Abstract
The hippocampal dentate gyrus is often viewed as a segregator of upstream information. Physiological support for such function has been hampered by a lack of well-defined characteristics that can identify granule cells and mossy cells. We developed an electrophysiology-based classification of dentate granule cells and mossy cells in mice that we validated by optogenetic tagging of mossy cells. Granule cells exhibited sparse firing, had a single place field, and showed only modest changes when the mouse was tested in different mazes in the same room. In contrast, mossy cells were more active, had multiple place fields and showed stronger remapping of place fields under the same conditions. Although the granule cell-mossy cell synapse was strong and facilitating, mossy cells rarely “inherited” place fields from single granule cells. Our findings suggest that the granule cells and mossy cells could be modulated separately and their joint action may be critical for pattern separation.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 691-704.e5 |
| Journal | Neuron |
| Volume | 93 |
| Issue number | 3 |
| DOIs | |
| State | Published - Feb 8 2017 |
Funding
We thank Lisa Roux and Eran Stark for technical support and extensive discussion. We also thank Nathan Danielson, Antonio Fernández-Ruiz, Jennifer Gelinas, Dion Khodagholy, James Knierim, Attila Losonczy, Sam Mckenzie, and Ivan Soltesz for insightful comments on the manuscript; Anna Conti for help maintaining transgenic animals; and Helen Scharfman and Edward Ziff for providing DRD2-Cre mice. This work was supported by the Nakajima Foundation, NIHMH54671, MH107396, NS 090583, NSF PIRE grant, and the Simons Foundation.
Keywords
- Dentate gyrus
- facilitating synapse
- gamma
- granule cell
- monosynaptic connections
- mossy cell
- pattern separation
- place cells
- spatial behavior
- theta
ASJC Scopus subject areas
- General Neuroscience