Summary: Researchers found that the same hippocampal neurons bats use for mapping physical space also encode social information when bats move together. Using wireless neural recordings and imaging, the team monitored groups of Egyptian fruit bats flying and interacting in a large flight room to reveal how place cells represent both location and social context.
Individual “place” neurons in the hippocampus signaled not only where a bat was in the room but also whether other bats were present at specific locations and which individual was there. These results illuminate how the hippocampus integrates spatial and social information and may help explain why hippocampal damage in humans affects both spatial memory and social aspects of episodic memory in conditions like Alzheimer’s disease.
Key Facts:
- Scientists used wireless electrophysiology and calcium imaging to record hippocampal activity from Egyptian fruit bats flying and socializing in a naturalistic group setting.
- Hippocampal place neurons encoded more than physical location: they reflected the presence or absence of other bats at landing sites and could signal the identity of specific conspecifics.
- The findings highlight the importance of studying natural behavior in neuroscience and suggest the hippocampus contributes to both spatial mapping and social navigation.
Source: UC Berkeley
The same neurons that guide bats through space also appear to help them navigate social environments, according to a new study published in Nature.
Many mammals, including humans and bats, rely on the hippocampus to create a mental map of their surroundings. Classic experiments show that individual hippocampal neurons, often called place cells, become active when an animal is in particular locations. In this study, researchers at the University of California, Berkeley extended that perspective by observing freely behaving groups of Egyptian fruit bats.
The team equipped bats with wireless recording and imaging devices and tracked their flights and landings inside a spacious flight room. Bats often clustered in tight social groups and repeatedly visited a small set of preferred resting spots. Tracking data revealed that their flight paths and landing choices were far from random: individuals showed consistent preferences for particular locations and for specific social partners.
Analyzing hippocampal activity, researchers discovered that place neurons carried additional information in social settings. When a bat approached a landing site, the neurons’ firing patterns indicated whether another bat was already present. When another individual occupied the site, the same neurons often reflected the identity of that conspecific.
“This is one of the first demonstrations of identity representation outside of primates,” said Michael Yartsev, associate professor of bioengineering and neuroscience at UC Berkeley and senior author on the study. “The hippocampus still functions as a GPS, but it is also tuned to the social dynamics of the environment.”
First author Angelo Forli, a postdoctoral fellow in the NeuroBat lab, noted that team members were initially concerned that free-moving groups would behave too randomly for clear neural-behavioral correlations to emerge. Instead, the bats established precise and stable group patterns—habitual routes, repeat landing sites and consistent social preferences—making it possible to link neural signals with specific collective behaviors.
These regular patterns allowed the researchers to isolate neural responses tied to both spatial trajectories and the social context at target locations. By recording activity from a modest number of hippocampal neurons, the team could predict whether a bat was heading to an empty spot or toward another individual and, in many cases, identify which individual that was.
Yartsev’s lab has previously used wireless neural tools and flight tracking to reveal coordinated neural activity during social interactions, frontal-cortex signals distinguishing self and other during vocal exchanges, hippocampal mapping of flight trajectories, and mechanisms of stable spatial memory. This study unites those lines of work by showing that hippocampal representations simultaneously capture spatial structure and social information.
The findings offer a potential explanation for why hippocampal damage in humans produces deficits in both spatial navigation and social components of episodic memory. “Our memories combine the places we are with the people and events that occur there,” Yartsev said. “Observing social representations at the level of individual neurons helps bridge spatial mapping and social memory.”
Beyond the specific results, the study underscores the value of studying brains under natural, socially rich conditions rather than in simplified laboratory setups. “For decades, place cells were studied almost exclusively in single animals moving through empty arenas,” Yartsev noted. “Studying animals in more natural social environments reveals additional dimensions of hippocampal function.”
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), the Air Force Office of Scientific Research (FA9550-17-1-0412), the Packard Fellowship (2017-66825), the National Institute of Neurological Disorders and Stroke (R01NS118422-01), the Vallee Foundation (VS-2020-34), the Office of Naval Research (N00014-21-1-2063), the Searle Scholars Program (SSP-2016-1412), the Human Frontiers Fellowship (LT000302/2020) and the European Molecular Biology Organization (1022-2019).
About this social behavior research news
Author: Kara Manke
Source: UC Berkeley
Contact: Kara Manke – UC Berkeley
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Hippocampal Representation During Collective Spatial Behavior in Bats” by Michael Yartsev et al. Nature
Abstract
Hippocampal Representation During Collective Spatial Behavior in Bats
Social animals move through environments shaped by the presence, motion and sensory cues of other individuals. Although hippocampal activity is well known to reflect spatial behavior, its role in dynamic group settings common in nature has been less explored.
In groups of freely behaving bats engaged in collective spatial behavior, robust group-level spatial structure emerged: behavior concentrated around specific locations and repeated movement patterns tied to individual social preferences. Wireless electrophysiological recordings from both perched and flying bats showed that many hippocampal neurons are tuned to features of group dynamics, including the presence or absence of a conspecific at landing sites, the identities of individuals at shared locations, and sensory signals broadcast within the group—responses that were not typically driven by inanimate objects.
Wireless calcium imaging revealed that social responses are anatomically distributed and clearly represented at the population level. Together, these findings indicate that hippocampal activity contains a rich representation of naturally emerging spatial and social behaviors in groups, which could support the complex coordination required for collective behavior.