Hippocampal hub neurons maintain distinct connectivity throughout their lifetime

Marco Bocchio (1) , Claire Gouny (1) , David Angulo-Garcia (1) , Tom Toulat (1) , Thomas Tressard (1) , Eleonora Quiroli (1) , Agnès Baude (1) , Rosa Cossart (1)

1 INMED - INSERM U1249 - Institut de Neurobiologie de la Méditerranée [Aix-Marseille Université]

The temporal embryonic origins of cortical GABA neurons are critical for their specialization. In the neonatal hippocampus, GABA cells born the earliest (ebGABAs) operate as 'hubs' by orchestrating population synchrony. However, their adult fate remains largely unknown. To fill this gap, we have examined CA1 ebGABAs using a combination of electrophysiology, neurochemical analysis, optogenetic connectivity mapping as well as ex vivo and in vivo calcium imaging. We show that CA1 ebGABAs not only operate as hubs during development, but also maintain distinct morpho-physiological and connectivity profiles, including a bias for long-range targets and local excitatory inputs. In vivo, ebGABAs are activated during loco-motion, correlate with CA1 cell assemblies and display high functional connectivity. Hence, ebGABAs are specified from birth to ensure unique functions throughout their lifetime. In the adult brain, this may take the form of a long-range hub role through the coordination of cell assemblies across distant regions.

Keywords: Cellular neuroscience; Development of the nervous system; Neural circuits; Neuronal physiology

Domains: Life Sciences [q-bio]; Neurons and Cognition [q-bio.NC]

Marco Bocchio, Claire Gouny, David Angulo-Garcia, Tom Toulat, Thomas Tressard, et al.. Hippocampal hub neurons maintain distinct connectivity throughout their lifetime. Nature Communications, 2020, 11 (1), ⟨10.1038/s41467-020-18432-6⟩. ⟨hal-02948275⟩