Hypothalamic supramammillary nucleus regulates hippocampal CA1 interneurons
The hypothalamic supramammillary nucleus (SuM) projects to CA1, the main hippocampal output region, is unclear.
The researchers report a glutamatergic pathway from the hypothalamic supramammillary nucleus (SuM) that selectively excites CA1 interneurons in the stratum radiatum/stratum lacunosum-moleculare (SR/SLM) border and completely avoids CA1 pyramidal neurons and parvalbumin- or somatostatin-expressing cells.
The authors also show that SuM activation drives spikes in most SR/SLM interneurons to suppress CA1 pyramidal neuronal excitability.
This study demonstrates that the SuM can directly regulate CA1, bypassing CA2, CA3, and the dentate gyrus.
https://www.cell.com/cell-reports/fulltext/S2211-1247(24)01249-X
