Experimental Neurobiology Unit

RP-HPLC Analytical unit - Neurochemistry and behavior

Expertise

The Reversed-Phase Ultra-High-Performance Liquid Chromatography (RP-UHPLC) Unit of the Laboratory of Neurochemistry and Behavior is an analytical task force that holds considerable expertise in the field of neurochemical analysis of different biogenic amines and metabolites in biofluids and brain tissue samples.

More specifically, we quantitatively measure the levels of (nor)adrenaline, dopamine, serotonin and their main metabolites (3-methoxy-4-hydroxyphenylglycol (MHPG), 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), and, 5-hydroxyindoleacetic acid (5-HIAA)) in serum/plasma/urine/cerebrospinal fluid (CSF) or frozen brain tissue samples of (a) (transgenic) rodent models (preclinical level), or, (b) patients (clinical level).

We primarily focus on miscellaneous neurodegenerative conditions, such as:

  • Alzheimer’s disease (AD);
  • frontotemporal dementia;
  • Parkinson’s disease;
  • dementia with Lewy bodies;
  • amyotrophic lateral sclerosis;
  • multiple sclerosis;

and related conditions, such as Down syndrome.

By applying this technique, for instance, neurotransmitter fluctuations in behaviorally perturbed dementia patients (aggression, depression, other neuropsychiatric symptoms) can be monitored, pharmacological interventions in specific mice models can be evaluated, or, the additional discriminative value of biogenic amines combined with traditional AD biomarkers might be investigated.

Equipment

This research unit is fully equipped with one optimized AlexysTM Dual Monoamines Analyzer with electrochemical detection (Antec Leyden BV, Zoeterwoude, The Netherlands). This device comprises two LC110 pumps, operating at an isocratic flow rate of 40µL/min. Samples (5 µL) are loaded with an AlexysTM AS 100 Autosampler on microbore ALF-125 columns (250 mm × 1 mm, C18, 3  µm particle size) maintained at a constant temperature of 36°C.

The Decade II electrochemical detector is equipped with thin layered electrochemical VT03 flow cells each fitted with a glassy carbon 0.7 mm working electrode and an in situ Ag/AgCl (ISAAC) reference electrode. Integration of chromatograms (41 minutes runtime) is performed with channel integration M018/EN25B Clarity software (DataApex Ltd., Prague,The Czech Republic). We use a fast and simple sample preparation protocol for both serum/plasma/CSF and brain tissue samples.

Our second Alexys Neurotransmitter Analysis device has recently been adapted to a RP-UHPLC setting, using one LC110S pump delivering backpressures up to 700 bar. Separation is achieved by using a short 15cm Waters Acquity Column (BEH C18, 1mm diameter, particle size 1.7µm), delivering optimal performances for monoamine analysis. Total runtime for each sample is under 20 minutes after which all 8 monoamines and metabolites are detected.

Interestingly, both devices can be (relatively easy) adapted or customized for analyses of other neurochemical compounds, such as GABA, glutamate, acetylcholine/choline, glutathione and nitrotyrosine.

Samples

Cerebrospinal fluid (CSF); serum; plasma; brain tissue; urine (of rodent or human origin)

Project examples

“Neurochemical characterization of behavioral disturbances in dementia”

“Unraveling the monoaminergic pathogenesis of frontotemporal dementia and amyotrophic lateral sclerosis”

“The noradrenergic system in Down syndrome with/without Alzheimer’s disease: the discriminative role of serum MHPG”

“Defining the prefrontal monoaminergic neurotransmission in frontotemporal dementia compared to Alzheimer’s disease”

“Monoaminergic brain topochemistry in Alzheimer’s disease versus healthy elderly”

“The serotonergic system and ageing”

Selected publications

  • Nguyen, A.T., Aerts, T., Van Dam, D., De Deyn, P.P. (2010) Biogenic amines and their metabolites in mouse brain tissue: development, optimization and validation of an analytical HPLC method. J. Chromatogr. B. 878, 3003-3014.
     
  • Van Dam, D., Vermeiren, Y., Aerts, T., De Deyn, P.P. (2014) Novel and sensitive reversed-phase high-pressure liquid chromatography method with electrochemical detection for the simultaneous and fast determination of eight biogenic amines and metabolites in human brain tissue. J. Chromatogr. A. 1353, 28-39.
     
  • Vermeiren, Y., Van Dam, D., Aerts, T., Engelborghs, S., De Deyn, P.P. (2014) Monoaminergic neurotransmitter alterations in postmortem brain regions of depressed and aggressive patients with Alzheimer’s disease. Neurobiol. Aging. 35(12): 2691-2700.
     
  • Vermeiren, Y., Van Dam, D., Aerts, T., Engelborghs, S., Martin, JJ., De Deyn, P.P. (2015) The monoaminergic footprint of depression and psychosis in dementia with Lewy bodies compared to Alzheimer’s disease. Alzheimers Res. Ther. 7:7, DOI 10.1186/s13195-014-0090-1.
     
  • Dekker, A.D., Coppus, A.M.W., Vermeiren, Y., Aerts, T., van Duijn, C.M., Kremer, B.P., Naudé, P.J.W., Van Dam, D., De Deyn, P.P. (2015) Serum MHPG strongly predicts conversion to Alzheimer’s disease in behaviorally characterized subjects with Down syndrome. J. Alzheimers Dis. 43(3), 871-891.

  • Vermeiren, Y., De Deyn, P.P. (2017) Targeting the norepinephrinergic system in Parkinson’s disease and related disorders: the locus coeruleus story. Neurochem. Int. 102: 22-32.

  • Dekker, A.D., Vermeiren, Y., Carmona-Iragui, M., Benejam, B., Videla, L., Gelpi, E., Aerts, T., Van Dam, D., Fernández, S., Lleó, A., Videla, S., Sieben, A., Martin, J.-J., Netherlands Brain Bank, Blesa, R., Fortea, J., De Deyn, P.P. (2018) Monoaminergic impairment in Down syndrome with Alzheimer’s disease compared to early-onset Alzheimer’s disease. Alzheimers Dement. (Amst). 10: 99-111.

  • van der Zee, S., Vermeiren, Y., Fransen, E., Van Dam, D., Aerts, T., Gerritsen, M.J., Spikman, J.M., van Laar, T., De Deyn, P.P. (2018) Monoaminergic markers across the cognitive spectrum of Lewy body disease. J. Parkinsons Dis. 8(1): 71-84.

  • Janssens, J., Vermeiren, Y., Fransen, E., Aerts, T., Van Dam, D., Engelborghs, S., De Deyn, P.P. (2018) Cerebrospinal fluid and serum MHPG improve Alzheimer’s disease versus dementia with Lewy bodies differential diagnosis. Alzheimers Dement. (Amst). 10: 172-181.

  • Janssens, J., Atmosoerodjo, S.D., Vermeiren, Y., Absalom, A.R., den Daas, I., De Deyn, P.P. (2019) Sampling issues of cerebrospinal fluid and plasma monoamines: investigation of the circadian rhythm and rostrocaudal concentration gradient. Neurochem. Int., In Press, doi: 10.1016/j.neuint.2019.04.015.