6533b7defe1ef96bd1275f1c
RESEARCH PRODUCT
Nucleus incertus contribution to hippocampal theta rhythm generation.
Amparo Ruiz-tornerAngel NuñezVicent TeruelAna Cervera-ferriFrancisco E. Olucha-bordonausubject
MaleHippocampusStimulationHippocampal formationDiagonal Band of BrocaHippocampuschemistry.chemical_compoundRhythmMesencephalonNeural PathwaysmedicineAnimalsRats WistarTheta RhythmBrain MappingGeneral NeuroscienceNucleus IncertusDiagonal band of BrocaElectric StimulationRatsmedicine.anatomical_structurenervous systemMuscimolchemistryFemaleSeptum of BrainNeuroscienceNucleusMicroelectrodesdescription
The hippocampal theta rhythm is generated by the pacemaker activity of the medial septum-diagonal band of Broca (MS/DBB) neurons. These nuclei are influenced by brainstem structures that modulate the theta rhythm. The aim of the present work is to determine whether the nucleus incertus (NI), which has important anatomical connections with the MS/DBB, contributes to the hippocampal theta rhythm generation in rats. Hippocampal field activity was recorded in urethane-anaesthetized rats. Electrical stimulation of the NI not only evoked theta rhythm in the hippocampus, but also decreased the amplitude of delta waves. Unit recordings in the NI revealed either a non-rhythm discharge pattern in most neurons (76%), or a rhythm activity at 13-25 Hz in the remaining neurons. The firing rate of these neurons increased during the presence of theta rhythm evoked by either sensory or reticularis pontis oralis nucleus (RPO) stimulation. Electrolytic lesions of NI, or the microinjection of the gamma-aminobutyric acid (GABA)A agonist muscimol, abolished the theta rhythm evoked by RPO stimulation. Consequently, the NI may be a relay station between brainstem structures and the MS/DBB in the control of the hippocampal theta rhythm generation.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2006-05-01 | The European journal of neuroscience |