biostudies-literatureUnknown29(10)Carretero-Guillen AThe hippocampus is crucial for acquiring and retrieving episodic and contextual memories. In previous studies, the inactivation of dentate gyrus (DG) neurons by chemogenetic- and optogenetic-mediated hyperpolarization led to opposing conclusions about DG's role in memory retrieval. One study used Designer Receptors Exclusively Activated by Designer Drugs (DREADD)-mediated clozapine N-oxide (CNO)-induced hyperpolarization and reported that the previously formed memory was erased, thus concluding that denate gyrus is needed for memory maintenance. The other study used optogenetic with halorhodopsin induced hyperpolarization and reported and dentate gyrus is needed for memory retrieval. We hypothesized that this apparent discrepancy could be due to the length of hyperpolarization in previous Molecular psychiatry2939-2950https://www.ebi.ac.uk/biostudies/studies/S-EPMC11449802biostudies-literatureDentate gyrus is needed for memory retrieval.PMC11449802Larkum MEGomez-Climent MAVlachos AGruart AHasan MTSprengel RCarretero-Guillen ABertocchi IDogbevia GKTrevino MDelgado-Garcia JMfalseDentate gyrus is needed for memory retrieval.The hippocampus is crucial for acquiring and retrieving episodic and contextual memories. In previous studies, the inactivation of dentate gyrus (DG) neurons by chemogenetic- and optogenetic-mediated hyperpolarization led to opposing conclusions about DG's role in memory retrieval. One study used Designer Receptors Exclusively Activated by Designer Drugs (DREADD)-mediated clozapine N-oxide (CNO)-induced hyperpolarization and reported that the previously formed memory was erased, thus concluding that denate gyrus is needed for memory maintenance. The other study used optogenetic with halorhodopsin induced hyperpolarization and reported and dentate gyrus is needed for memory retrieval. We hypothesized that this apparent discrepancy could be due to the length of hyperpolarization in previous 2024-01-01T00:00:00Z2024 Oct2025-04-22T21:43:18.388Z2025-04-06T03:49:06.781ZS-EPMC114498023860958510.1038/s41380-024-02546-0