A1 Journal article (refereed)
Phase matters: responding to and learning about peripheral stimuli depends on hippocampal θ phase at stimulus onset (2015)

Nokia, M., Waselius, T., Mikkonen, J., Wikgren, J., & Penttonen, M. (2015). Phase matters: responding to and learning about peripheral stimuli depends on hippocampal θ phase at stimulus onset. Learning and Memory, 22(6), 307-317. https://doi.org/10.1101/lm.038166.115

JYU authors or editors

Publication details

All authors or editors: Nokia, Miriam; Waselius, Tomi; Mikkonen, Jarno; Wikgren, Jan; Penttonen, Markku

Journal or series: Learning and Memory

ISSN: 1072-0502

eISSN: 1549-5485

Publication year: 2015

Volume: 22

Issue number: 6

Pages range: 307-317

Publisher: Cold Spring Harbor Laboratory Press

Publication country: United States

Publication language: English

DOI: https://doi.org/10.1101/lm.038166.115

Publication open access: Openly available

Publication channel open access: Partially open access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/45973

Abstract

Hippocampal θ (3–12 Hz) oscillations are implicated in learning and memory, but their functional role remains unclear. We studied the effect of the phase of local θ oscillation on hippocampal responses to a neutral conditioned stimulus (CS) and subsequent learning of classical trace eyeblink conditioning in adult rabbits. High-amplitude, regular hippocampal θ-band responses (that predict good learning) were elicited by the CS when it was timed to commence at the fissure θ trough (Trough group). Regardless, learning in this group was not enhanced compared with a yoked control group, possibly due to a ceiling effect. However, when the CS was consistently presented to the peak of θ (Peak group), hippocampal θ-band responding was less organized and learning was retarded. In well-trained animals, the hippocampal θ phase at CS onset no longer affected performance of the learned response, suggesting a time-limited role for hippocampal processing in learning. To our knowledge, this is the first study to demonstrate that timing a peripheral stimulus to a specific phase of the hippocampal θ cycle produces robust effects on the synchronization of neural responses and affects learning at the behavioral level. Our results support the notion that the phase of spontaneous hippocampal θ oscillation is a means of regulating the processing of information in the brain to a behaviorally relevant degree.

Keywords: learning

Free keywords: memory; hippocampal

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Ministry reporting: Yes

Reporting Year: 2015

JUFO rating: 2