Bats navigate social life using the brain’s Global Positioning System (GPS).

summary: Bats use the same neurons for social navigation as they do for spatial navigation. The study involved wireless neural recording and imaging of groups of Egyptian fruit bats flying in a large room.

The bat’s “spatial” neurons in the hippocampus fired not only to signal the location of the animal, but also the identity of the other bats present. This finding could shed light on the role of the hippocampus in the social and spatial aspects of memory loss in diseases such as Alzheimer’s disease.

Key facts:

• The researchers used wireless neurotechnology to track the activity of the hippocampal brain of Egyptian fruit bats flying in a social environment.
• The “spatial” neurons in the bats’ hippocampus were encoding more than just spatial information; They also encoded social information such as the presence and identity of other bats.
• The study proposes a new perspective for neuroscience research, emphasizing the need to focus on natural behavior rather than simplified or artificial conditions.

source: University of California, Berkeley

The same neurons that help bats navigate through space may also help them navigate group social environments, finds a new study published today in the journal nature.

Many mammals – including bats and humans – are thought to navigate with the help of a brain structure called the hippocampus, which encodes a mental “map” of familiar surroundings.

For example, when you walk around your neighborhood or commute to work, individual neurons in the hippocampus “lay” to indicate where you are.

In the new study, researchers at the University of California, Berkeley, used wireless neuroimaging and recording devices to “listen” to the brain activity in the hippocampi of groups of Egyptian fruit bats as they flew freely inside a large flight chamber — often moving between tightly packed social groups — while a technique recorded Track bat movements.

The researchers were surprised to find that in this social situation, the bat’s position neurons encoded much more information than just the animal’s location. When a bat flies toward a landing point, the firing of position neurons also contains information about the presence or absence of another bat at that spot.

When another bat was present, the activity of these neurons indicated the identity of the bat they were flying towards.

“This is one of the first papers to show identity representation in a non-primate brain,” said Michael Yartsev, senior author of the study and associate professor of bioengineering and neuroscience at UC Berkeley.

“Surprisingly, we found it at the center of what was supposed to be the brain’s GPS. We found that it still functions as a GPS, but is also tuned to the social dynamics in the environment.

Although not as visually stunning as a school of fish or a murmur of birds, highly social animals like humans and bats also exhibit forms of collective behavior, said the study’s first author Angelo Forli, a postdoctoral fellow in the Neurobat Laboratory in Yartsev.

“Social animals, like humans, will coordinate in space to achieve different goals,” Forley said. “It may be just visiting others. It may be moving together, as in classic group behaviors or playing a soccer match. Or it may be other forms of cooperation or conflict.”

Given the complexity of the experiment, Forley initially had doubts about whether allowing groups of bats to fly and interact freely would yield results about the neural basis of collective behavior.

He was concerned that bats’ movements and social interactions might be too random to reveal strong relationships between their neural activity and behavior.

So he was pleasantly surprised when the bats spontaneously created a set of specific resting places within the flight chamber and followed very similar paths when traveling between them. The bats also showed strong preferences for flying toward specific “friendly” bats, often landing near or even on top of each other.

“We found that if you put a small group of bats in a room, they will not behave randomly, but will show specific patterns of behavior,” Forley said. “They would spend time with specific individuals and be shown specific, stable places they wanted to go.”

These subtle patterns of behavior allowed Forley to determine not only the neural activity associated with different flight paths, but also how neural activity changed depending on the identity of the bat at the target location and the movements of other bats.

“By recording just a few of those neurons from this brain structure, we could really know what the bats were doing in their social space,” Yartsev said. “We can tell if they are going to an empty place or to a place where there are other individuals, which is really surprising.”

In recent years, Yartsev and his NeuroBat laboratory have used a variety of wireless neural recording devices and flight-tracking techniques to reveal a number of surprising details about the brain, including how bats’ neural activity is synchronized as they socialize; how activity in the frontal cortex helps bats recognize themselves versus others during vocal interactions; how the hippocampus of bats plots not just specific locations but entire flight paths; and even how stable spatial memories might be stored in the brain.

This new study combines the team’s work in navigation and social behavior, showing how these two things are fundamentally intertwined within the brain. The findings also help explain why damage to the hippocampus in humans is linked to social and spatial aspects of memory loss in neurodegenerative diseases such as Alzheimer’s.

“Our episodic memories are a combination of the environment we are in and our experiences within it, including, of course, our social experiences,” Yartsev said.

“Our results are surprising in the sense that no one has observed this association before in groups of animals and at the level of individual neurons. But they are also logical in that they are very consistent with the deficits experienced by people with hippocampal damage.”

Finally, Yartsev said that this study highlights a very important point. While most of the neuroscientific community examines the brain under “simplified” or “artificial” conditions that are often far removed from the natural behavior that the brain has evolved to promote, this work demonstrates the power of a naturalistic approach to neuroscience research.

“For half a century, people have been studying spatial neurons, but 99 percent of that work has been done in single animals moving around in an empty box,” Yartsev said. “Our findings suggest that there is much to be learned when neuroscience research focuses on normal behavior.”

Funding: This research was supported by the New York Stem Cell Foundation (NYSCF-R-NI40), the National Institute of Mental Health (Award 1-R01MH25387-01), and the Air Force Office of Scientific Research (FA9550-17-1-0412). , Packard Fellowship (2017-66825), National Institute of Neurological Disorders and Stroke (R01NS118422-01), Valley Foundation (VS-2020-34), Office of Naval Research (N00014-21-1-2063), Searle Scholars Program (SSP- 2012-1416), Human Frontiers Fellowship (LT000302/2020), and European Molecular Biology Organization (2019-1022).

About Social Behavior Research News

author: Kara Monkey
source: University of California, Berkeley
communication: Kara Mank – University of California, Berkeley
picture: Image credited to Neuroscience News

Original search: Open access.
“Representation of the hippocampus during collective spatial behavior in batsWritten by Michael Yartsev et al. nature

a summary

Representation of the hippocampus during collective spatial behavior in bats

Social animals live and move through spaces shaped by the presence, movement, and sensory signals of many other individuals.

Neural activity in the hippocampus is known to reflect spatial behavior, but it is poorly studied in such dynamic group settings, which are ubiquitous in natural settings.

Here we investigated hippocampal activity in groups of bats engaged in collective spatial behaviour. We found that under spontaneous conditions, a strong spatial structure emerges at the group level where behavior is anchored by specific locations, movement patterns and individual social preferences.

Using wireless electrophysiological recordings from stationary and flying bats, we find that many hippocampal neurons tuned to key features of group dynamics.

This includes the presence or absence of a specific object, but not usually, at landing sites, shared spatial locations, individual identities and sensory cues broadcast in the group setting.

Finally, using wireless calcium imaging, we find that social responses are anatomically distributed and strongly represented at the population level.

Taken together, our findings reveal that hippocampal activity contains a rich representation of naturally emerging spatial behaviors in animal groups that can in turn support the complex feat of collective behavior.