The right hippocampus leads the bilateral integration of gamma-parsed lateralized information
Abstract
It is unclear whether the two hippocampal lobes convey similar or different activities and how they cooperate. Spatial discrimination of electric fields in anesthetized rats allowed us to compare the pathway-specific field potentials corresponding to the gamma-paced CA3 output (CA1 Schaffer potentials) and CA3 somatic inhibition within and between sides. Bilateral excitatory Schaffer gamma waves are generally larger and lead from the right hemisphere with only moderate covariation of amplitude, and drive CA1 pyramidal units more strongly than unilateral waves. CA3 waves lock to the ipsilateral Schaffer potentials, although bilateral coherence was weak. Notably, Schaffer activity may run laterally, as seen after the disruption of the connecting pathways. Thus, asymmetric operations promote the entrainment of CA3-autonomous gamma oscillators bilaterally, synchronizing lateralized gamma strings to converge optimally on CA1 targets. The findings support the view that interhippocampal connections integrate different aspects of information that flow through the left and right lobes.
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Author details
Funding
Ministerio de Economía y Competitividad (BFU2013-41533R)
- Nuria Benito
- Gonzalo Martín-Vázquez
- Julia Makarova
- Oscar Herreras
Russian Science Foundation (15-12-10018)
- Valeri A Makarov
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: The experiments were performed in accordance with European Union guidelines (2010/63/CE) and Spanish regulations (BOE 67/8509-12, 1988) regarding the use of laboratory animals. All of the animals were handled according to approved institutional Bioethics and Biosecurity Committee of the CSIC (ref:15/10/2014). The Ethics Committee for Animal Research at the Cajal Institute approved all the experimental protocols (Ref. CEEA-IC2011/011/CEI3/20131213). All surgery was performed under urethane anesthesia, and every effort was made to minimize suffering.
Copyright
© 2016, Benito et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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