Theta–gamma coupling increases during the learning of item–context associations

Phase-amplitude cross-frequency coupling (CFC) between theta (4-12 Hz) and gamma (30-100 Hz) oscillations occurs frequently in the hippocampus. However, it still remains unclear whether theta-gamma coupling has any functional significance. To address this issue, we studied CFC in local field potential oscillations recorded from the CA3 region of the dorsal hippocampus of rats as they learned to associate items with their spatial context. During the course of learning, the amplitude of the low gamma subband (30-60 Hz) became more strongly modulated by theta phase in CA3, and higher levels of theta-gamma modulation were maintained throughout overtraining sessions. Furthermore, the strength of theta-gamma…

• NS
  National Science Foundation

  Award: MH71702
• BW
  Burroughs Wellcome Fund
• NI
  National Institutes of Health
• NI
  National Institute of Mental Health

  Awards: MH71702, MH051570