Memoirs of a Bat

The smallest GPS devices in the world will be used to track the movement of bats

Dr. Nahum Ulanovsky.

Unforgettable, that's what you are
Unforgettable though near or far
Like a song of love that clings to me
How the thought of you does things to me

"Unforgettable"
Lyrics and music: Irving Gordon
Performed by: Nat "King" Cole

Bats got a bad name through no fault of their own. Perhaps because these flying mammals are active at night, they have the image of a whimsical animal that inspires fear and inspires legends about vampires and witches. On the other hand, in Chinese mythology, the bat actually brings good luck. On the other hand, at the Weizmann Institute of Science, the bats will soon help us learn about the secrets of human memory.

Bats are chatty and "auditory" animals, constantly communicating with their own species through high-pitched shrieks and signals that sound like "clicks", some of which are beyond the range of human hearing. But they also have something to be proud of in the field of navigation and memory. Thus, the fruit bats, the most common species in the country, fly dozens of kilometers every day and know how to return to the exact same cave, with the tiny opening, from which they set out on their nightly journey.

Dr. Nachum Ulanovsky, who recently joined the Weizmann Institute of Science's Department of Neurobiology as a senior researcher, says that the bat is a particularly suitable research model for the study of memory. Not only thanks to its impressive spatial memory, but also thanks to its developed senses and unique behaviors. Dr. Ulanovsky: "Many studies In the field of memory, it is done in rats and mice, and it is worth checking not only if what we already know in this field is also valid in other mammals, unless there are features of memory systems that are not developed in certain mammals but have developed in others. This way we can identify characteristics common to all mammals, and thus learn about ourselves as well."

Dr. Ulanovsky is mainly interested in the connection between memory and electrical activity in the area of ​​the brain called the hippocampus. It is a cluster of nerve cells located in the front part of the brain, responsible for navigation in space and the type of memory called "experiential memory", or "episodic memory". In contrast to motor memory (e.g. , a skill like riding a bicycle), or factual (eg, the name of the Queen of England), episodic memory is everyday memory that allows us to remember what happened, where and when
For example, thanks to it we remember what we did yesterday or who we met two days ago - events of which the dimension of time is an inseparable part.

The crucial role of the hippocampus in episodic memory is best known from a famous case in which a certain patient underwent, in the 50s, an operation to remove the hippocampus to alleviate a severe epilepsy problem.

As a result, he lost the ability to remember new events. However, the existing knowledge about nerve cells or neuronal networks associated with episodic memory is still scarce, and this is exactly what Dr. Ulanovsky aims to find out through his research in bats. He plans to study the activity of the bat's brain during flight or crawling. In the specially built "flight room" in his laboratory The new, the bats will carry on their bodies advanced telemetry equipment that transmits information about the activity of individual neurons or groups of neurons. Another ("ground") system. You will receive and store the information that will be analyzed later.

The Israeli fruit bat is suitable for this task, since its weight is about 150 grams, and it is able to carry equipment weighing 9-8 grams on its body. This is equipment that is a global innovation: the miniature system was developed in the last two years in collaboration between an American company and Dr. Ulanovsky. The scientists will record the information about the activity of the nerve cells using tetrodes, which are microelectrodes with four wires instead of one wire, which allows for a more accurate recording of their activity of single cells Dr. Ulanovsky has already started using these technologies in his post-doctoral research at the University of Maryland, where he arrived. For some important discoveries about the hippocampus of bats, compared to brain activity in this area in rodents and monkeys.

In another experimental room, Ulanovsky will investigate how the brains of bats process sounds. A third experimental room will be dedicated to studying the behavior of bats. In order to disrupt their natural behavior as little as possible, the bats will be housed in the institute in conditions that are as similar as possible to their living conditions in the wild: exposed stones have been installed in the ceiling of the spacious living space built for them, which gives the place the feeling of a cave.

In addition, Dr. Ulanovsky is conducting field research in collaboration with scientists from the Hebrew University. For this research, the smallest GPS device in the world, about four centimeters including the battery, was specially developed. This system will be installed in the bodies of bats, and will allow tracking of their movement in the wild.

These studies, designed to achieve a better understanding of memory, may also contribute to understanding the processes of degenerative diseases such as Alzheimer's disease, as well as severe epilepsy, and diseases related to processes that occur in the hippocampus. In the end, they will contribute, among other things, to understanding the lifestyle of our little neighbor, who flies at night among the trees of the Weizmann Institute and his houses and chatters incessantly, but we simply do not understand what.

personal

Nahum Ulanovsky immigrated to Israel with his parents from Moscow in 1973, when he was a four-month-old baby. The family lived in the city of Rehovot, and Nahum participated in the institute's classes for science-seeking youth. "I feel like I've come home," he says. "In the meantime, new buildings have been erected at the institute and various roads have been paved. Only the swimming pool has remained as it was."

When he enrolled in physics studies at Tel Aviv University at the age of 16, his mother was surprised, who thought he would choose life sciences, since as a child he always loved nature. He graduated with a bachelor's degree at the age of 19, served in the intelligence corps, and during his military service began taking courses in neurobiology. He did his doctorate at the Hebrew University, in the field of neural computing. Dr. Ulanovsky is married, the father of three children, and lives in Rehovot.