joachim Pfl眉ger at the Freie Universit盲t Berlin, Germany.

鈥淥ur brain is of course much more complex, and we use different neurotransmitters,鈥� he says. 鈥淏ut new research shows tiny quantities of octopamine exist in the vertebrate spinal cord and do affect leg movement, so it will be interesting to see what exactly octopamine does in humans.鈥�

Journal reference: (vol 210, p 4411)