| Autor: |
Rojas-Líbano D; Laboratorio de Neurociencia Cognitiva y Social, Facultad de Psicología, Universidad Diego Portales , Santiago , Chile., Wimmer Del Solar J; Unidad de Investigación y Desarrollo, Hospital El Carmen de Maipú , Santiago , Chile.; Programa de Neurología, Facultad de Ciencias Médicas, Universidad de Santiago de Chile , Santiago , Chile., Aguilar-Rivera M; Department of Bioengineering, University of California, San Diego, La Jolla, California., Montefusco-Siegmund R; Escuela de Kinesiología, Facultad de Medicina, Universidad Austral de Chile , Valdivia , Chile.; Department of Neuroscience and Biomedical Neuroscience Institute, Universidad de Chile , Santiago , Chile., Maldonado PE; Department of Neuroscience and Biomedical Neuroscience Institute, Universidad de Chile , Santiago , Chile. |
| Abstrakt: |
An important unresolved question about neural processing is the mechanism by which distant brain areas coordinate their activities and relate their local processing to global neural events. A potential candidate for the local-global integration are slow rhythms such as respiration. In this study, we asked if there are modulations of local cortical processing that are phase-locked to (peripheral) sensory-motor exploratory rhythms. We studied rats on an elevated platform where they would spontaneously display exploratory and rest behaviors. Concurrent with behavior, we monitored whisking through electromyography and the respiratory rhythm from the olfactory bulb (OB) local field potential (LFP). We also recorded LFPs from dorsal hippocampus, primary motor cortex, primary somatosensory cortex, and primary visual cortex. We defined exploration as simultaneous whisking and sniffing above 5 Hz and found that this activity peaked at ~8 Hz. We considered rest as the absence of whisking and sniffing, and in this case, respiration occurred at ~3 Hz. We found a consistent shift across all areas toward these rhythm peaks accompanying behavioral changes. We also found, across areas, that LFP gamma (70-100 Hz) amplitude could phase-lock to the animal's OB respiratory rhythm, a finding indicative of respiration-locked changes in local processing. In a subset of animals, we also recorded the hippocampal theta activity and found that occurred at frequencies overlapped with respiration but was not spectrally coherent with it, suggesting a different oscillator. Our results are consistent with the notion of respiration as a binder or integrator of activity between brain regions. |
