Abstract
The entorhinal-hippocampal circuit can encode features of elapsed time, but nearly all previous research focused on neural encoding of “implicit time.” Recent research has revealed encoding of “explicit time” in the medial entorhinal cortex (MEC) as mice are actively engaged in an interval timing task. However, it is unclear whether the MEC is required for temporal perception and/or learning during such explicit timing tasks. We therefore optogenetically inactivated the MEC as mice learned an interval timing “door stop” task that engaged mice in immobile interval timing behavior and locomotion-dependent navigation behavior. We find that the MEC is critically involved in learning of interval timing but not necessary for estimating temporal duration after learning. Together with our previous research, these results suggest that activity of a subcircuit in the MEC that encodes elapsed time during immobility is necessary for learning interval timing behaviors.
| Original language | English (US) |
|---|---|
| Article number | 108163 |
| Journal | Cell reports |
| Volume | 32 |
| Issue number | 12 |
| DOIs | |
| State | Published - Sep 22 2020 |
Funding
We thank C. Woolley for use of the freezing microtome and G. Kozorovitskiy for the use of the slide scanning microscope. This work was supported by The McKnight Foundation (to D.A.D.), a post-doctoral fellowship from The Simons Collaboration on the Global Brain (to J.G.H.), The Chicago Biomedical Consortium with support from the Searle Foundation at The Chicago Community Trust (to D.A.D.), and the NIH ( 2R01MH101297 to D.A.D.).
Keywords
- hippocampus
- interval timing
- learning
- medial entorhinal cortex
- memory
- optogenetic inactivation
- optogenetic stimulation
- virtual reality
ASJC Scopus subject areas
- General Biochemistry, Genetics and Molecular Biology