Protocol for assessing the role of hippocampal perineuronal nets in aversive memories

Summary

Perineuronal nets (PNNs) are emerging as critical regulators of memory-related neuronal processes. However, their exact contribution depends on type of memory, consolidation stage, or brain region, and remains to be fully investigated. We describe here a protocol to evaluate the importance of PNNs in the dorsal hippocampus in different stages of aversive memories using a mouse model. The protocol provides detailed instructions for surgical implantation of hippocampal cannulas, drug infusion, contextual fear conditioning procedures, and immunohistochemistry for PNN visualization.

For complete details on the use and execution of this protocol, please refer to Jovasevic et al. (2021).

Graphical abstract

Highlights

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  Surgical procedure for hippocampal cannula implantation

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  Chondroitinase ABC infusions into the dorsal hippocampus

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  Contextual fear conditioning followed by recent and remote memory tests

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  Immunohistochemistry for perineuronal net visualization

Abstract

Perineuronal nets (PNNs) are emerging as critical regulators of memory-related neuronal processes. However, their exact contribution depends on type of memory, consolidation stage, or brain region, and remains to be fully investigated. We describe here a protocol to evaluate the importance of PNNs in the dorsal hippocampus in different stages of aversive memories using a mouse model. The protocol provides detailed instructions for surgical implantation of hippocampal cannulas, drug infusion, contextual fear conditioning procedures, and immunohistochemistry for PNN visualization.