Those injected with a chemical that blocks octopamine, however, show a reduction in spontaneous walking, much like the victims of the wasp sting. Libersat has shown that unstung cockroaches injected with an octopamine-like compound show an increase in walking behaviour.
The venom of the second sting blocks the receptors for another neurotransmitter called octopamine, which is involved in the initiation of spontaneous and complex movements such as walking. It is the second sting that turns the cockroach into a zombie, and contains what Frederic Libersat and his colleagues at Ben Gurion University refer to as a “ neurotoxic cocktail”. This prevents the cockroach from escaping while the wasp inflicts the second, more toxic sting directly into the roach’s brain. GABA is a neurotransmitter that blocks the transmission of motor signals between nerves, and, together with the other two chemicals, it temporarily paralyses the cockroach’s front legs. The first sting, administered to a mass of nerve tissue in the cockroach’s thorax, contains large quantities of gamma amino butyric acid (GABA), and complementary chemicals called taurine and beta alanine. This wasp-cockroach relationship has been documented as early as the 1940s, but it wasn’t until recently that scientists have been able to understand how exactly the wasp pulls off this precise behavioural manipulation.
0 kommentar(er)
