title: Unique processing during a period of high excitation/inhibition balance in adult-born neurons.
abstract: The adult dentate gyrus generates new granule cells (GCs) that develop over several weeks and integrate into the preexisting network. Although adult hippocampal neurogenesis has been implicated in learning and memory, the specific role of new GCs remains unclear. We examined whether immature adult-born neurons contribute to information encoding. By combining calcium imaging and electrophysiology in acute slices, we found that weak afferent activity recruits few mature GCs while activating a substantial proportion of the immature neurons. These different activation thresholds are dictated by an enhanced excitation/inhibition balance transiently expressed in immature GCs. Immature GCs exhibit low input specificity that switches with time toward a highly specific responsiveness. Therefore, activity patterns entering the dentate gyrus can undergo differential decoding by a heterogeneous population of GCs originated at different times.
authors.affiliation: Laboratorio de Plasticidad Neuronal, Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Avenida Patricias Argentinas 435, 1405 Buenos Aires, Argentina.
authors.forename: Antonia
authors.initials: A
authors.lastname: Marín-Burgin
authors.forename: Lucas A
authors.initials: LA
authors.lastname: Mongiat
authors.forename: M Belén
authors.initials: MB
authors.lastname: Pardi
authors.forename: Alejandro F
authors.initials: AF
authors.lastname: Schinder
mesh_terms: D000818:Animals; D018891:Dentate Gyrus / Q000166:cytology* / Q000502:physiology*; D004558:Electric Stimulation; D018728:Entorhinal Cortex / Q000166:cytology / Q000502:physiology; D019706:Excitatory Postsynaptic Potentials; D005260:Female; D059330:GABAergic Neurons / Q000502:physiology; D018698:Glutamic Acid / Q000378:metabolism; D053444:Inhibitory Postsynaptic Potentials; D051379:Mice; D008810:Mice, Inbred C57BL; D009433:Neural Inhibition; D055495:Neurogenesis; D009473:Neuronal Plasticity; D009474:Neurons / Q000166:cytology / Q000502:physiology*; D018408:Patch-Clamp Techniques; D019580:Perforant Pathway; D013569:Synapses / Q000502:physiology; D055366:Synaptic Potentials
chemical_list: D018698:Glutamic Acid