Lateral entorhinal cortex subpopulations represent experiential epochs surrounding reward

Area of Science:

• Neuroscience
• Cognitive Science
• Memory Research

Background:

• Goal-directed navigation relies on integrating 'what' (experiential) and 'where' (spatial) information for behavior and memory.
• The hippocampus is known to integrate spatial information from the medial entorhinal cortex, but the source of 'what' information remains unclear.

Purpose of the Study:

• To investigate the role of the lateral entorhinal cortex (LEC) in representing experiential information during reward-based navigation.
• To identify neural populations in the LEC that encode specific behavioral epochs related to reward.

Main Methods:

• Utilized mouse models performing reward-based navigation tasks.
• Recorded neural activity in the lateral entorhinal cortex (LEC) to identify neuronal representations of different behavioral phases.
• Employed optogenetic inhibition of the LEC to assess its causal role in learning reward locations.

Main Results:

• Discovered distinct neuronal populations in the LEC that specifically signal goal approach, goal departure, and reward consumption.
• Demonstrated that these neuronal populations dynamically shift their representations when the reward location is altered.
• Showed that inhibiting the LEC impairs the ability to learn new reward locations.

Conclusions:

• The lateral entorhinal cortex (LEC) contains a stable neural code for experiential epochs surrounding reward consumption.
• The LEC provides essential reward-centric information that complements spatial information from the medial entorhinal cortex.
• This study highlights the LEC's critical role in integrating experience and spatial context for navigation and memory formation.