Enhancing Prefrontal Neuron Activity Enables Associative Learning of Temporally Disparate Events.
The ability to link events that are separated in time is important for extracting meaning from experiences and guiding behavior in the future. This ability likely requires the brain to continue representing events even after they have passed, a process that may involve the prefrontal cortex and takes the form of sustained, event-specific neuron activity. Here, we show that experimentally increasing the activity of excitatory neurons in the medial prefrontal cortex (mPFC) enables rats to associate two stimuli separated by a 750-ms long temporal gap. Learning is accompanied by ramping increases in prefrontal theta and beta rhythms during the interval between stimuli. This ramping activity predicts memory-related behavioral responses on a trial-by-trial basis but is not correlated with the same muscular activity during non-memory conditions. Thus, the enhancement of prefrontal neuron excitability extends the time course of evoked prefrontal network activation and facilitates the formation of associations of temporally disparate, but correlated, events.
Department of Psychology, University of Toronto, Toronto, ON M5S 3G3, Canada.
Julien
J
Volle
Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G3, Canada.
Xiaotian
X
Yu
Department of Psychology, University of Toronto, Toronto, ON M5S 3G3, Canada.
Huaying
H
Sun
Department of Psychology, University of Toronto, Toronto, ON M5S 3G3, Canada.
Stephanie E
SE
Tanninen
Department of Psychology, University of Toronto, Toronto, ON M5S 3G3, Canada.
Nathan
N
Insel
Department of Psychology, University of Toronto, Toronto, ON M5S 3G3, Canada; Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G3, Canada; Neuroscience Program, University of Toronto, Toronto, ON M5S 3G3, Canada. Electronic address: takehara@psych.utoronto.ca.
Kaori
K
Takehara-Nishiuchi
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D001611:Beta Rhythm / Q000502:physiology; D003214:Conditioning, Classical; D000229:Dependovirus / Q000378:metabolism; D005143:Eyelids / Q000502:physiology; D006801:Humans; D007858:Learning; D008297:Male; D008568:Memory; D009068:Movement; D009474:Neurons / Q000502:physiology*; D017397:Prefrontal Cortex / Q000502:physiology*; D017966:Pyramidal Cells / Q000502:physiology; D020318:Rats, Long-Evans; D013826:Theta Rhythm / Q000502:physiology; D013997:Time Factors; D014161:Transduction, Genetic