Activation of the medial entorhinal cortex drives memory-guided navigation behavior

Area of Science:

• Neuroscience
• Cognitive Science
• Behavioral Biology

Background:

• The medial entorhinal cortex (MEC) is vital for spatial memory and navigation.
• Its role in driving memory-guided navigation remains unclear, limiting causal inference.

Purpose of the Study:

• To determine if medial entorhinal cortex (MEC) activation is sufficient to guide memory-based navigation.
• To investigate the causal relationship between MEC activity and spatial memory.

Main Methods:

• Mice navigated a virtual track for reward, with their MEC activity optogenetically manipulated.
• Spatial activity patterns in the MEC were analyzed during learning and navigation.
• The impact of targeted MEC stimulation on reward-predictive behaviors was assessed.

Main Results:

• Spatial activity in the MEC's pre-reward region showed high consistency and correlated with behavioral improvements.
• Widespread MEC neuron activation, not specific cell types, supported reward prediction.
• Spatially consistent MEC activation at non-reward sites biased navigation and induced anticipatory behaviors, indicating memory formation.
• Consistent MEC activation enhanced reward prediction in animals with poor track learning.

Conclusions:

• Spatially consistent MEC activation is sufficient to drive memory-guided reward prediction.
• This study provides causal evidence for the MEC's role in spatial memory and navigation.