Brains of bee scouts

OUTLIERS Thrill-seeking bees have genetic brain patterns that set them apart from timid bees. (Chris Gash via NYT) Some honeybees are known to be thrill-seeking adventurers. Known as scouts, they fearlessly leave their hives and search for new sources of food and new hive locations for the rest of the colony. Now, a new study suggests that these scouts have genetic brain patterns that set them apart from other bees. “We found massive differences in brain gene expressions between scouts and nonscouts,” said Gene E Robinson, a geneticist at the University of Illinois, Urbana-Champaign, and an author of the study, which appears in the current issue of the journal Science. The scientists also found that by increasing or inhibiting certain chemicals in the brain, they could encourage scouting behaviour in otherwise timid bees, and suppress it in the thrill seekers.

“By manipulating some neurochemical pathways, we could increase the chances of scouting behaviour,” Robinson said. That behaviour, he added, has analogues in human society. Just as human novelty seekers run the gamut from bold leaders to drug takers to enthusiasts for extreme sports like bungee jumping, the new research indicates that scouting bees also have a range of brain variations. “We find this intriguing parallel, and we see these molecular similarities,” Robinson said. The chemicals that seem to be connected to scouting activity include catecholamine, glutamate and gamma-aminobutyric acid – all chemicals that are also involved in regulating thrill-seeking behaviour in humans and other vertebrates. The researchers think these molecular pathways evolved similarly in bees and humans.

A nose for attacks

A new study details the way the sawfish uses its trademark long, toothy snout to swiftly and fiercely attack prey. The fish is anything but the lazy bottom dweller it was once thought to be, the authors report in the journal Current Biology. “They will swim up and attack with these really fast cuts with their saw,” said Barbara Wueringer, a vertebrate biologist at the University of Western Australia who worked on the research as part of her graduate studies at the University of Queensland. Wueringer’s team found that the snouts of freshwater sawfish are covered with thousands of receptors that allow them to detect the electric fields of other animals and plan an attack. Sawfish are rare, and in Australia they reside in murky waters, so Wueringer and her colleagues used fish collected by a company that sells them to public aquariums.

To simulate a wild setting, they fed the sawfish dead prey with weak electrical fields. Wueringer noted that for ethical reasons, aquariums do not feed their sawfish with live fish, so the electroreceptors may go unused. It may be important to find ways to change that pattern, she said, adding: “Holding animals in captivity over a few generations can cause changes in their behaviour and also their sensory systems. ”

Sindya N Bhanoo
New York Times News Service