Chickadees recall places by simply looking from afar

Zuckerman researchers Mind Brain Behavior Institute of Columbia University discovered that hippocampal cells in black tips are triggered when the bird just looks at a distant place, revealing a unified spatial memory process trained by vision.

Many animals rely on the vision to trigger a reminder to find out where food is hidden or to trace a course towards distant goals. Placing the hippocampe cells form the neuronal base of such a spatial memory, pulling when an animal enters a specific place.

Previous studies in primates have revealed a certain hippocampal activity linked to the place where the eyes were directed, although the recordings generally involved stationary animals.

The free monitoring of eye movements during active behavior poses persistent technical obstacles as current laboratory models, such as rodents, lack precise control of the gaze. Researchers have not already resolved how the coding of the hippocampal place connects to the act of research visually from afar.

In the study, “remote activation of place codes by look in a very visual animal”, published in NatureThe researchers have designed experiments to determine if the hippocamp cells place in the hair in black hair activate during the visual fixing on remote space targets.

Eight black spikes participated in the experiences, which took place in an arena of 61 centimeters containing five identical sites equipped with perches, light clues and motorized feeders.

The researchers have adapted a multi-limited follow-up system that triangues infrared reflective markers on the head of each bird to record the head position during free movement.

A separate double-camera video-culography system estimated the pupillary axis by capturing corneal reflections, allowing the calibration of the orientation of the eyes. The direction of the gaze was determined mainly by the orientation of the head because the chicks have a minimal independent ocular movement.

The birds carried out a discreet visual research task in which a light signal reported the site rewarded after a random delay, and a closed loop version where the signal was only activated when the bird looked at the correct target. Silicon probes located in the anterior hippocampus have recorded a neural activity.

The recordings of 1,929 excitator hippocampal neurons showed that 62% were settled on the location of the bird during navigation and 57% responded to the direction of the gaze during the stationary visual search.

Among the neurons classified as regulated, 75% also showed a significant look agreement (changes in the rate of shooting when the bird fixed on different target sites). The preferred locations for places and glances overlap in 95% of cells with strong selectivity. The contralateral gaze (opposite) explains most of the setting, with neurons pulling when the eye opposed to the recording hemisphere fixed on a target.

Neuronal responses during rapid head movements (called head jerks) displayed a biphasic pattern: an early component appeared before the bird’s gaze reaches the favorite target, and a subsequent component corresponds to a visual input.

The inhibitory interneurons have gathered in two groups with shooting phases at around 180 degrees both, creating an almost oscillation almost linked to head jerks.

The results indicate that hippocampal activity code a combination of prediction and sensory response linked to the place where the bird attracts visual attention. The results suggest that the movements of the jerky head synchronize the neural activity linked to memory several times per second.

The researchers conclude that space coding and the coding of the gaze form a unified process through which the hippocampus represents the relevant locations for the animal at every moment. Such representations allow both the formation of space memories when a bird visits a site and the recall of these memories from afar.

© 2025 Science X Network