Abstract
Episodic memories formed in early childhood rapidly decay, but their latent traces remain stored long term. These memories require the dorsal hippocampus (dHPC) and seem to undergo a developmental critical period. It remains to be determined whether the maturation of parvalbumin interneurons (PVIs), a major mechanism of critical periods, contributes to memory development. Here, we show that episodic infantile learning significantly increases the levels of parvalbumin in the dHPC 48 h after training. Chemogenetic inhibition of PVIs before learning indicated that these neurons are required for infantile memory formation. A bilateral dHPC injection of the γ-aminobutyric acid type A receptor agonist diazepam after training elicited long-term memory expression in infant rats, although direct PVI chemogenetic activation had no effect. Finally, PVI activity was required for brain-derived neurotrophic factor (BDNF)-dependent maturation of memory competence, i.e., adult-like long-term memory expression. Thus, dHPC PVIs are critical for the formation of infantile memories and for memory development.
Original language | English (US) |
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Article number | 111643 |
Journal | Cell Reports |
Volume | 41 |
Issue number | 7 |
DOIs | |
State | Published - Nov 15 2022 |
Keywords
- BDNF
- CP: Neuroscience
- critical period
- hippocampus
- infant
- infantile amnesia
- interneurons
- memory
- parvalbumin
- rat
ASJC Scopus subject areas
- General Biochemistry, Genetics and Molecular Biology