Journal Article

DZNE-2020-01080

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Frequency-dependent electrical stimulation of fimbria-fornix preferentially affects the mesolimbic dopamine system or prefrontal cortex

Helbing, C. (First author)DZNE* ; Angenstein, F. (Last author)DZNE*

2020
Elsevier New York, NY [u.a.]

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Please use a persistent id in citations: doi:10.1016/j.brs.2020.02.026

Abstract: BackgroundThe fimbria/fornix fiber system is an essential part of the hippocampal-VTA loop, and therefore activities that are propagated through this fiber system control the activity of the mesolimbic dopamine system.Objectives/hypothesisWe hypothesized that stimulation of the fimbria/fornix with an increasing number of electrical pulses would cause increasing activity of the mesolimbic dopamine system, which coincides with concurrent changes in neuronal activities in target regions of the mesolimbic dopaminergic system.MethodsRight fimbria/fornix fibers were electrically stimulated with different pulse protocols. Stimulus-induced changes in neuronal activities were visualized with BOLD-fMRI, whereas stimulus-induced release of dopamine, as measured for the activity of the mesolimbic dopamine system, was determined in the nucleus accumbens with in vivo fast-scan cyclic voltammetry.ResultsDependent on the protocol, electrical fimbria/fornix stimulation caused BOLD responses in various targets of the mesolimbic dopamine system. Stimulation in the low theta frequency range (5 Hz) triggered significant BOLD responses mainly in the hippocampal formation, infralimbic cortex, and septum. Stimulation in the beta frequency range (20 Hz) caused additional activation in the medial prefrontal cortex (mPFC), nucleus accumbens, striatum, and VTA. Stimulation in the high-gamma frequency range (100 Hz) caused further activation in the hippocampus proper and mPFC. The strong activation in the mPFC during 100 Hz stimulations depended not only on the number of pulses but also on the frequency. Thus, short bursts of 5 or 20 high-frequency pulses caused stronger activation in the mPFC than continuous 5 or 20 Hz pulses. In contrast, high-frequency burst fimbria/fornix stimulation did not further activate the mesolimbic dopamine system when compared to continuous 5 or 20 Hz pulse stimulation.ConclusionsThere exists a frequency-dependent dissociation between BOLD responses and activation of the dopaminergic system. Low frequencies were more efficient to activate the mesolimbic dopamine system, whereas high frequencies were more efficient to trigger BOLD responses in target regions of the mesolimbic dopamine system, particularly the mPFC.

Keyword(s): Animals (MeSH) ; Brain Mapping: methods (MeSH) ; Deep Brain Stimulation: methods (MeSH) ; Dopamine: physiology (MeSH) ; Dopaminergic Neurons: physiology (MeSH) ; Fornix, Brain: diagnostic imaging (MeSH) ; Fornix, Brain: physiology (MeSH) ; Limbic System: diagnostic imaging (MeSH) ; Limbic System: physiology (MeSH) ; Magnetic Resonance Imaging: methods (MeSH) ; Male (MeSH) ; Prefrontal Cortex: diagnostic imaging (MeSH) ; Prefrontal Cortex: physiology (MeSH) ; Rats (MeSH) ; Rats, Wistar (MeSH)

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Contributing Institute(s):

1. Functional Neuroimaging (AG Angenstein)

Research Program(s):

1. 344 - Clinical and Health Care Research (POF3-344) (POF3-344)

Appears in the scientific report 2020

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Database coverage:
; ; ; ; BIOSIS Previews ; Biological Abstracts ; Clarivate Analytics Master Journal List ; Current Contents - Clinical Medicine ; DOAJ Seal ; Essential Science Indicators ; IF >= 5 ; JCR ; SCOPUS ; Web of Science Core Collection

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