Ketamine alters oscillatory coupling in the hippocampus
Fábio V. Caixeta, Alianda Maira Cornélio, Robson Scheffer-Teixeira, Sidarta Ribeiro, Adriano B. L. Tort
Scientific Reports August 2, 2013 DOI: 10.1038/srep02348 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Experimental animal study Peer reviewed |
|---|---|
| Population | Awake rats |
| Intervention | Ketamine |
| Dose | 25, 50 and 75 mg/kg i.p. |
| Topics | Ketamine Esketamine |
| Keywords | Hippocampal formation Hippocampus Coupling piping Nmda receptor Schizophrenia object-oriented programming |
| Citations | 134 |
| Key findings | Ketamine alters theta-gamma and theta-high-frequency coupling in the rat hippocampus in a dose-dependent manner, with theta-gamma coupling disrupted at the highest dose. |
Abstract
Recent studies show that higher order oscillatory interactions such as cross-frequency coupling are important for brain functions that are impaired in schizophrenia, including perception, attention and memory. Here we investigated the dynamics of oscillatory coupling in the hippocampus of awake rats upon NMDA receptor blockade by ketamine, a pharmacological model of schizophrenia. Ketamine (25, 50 and 75 mg/kg i.p.) increased gamma and high-frequency oscillations (HFO) in all depths of the CA1-dentate axis, while theta power changes depended on anatomical location and were independent of a transient increase of delta oscillations. Phase coherence of gamma and HFO increased across hippocampal layers. Phase-amplitude coupling between theta and fast oscillations was markedly altered in a dose-dependent manner: ketamine increased hippocampal theta-HFO coupling at all doses, while theta-gamma coupling increased at the lowest dose and was disrupted at the highest dose. Our results demonstrate that ketamine alters network interactions that underlie cognitively relevant theta-gamma coupling.