Brief neuronal afterdischarges in the rat hippocampus lead to transient changes in oscillatory activity and to a very long-lasting decline in BOLD signals without inducing a hypoxic state

The effects of hippocampal neuronal afterdischarges (nAD) on hemodynamic parameters, such as blood-oxygen-level-dependent (BOLD) signals) and local cerebral blood volume (CBV) changes, as well as neuronal activity and metabolic parameters in the dentate gyrus, was investigated in rats by combining i...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Albert Arboit, Shih-Pi Ku, Karla Krautwald, Frank Angenstein
Formato: article
Lenguaje:EN
Publicado: Elsevier 2021
Materias:
Acceso en línea:https://doaj.org/article/696edf603905496ea5960b1cc487c4fd
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
id oai:doaj.org-article:696edf603905496ea5960b1cc487c4fd
record_format dspace
spelling oai:doaj.org-article:696edf603905496ea5960b1cc487c4fd2021-12-04T04:33:18ZBrief neuronal afterdischarges in the rat hippocampus lead to transient changes in oscillatory activity and to a very long-lasting decline in BOLD signals without inducing a hypoxic state1095-957210.1016/j.neuroimage.2021.118769https://doaj.org/article/696edf603905496ea5960b1cc487c4fd2021-12-01T00:00:00Zhttp://www.sciencedirect.com/science/article/pii/S1053811921010417https://doaj.org/toc/1095-9572The effects of hippocampal neuronal afterdischarges (nAD) on hemodynamic parameters, such as blood-oxygen-level-dependent (BOLD) signals) and local cerebral blood volume (CBV) changes, as well as neuronal activity and metabolic parameters in the dentate gyrus, was investigated in rats by combining in vivo electrophysiology with functional magnetic resonance imaging (fMRI) or 1H-nuclear magnetic resonance spectroscopy (1H-NMRS). Brief electrical high-frequency pulse-burst stimulation of the right perforant pathway triggered nAD, a seizure-like activity, in the right dentate gyrus with a high incidence, a phenomenon that in turn caused a sustained decrease in BOLD signals for more than 30 min. The decrease was associated with a reduction in CBV but not with signs of hypoxic metabolism. nAD also triggered transient changes mainly in the low gamma frequency band that recovered within 20 min, so that the longer-lasting altered hemodynamics reflected a switch in blood supply rather than transient changes in ongoing neuronal activity. Even in the presence of reduced baseline BOLD signals, neurovascular coupling mechanisms remained intact, making long-lasting vasospasm unlikely. Subsequently generated nAD did not further alter the baseline BOLD signals. Similarly, nAD did not alter baseline BOLD signals when acetaminophen was previously administered, because acetaminophen alone had already caused a similar decrease in baseline BOLD signals as observed after the first nAD. Thus, at least two different blood supply states exist for the hippocampus, one low and one high, with both states allowing similar neuronal activity. Both acetaminophen and nAD switch from the high to the low blood supply state. As a result, the hemodynamic response function to an identical stimulus differed after nAD or acetaminophen, although the triggered neuronal activity was similar.Albert ArboitShih-Pi KuKarla KrautwaldFrank AngensteinElsevierarticlePostictal stateNegative BOLD1H-NMR spectroscopyGamma oscillationsElectrophysiologyNeurosciences. Biological psychiatry. NeuropsychiatryRC321-571ENNeuroImage, Vol 245, Iss , Pp 118769- (2021)
institution DOAJ
collection DOAJ
language EN
topic Postictal state
Negative BOLD
1H-NMR spectroscopy
Gamma oscillations
Electrophysiology
Neurosciences. Biological psychiatry. Neuropsychiatry
RC321-571
spellingShingle Postictal state
Negative BOLD
1H-NMR spectroscopy
Gamma oscillations
Electrophysiology
Neurosciences. Biological psychiatry. Neuropsychiatry
RC321-571
Albert Arboit
Shih-Pi Ku
Karla Krautwald
Frank Angenstein
Brief neuronal afterdischarges in the rat hippocampus lead to transient changes in oscillatory activity and to a very long-lasting decline in BOLD signals without inducing a hypoxic state
description The effects of hippocampal neuronal afterdischarges (nAD) on hemodynamic parameters, such as blood-oxygen-level-dependent (BOLD) signals) and local cerebral blood volume (CBV) changes, as well as neuronal activity and metabolic parameters in the dentate gyrus, was investigated in rats by combining in vivo electrophysiology with functional magnetic resonance imaging (fMRI) or 1H-nuclear magnetic resonance spectroscopy (1H-NMRS). Brief electrical high-frequency pulse-burst stimulation of the right perforant pathway triggered nAD, a seizure-like activity, in the right dentate gyrus with a high incidence, a phenomenon that in turn caused a sustained decrease in BOLD signals for more than 30 min. The decrease was associated with a reduction in CBV but not with signs of hypoxic metabolism. nAD also triggered transient changes mainly in the low gamma frequency band that recovered within 20 min, so that the longer-lasting altered hemodynamics reflected a switch in blood supply rather than transient changes in ongoing neuronal activity. Even in the presence of reduced baseline BOLD signals, neurovascular coupling mechanisms remained intact, making long-lasting vasospasm unlikely. Subsequently generated nAD did not further alter the baseline BOLD signals. Similarly, nAD did not alter baseline BOLD signals when acetaminophen was previously administered, because acetaminophen alone had already caused a similar decrease in baseline BOLD signals as observed after the first nAD. Thus, at least two different blood supply states exist for the hippocampus, one low and one high, with both states allowing similar neuronal activity. Both acetaminophen and nAD switch from the high to the low blood supply state. As a result, the hemodynamic response function to an identical stimulus differed after nAD or acetaminophen, although the triggered neuronal activity was similar.
format article
author Albert Arboit
Shih-Pi Ku
Karla Krautwald
Frank Angenstein
author_facet Albert Arboit
Shih-Pi Ku
Karla Krautwald
Frank Angenstein
author_sort Albert Arboit
title Brief neuronal afterdischarges in the rat hippocampus lead to transient changes in oscillatory activity and to a very long-lasting decline in BOLD signals without inducing a hypoxic state
title_short Brief neuronal afterdischarges in the rat hippocampus lead to transient changes in oscillatory activity and to a very long-lasting decline in BOLD signals without inducing a hypoxic state
title_full Brief neuronal afterdischarges in the rat hippocampus lead to transient changes in oscillatory activity and to a very long-lasting decline in BOLD signals without inducing a hypoxic state
title_fullStr Brief neuronal afterdischarges in the rat hippocampus lead to transient changes in oscillatory activity and to a very long-lasting decline in BOLD signals without inducing a hypoxic state
title_full_unstemmed Brief neuronal afterdischarges in the rat hippocampus lead to transient changes in oscillatory activity and to a very long-lasting decline in BOLD signals without inducing a hypoxic state
title_sort brief neuronal afterdischarges in the rat hippocampus lead to transient changes in oscillatory activity and to a very long-lasting decline in bold signals without inducing a hypoxic state
publisher Elsevier
publishDate 2021
url https://doaj.org/article/696edf603905496ea5960b1cc487c4fd
work_keys_str_mv AT albertarboit briefneuronalafterdischargesintherathippocampusleadtotransientchangesinoscillatoryactivityandtoaverylonglastingdeclineinboldsignalswithoutinducingahypoxicstate
AT shihpiku briefneuronalafterdischargesintherathippocampusleadtotransientchangesinoscillatoryactivityandtoaverylonglastingdeclineinboldsignalswithoutinducingahypoxicstate
AT karlakrautwald briefneuronalafterdischargesintherathippocampusleadtotransientchangesinoscillatoryactivityandtoaverylonglastingdeclineinboldsignalswithoutinducingahypoxicstate
AT frankangenstein briefneuronalafterdischargesintherathippocampusleadtotransientchangesinoscillatoryactivityandtoaverylonglastingdeclineinboldsignalswithoutinducingahypoxicstate
_version_ 1718372971874091008