Theta power and theta‐gamma coupling support long‐term spatial memory retrieval

Abstract

Hippocampal theta oscillations have been implicated in spatial memory function in both rodents and humans. What is less clear is how hippocampal theta interacts with higher frequency oscillations to support long‐term memory. Here we asked 10 presurgical epilepsy patients undergoing intracranial EEG recording to perform a long‐term spatial memory task in desktop virtual reality and found that increased theta power in two discrete bands (“low” 2‐5 Hz and “high” 6‐11 Hz) during cued retrieval was associated with improved task performance. Similarly, increased coupling between “low” theta phase and gamma amplitude during the same period was associated with improved task performance. Finally, low and high gamma amplitude appeared to peak at different phases of the theta cycle; providing a novel connection between human hippocampal function and rodent data. These results help to elucidate the role of theta oscillations and theta‐gamma phase‐amplitude coupling in human long‐term memory.

The Medial Septum as a Potential Target for Treating Brain Disorders Associated With Oscillopathies

“…The slower oscillations are more prevalent in the anterior HPC (equivalent to the ventral HPC in rodents) without any relationship to movement speed. Furthermore, another study proved that theta–gamma phase amplitude coupling (PAC) also exists in humans, and this supports memory ( Vivekananda et al, 2021 ). These studies indicate that the physiological roles of theta oscillations are similar in rodents and humans.…”

Connectivity in Large-Scale Resting State Brain Networks is Related to Motor Learning: a High-Density EEG Study

“…Specifically, higher baseline delta and theta connectivity was related to poorer initial motor learning and higher baseline beta connectivity predicted lower overnight consolidation. Research into the functional significance of theta band oscillations has highlighted an integral role of this rhythm in memory formation [62,63] and retrieval [64,65] processes, which appear to be supported by gamma-theta cross frequency coupling [66,67]. In the motor domain, theta power over the right parietal region has been positively associated with the degree of learning and retention on a visuomotor task and gamma-theta phase coherence has been shown to be critical for movement planning [25].…”

Effect of θ–γ neural oscillation stimulation in hippocampal CA3 area on spatial cognition ability in rats

“…Compared with the general avoidance response rats, the days to reach the standard, the training number, the correct response time and the error reaction number in simulated stimulus avoidance response rats were significantly reduced, but the correct response rate was significantly increased (all P<0.01); the θ-γ neural oscillations PAC in the hippocampal CA3 region in the simulated stimulus avoidance response rats (3)(4)(5)(38)(39)(40)(41)(42)(44)(45)(46)(47)(48)(5)(6)(7)(44)(45)(46)(47)(48)(54)(55)(56)(57)(58) were significantly higher than that in the general avoidance response rats (all P<0.05). Meanwhile, the protein expressions of NR2B and PSD-95 in hippocampal tissues were significantly increased (both P<0.05) in simulated stimulus avoidance response rats.…”