Pharmacological modulation of cholinergic brain activity and its reflection in special EEG frequency ranges from various brain areas in the freely moving rat (Tele-Stereo-EEG)

Dimpfel, Wilfried

doi:10.1016/j.euroneuro.2005.03.006

Cited by 64 publications

(53 citation statements)

References 14 publications

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“…However, depending on the challenge more or less regions were involved. This increase of spectral delta power indicates a major involvement of the cholinergic transmitter system during processing of cognitive as well as emotional challenges not only confined to lateral prefrontal brain [2]. The same pattern was seen with respect to theta power, where also only increases were documented during the different challenges.…”

Section: Discussionsupporting

confidence: 56%

“…Direct measurement of electric activity provides much more information by use of frequency analysis obtained by Fast Fourier Transformation (FFT), since single frequencies have been related to neurotransmitter activities. For example, slow delta waves seem to be under the control of acetylcholine [2]. Spectral power of theta waves changes in the presence of norepinephrine alpha2 receptor agonists [3].…”

Section: Introductionmentioning

confidence: 99%

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EnkephaloVision: Anatomical Functionality Indicated by Ultrashort Transient Regional EEG Spectral Power Changes during Cognitive and Emotional Challenges

Dimpfel¹,

Dipah²,

Gericke³

2016

WJNS

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Anatomical functionality is a major topic in brain research. Numerous investigations have shown task dependent activation of focal brain areas, with most information based on time-averaged data due to methodological limitations. Ultra-fast quantitative EEG, especially in the newly developed combination with eye tracking (EnkephaloVision), is very suitable to follow activities of local electric circuits. This investigation in 57 subjects revealed transient focal frequency changes reaching up to more than 6000% of global median spectra power during cognitive and emotional challenges at frontal electrode positions. Recording epochs of 364 ms uncovered coherences with respect to focal brain areas and single frequencies, which are typically lost during averaged calculations. When averaging data over a whole scene, a least demanding challenge like viewing a boring animal video only activated the lateral frontal lobe, whereas solving brain-teasers and performance of mathematical calculations led to delta (modulated by acetylcholine) and theta (modulated by norepinephrine) increases in all brain regions in a statistically significant manner. In addition to delta and theta increases, performance of the Stroop test led to beta2 (related to GABAergic transmission) increases in the temporal lobe. The higher the mental demand the more brain regions were involved during 10 different challenges. There was no challenge which did not activate the lateral frontal brain in terms of increases of delta and theta spectral power. The results are in line with the view that the lateral frontal lobe is involved primarily during cognitive and emotional behavior related to activity changes of acetylcholine and norepinephrine.

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Section: Discussionsupporting

confidence: 56%

Section: Introductionmentioning

confidence: 99%

EnkephaloVision: Anatomical Functionality Indicated by Ultrashort Transient Regional EEG Spectral Power Changes during Cognitive and Emotional Challenges

Dimpfel¹,

Dipah²,

Gericke³

2016

WJNS

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“…Other authors also have recently documented higher delta values for subjects suffering from mild cognitive impairment in comparison to healthy volunteers and reported on further alterations typical for those seen in Alzheimer's disease [22]. Higher power in the delta frequency range indicates lower activity of the cholinergic transmitter system [23]. In animal lesion studies, increased delta activity has been reported after destruction of the Nucleus Basalis [24], the main production site of acetylcholine [25].…”

Section: Discussionmentioning

confidence: 83%

Neurophysiological Biomarker of Mild Cognitive Impairment

Dimpfel¹

2014

AAD

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Mild cognitive impairment is sometimes regarded as related to aging. However, statistically every second case turns into full dementia, which still is resistant to any treatment. It is therefore desirable to recognize deviations from normality as early as possible. This might be feasible by using quantitative EEG analysis in the presence of mental work. The present retrospective data analysis revealed a new quantitative biomarker indicating the degree of impairment. Current source density was calculated from 16 channel EEG using CATEEM ® software. Four different conditions were analyzed: relaxed state, performing a d2-concentration test, a calculation performance test and a memory test for 5 min each. Subjects older than 40 years were divided into two groups according to their DemTect score: 13 -18 (HC; n = 44) or 8 -12 (MCI; n = 45). Spectral power was chopped into six frequency ranges (delta, theta, alpha 1, alpha 2, beta 1 and beta 2). Average spectral power was enhanced in the MCI group in comparison to healthy subjects with respect to delta (p = 0.05) during relaxed state when all electrode positions were regarded. With respect to EEG recording during performance of three different psychometric tests it was recognized that mainly spectral changes during performance of the d2-concentration test were related to mild cognitive impairment. With regard to all electrode positions statistically significantly lower spectral power values were reached during the d2-test for delta (p = 0.001), theta (p = 0.0001) and alpha 1 waves (p = 0.08) in impaired subjects in comparison to healthy subjects. Regarding regions of interest increases of delta and theta power were seen in the fronto-temporal brain during performance of the d2-concentration test. These increases disappeared when looking at MCI data. In the centro-parietal region decreases of alpha and beta 1 power emerged, which were even larger in MCI subjects. No MCI-dependent changes were observed in the other two tests. A correlation was found between psychometric performance of the d2-test and the DemTect score (r = 0.51). MCI subjects had statistically significant worse performance in all three mental challenges in comparison to healthy volunteers. It is concluded that MCI can be characterized at an early stage by EEG recording in the relaxed state. High spectral delta and theta power in general and specifically at fronto-

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“…Many experimental works have shown that drugs affect EEG characteristics in humans and rodents in a similar manner [Dimpfel et al, 1992;Jongsma et al, 1998a,b Coenen andDimpfel, 2005]. In addition, a substantial body of studies suggest a relation between memory performance and EEG.…”

Section: Eeg and Epmentioning

confidence: 99%