Related Experiment Video
Updated: May 31, 2026
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Investigating Long-term Synaptic Plasticity in Interlamellar Hippocampus CA1 by Electrophysiological Field Recording
Published on: August 11, 2019
Retrosplenial perineuronal nets support hippocampal-cortical coupling and spatial memory recall.
Phoebe Hawthorn1, Dongsheng Xiao1, Robert K P Sullivan1
1Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia.
Cell Reports
|May 28, 2026
Summary
Perineuronal nets (PNNs) in the retrosplenial cortex (RSC) are crucial for spatial memory. Degrading PNNs disrupts communication between the hippocampus and RSC, impairing memory recall and neural synchrony.
Area of Science:
- Neuroscience
- Cognitive Neuroscience
- Memory Research
Background:
- The retrosplenial cortex (RSC) is vital for spatial memory, integrating hippocampal information with cortical networks.
- Inhibitory parvalbumin interneurons within the RSC are modulated by perineuronal nets (PNNs), which stabilize neural activity and connections.
- The role of PNNs in cortical regions, specifically in interregional communication, is not well understood.
Purpose of the Study:
- To investigate the impact of PNN degradation in the granular RSC (RSCg) on spatial memory recall.
- To analyze the effects of PNN degradation on neuronal activity within the RSCg and dorsal CA1 (dCA1).
- To elucidate the contribution of PNNs to the functional connectivity between the hippocampus and RSC.
Main Methods:
- PNN degradation was induced in the granular RSC (RSCg) of the study subjects.
- Spatial memory recall was assessed following PNN degradation.
- Electrophysiological recordings were performed in the RSCg and dCA1 to measure neuronal activity and oscillatory patterns.
- Cellular activity was quantified using c-Fos expression to identify active neurons and their relation to PNNs.
Main Results:
- PNN degradation in the RSCg led to significant impairments in spatial memory recall.
- An increase in c-Fos+ and c-Fos+PNN+ cells was observed in the RSCg after PNN degradation.
- Electrophysiology revealed disrupted oscillatory activity, including reduced gamma oscillations and theta-gamma coupling in the RSCg, and diminished theta oscillations in the dCA1.
- Interregional gamma coupling decreased, and functional connectivity between dCA1 and RSCg excitatory neurons was impaired.
Conclusions:
- PNNs in the RSC are essential for maintaining stable, coordinated neural dynamics.
- The degradation of PNNs disrupts hippocampal-RSC communication critical for memory retrieval.
- These findings highlight PNNs as key regulators of interregional communication and spatial memory function.
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