New Worlds: Bats, belfries and brain function

A Weizmann Institute researcher is using the winged mammals to help reveal the secrets of human memory.

By JUDY SIEGEL-ITZKOVICH
bat 88 (photo credit: )
bat 88
(photo credit: )
For many Westerners, bats conjure up eerie visions of vampires and witches. The Chinese see these flying rodents as symbols of good luck. A Weizmann Institute researcher however, is using bats to help reveal the secrets of human memory. The Rehovot institute's Interface magazine wrote recently about bat researcher Dr. Nachum Ulanovsky, a neurobiologist who studies the most common Israeli bat species - the fruit bat. He says they are an excellent animal model for human memory not only because of their impressive spatial memory but also due to their highly developed senses and unique behaviors. "Most studies of memory-related brain activity have been done with rats and mice," he says. "It's important to perform a 'reality check' to see whether those findings are relevant for other mammals. By comparing different animals, we can find the features that all mammals have in common, and such features can help us understand our own memory." Ulanovsky wants to know how bat brains process and remember sounds over time. Ulanovsky, who was born in Moscow and was brought to Israel by his parents as a four-month-old baby in 1973, recently began working at Weizmann. He is focusing on the hippocampus area in the brain that is responsible for episodic memory and spatial navigation. Unlike motor memory (remembering how to ride a bicycle or swim) or factual memory (recalling dates of historical events), episodic memory involves day-to-day, short-term memories of what we did yesterday or whom we met last week. When the hippocampus was surgically removed from the brain of a patient half a century ago he lost the ability to remember recent events, and its role became clear. But it is still unknown which nerve cells or neuronal networks are involved in episodic memory. Thus Ulanovsky, who studied bats at he University of Maryland for his post-doctoral work, is working to find this out. Bats are being outfitted with sophisticated telemetry equipment transmitting data about the activity of single neurons or networks. These are used as the bats crawl or fly around in Ulanovsky's lab. A US company working with the Rehovot researcher developed the world's first global positioning and telemetry system that weighs only nine grams; as the average fruit bat can carry nine grams of equipment and still fly with ease, it is the perfect bat species for his experiments. To avoid disrupting the bats' natural behavior, Ulanovsky has arranged for the building of a large cave-like room with rough-hewn rocks in the ceiling. His work, which is partially conducted in collaboration with the Hebrew University, promises to reveal new information not only on human memory but also on hippocampal diseases such as epilepsy and Alzheimer's. GOOD NEWS FOR FROGS AND BIOLOGY PUPILS People who were reluctant to study biology because they had to kill and dissect frogs will be happy to hear of V-Frog, the world's first virtual-reality-based frog dissection software designed for biology education. It allows not only observation, but also physically simulated dissection. Tactus Technologies, a spin-off of the University at Buffalo Virtual Reality Laboratory, developed the software and is marketing it. The technology comes just in time, as more than 25 of the US states have laws or ordinances mandating that, if dissection is part of a school's curriculum, pupils must have an alternative. "Other products out there are multimedia, not true virtual reality," explains Dr. Kevin Chugh, the company's president and chief scientist. V-Frog, which operates on a personal computer using a standard mouse, actually simulates nearly unlimited manipulation of specimen tissue. As a result, every dissection is different, reflecting each pupil's individual work. The software is designed for grades seven through 12, plus advanced placement biology students.