# Mesh electronics for understanding space encoding in the amphibian brain

> **NIH NIH R34** · STANFORD UNIVERSITY · 2022 · $652,647

## Abstract

PROJECT SUMMARY/ABSTRACT
Many animals rely on spatial cognition for daily survival in order to recognize familiar places and process movements
through or between locations. A variety of space-encoding cells in the hippocampus are important for spatial behaviors
in mammals. However, neural encoding of space remains uncharacterized in other vertebrate taxa, including
amphibians, whose simpler brain structure suggests alternative mechanisms of encoding space. The severe gap in our
understanding of how the simple amphibian brain functions stems, in part, from difficulty in recording neural activity.
The amphibian brain exhibits a greater degree of movement within the skull than other vertebrates, which could lead
to an instability of electrophysiology recordings in moving animals using conventional implantable neural probes.
Recently our labs have developed 1) a new form of electronics with tissue-like flexibility and stretchability for
chronically stable neural recording with single-neuron resolution, and 2) cane toads as a model to study the neural
basis of amphibian spatial behaviors. We propose to develop stretchable mesh electronic neural probes for in vivo
electrophysiological recording of single neurons in the medial pallium, the proposed homolog of the mammalian
hippocampus, in freely moving toads. We hypothesize that the medial pallium contains neurons that fire with spatial
specificity, similar to place cells or head direction cells in the mammalian hippocampus, but with lower resolution and
high correlation with specific environmental features (e.g., borders). We predict that single-cell activity of some
neurons in the medial pallium, which is measured by mesh electronics in freely moving toads, will be correlated with
spatial position within a behavioral arena, while neurons recorded from another region will not. Prior to recording
from the medial pallium, we will establish mesh recordings in the optic tectum, a region easily accessible on the dorsal
side of the brain which has been a target for previous electrophysiology studies. We will validate the results with
rigorous statistical analyses and comparison of neural recording data with immunohistological imaging of brain slices.
Understanding how amphibians learn and encode spatial information will reveal either alternative mechanisms for
learning and encoding of spatial experiences or which paradigms are ancestral features of vertebrate brain function
and how neurobiological principles of space coding might generalize across vertebrate taxa. Importantly, our approach
will result in the development of chronically stable recording techniques in brains with large movements in the skull.
This advance will be a valuable research tool for expanding the scope and possibility of electrophysiology studies in
other animals. Successful completion of this project will allow us to obtain proof-of-principle data elucidating
fundamental questions relating neuroanatomy to neuronal functions, which is ...

## Key facts

- **NIH application ID:** 10446284
- **Project number:** 1R34NS127103-01
- **Recipient organization:** STANFORD UNIVERSITY
- **Principal Investigator:** Lisa Giocomo
- **Activity code:** R34 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $652,647
- **Award type:** 1
- **Project period:** 2022-04-01 → 2024-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10446284

## Citation

> US National Institutes of Health, RePORTER application 10446284, Mesh electronics for understanding space encoding in the amphibian brain (1R34NS127103-01). Retrieved via AI Analytics 2026-05-28 from https://api.ai-analytics.org/grant/nih/10446284. Licensed CC0.

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