Prefrontal Single-Neuron Responses after Changes in Task Contingencies during Trace Eyeblink Conditioning in Rabbits

Area of Science:

• Neuroscience
• Behavioral Neuroscience
• Cognitive Neuroscience

Background:

• The medial prefrontal cortex (mPFC) is implicated in flexible behavioral responses.
• In trace eyeblink conditioning, the mPFC may bridge the temporal gap between stimuli via persistent neural input.
• The role of persistent mPFC activity in adapting learned behaviors to changing task contingencies remains unclear.

Purpose of the Study:

• To investigate whether persistent neural responses in the mPFC are associated with flexible behavioral expression during modified trace eyeblink conditioning tasks.
• To determine if mPFC activity mediates changes in learned responses or generalizes to new stimuli.

Main Methods:

• Single-unit activity was recorded from the mPFC of rabbits.
• Rabbits underwent extinction and reacquisition of trace eyeblink conditioning.
• Neural activity was also recorded during training with a different conditional stimulus.

Main Results:

• Persistent mPFC responses remained stable during extinction and reacquisition of the original conditioning.
• During training with a new stimulus, generalization of persistent mPFC responses correlated with high performance (>50% response rate).
• A decrease in persistent mPFC responses to baseline levels was associated with poor performance (<50% response rate).

Conclusions:

• Persistent mPFC responses do not appear to directly mediate flexible adjustments to previously learned behaviors in trace eyeblink conditioning.
• These persistent mPFC responses may play a role in the generalization of learned associations to novel stimuli when task conditions change.