Susana Aznar Kleijn

​Head of Molecular Biology Section

Ph.D., cand.scient.

Contact: +45 38635940 /

My research comprises two parallel lines:

On one side, I am interested in understanding the serotonergic system's involvement in modulating the neural substrates implicated in executive function. Emphasis is on the serotonin 2A receptor's role in prefrontal cortex function through interaction with other receptor and neurotransmitter systems. By applying neuronal tracing, receptor autoradiography, intracellular pathway analyses, brain mapping  of neuronal and pathway activation by c-Fos stereological quantification, gene expression analyses and protein levels measurements in animal models, our aim is to elucidate how alterations in this receptor may be involved in the cognitive manifestations associated with neuropsychiatric and neurodegenerative diseases. Our focus is mainly on dopamine related disorders, like addiction, schizophrenia and Parkinson.

On the other side, we conduct studies on human samples from our Brain Bank, in order to find and validate disease-specific biological markers that may be potential candidates as biomarkers for Parkinson and other parkinsonism. Our aim is to provide clinicians with a disease-specific biomarker panel valid for use in the clinics. We believe that access to such a panel would be a strong tool for use in clinical trials, as well as provide clinicians with a much needed instrument for early differential diagnosis between Parkinson Disease from Multiple System Atrophy and other Parkinsonism. Our studies comprise biochemical, genetic, epigenomic and proteomic approaches with focus on neuroinflammatory and neurotrophic related processes.

Publications the last 5 years

Folke J, Rydbirk R,  Løkkegaard A, Salvesen L,  Hejl AM,  Starhof C, Bech S, Winge K, Christensen S, Østergaard Pedersen L, Aznar S, Pakkenberg B,  Brudek T. Distinct Autoimmune Anti-α-Synuclein Antibody Patterns in Multiple System Atrophy and Parkinson’s Disease. Frontiers in Immunology 2019, 2253

Villumsen M, Aznar S, Pakkenberg B, Brudek T, Jess T. Authors' response: Association between IBD and Parkinson's disease: seek and you shall find? Gut. 2019 Sep;68(9):1722. 

Elfving B, Müller HK, Oliveras I, Østerbøg TB, Rio-Alamos C, Sanchez-Gonzalez A, Tobeña A, Fernandez-Teruel A, Aznar S. Differential expression of synaptic markers regulated during neurodevelopment in a rat model of schizophrenia-like behavior. Prog Neuropsychopharmacol Biol Psychiatry. 2019 Jun 20;95:109669. 

Rydbirk R, Elfving B, Folke J, Pakkenberg B, Winge K, Brudek T, Aznar S. Increased prefrontal cortex interleukin-2 protein levels and shift in the peripheral T cell population in progressive supranuclear palsy patients. Sci Rep. 2019 May 23;9(1):7781. 

Villumsen M, Aznar S, Pakkenberg B, Jess T, Brudek T. Inflammatory bowel disease increases the risk of Parkinson's disease: a Danish nationwide cohort study 1977-2014. Gut. 2019 Jan;68(1):18-24.

Mora S, Merchán A, Vilchez O, Aznar S, Klein AB, Ultved L, Campa L, Suñol C, Flores P, Moreno M. Reduced cortical serotonin 5-HT2A receptor binding and glutamate activity in high compulsive drinker rats. Neuropharmacology. 2018 Dec;143:10-19. 

Betzer C, Lassen LB, Olsen A, Kofoed RH, Reimer L, Gregersen E, Zheng J, Calì T, Gai WP, Chen T, Moeller A, Brini M, Fu Y, Halliday G, Brudek T, Aznar S, Pakkenberg B, Andersen JP, Jensen PH. Alpha-synuclein aggregates activate calcium pump SERCA leading to calcium dysregulation. EMBO Rep. 2018 May;19(5). pii: e44617. 
Fomsgaard L, Moreno JL, de la Fuente Revenga M, Brudek T, Adamsen D,
Rio-Alamos C, Saunders J, Klein AB, Oliveras I, Cañete T, Blazquez G, Tobeña A,
Fernandez-Teruel A, Gonzalez-Maeso J, Aznar S. Differences in 5-HT2A and mGlu2
Receptor Expression Levels and Repressive Epigenetic Modifications at the 5-HT2A Promoter Region in the Roman Low- (RLA-I) and High- (RHA-I) Avoidance Rat
Strains. Mol Neurobiol. 2018 Mar;55(3):1998-2012.
Rydbirk R, Elfving B, Andersen MD, Langbøl MA, Folke J, Winge K, Pakkenberg B, Brudek T, Aznar S. Cytokine profiling in the prefrontal cortex of Parkinson's Disease and Multiple System Atrophy patients. Neurobiol Dis. 2017 Oct;106:269-278.

Merchán A, Navarro SV, Klein AB, Aznar S, Campa L, Suñol C, Moreno M, Flores
P. Tryptophan depletion affects compulsive behaviour in rats: strain dependent
effects and associated neuromechanisms. Psychopharmacology (Berl). 2017

Hervig ME, Jensen NCH, Rasmussen NB, Rydbirk R, Olesen MV, Hay-Schmidt A,
Pakkenberg B, Aznar S. Involvement of serotonin 2A receptor activation in
modulating medial prefrontal cortex and amygdala neuronal activation during
novelty-exposure. Behav Brain Res. 2017 May 30;326:1-12. 

Oliveras I, Sánchez-González A, Sampedro-Viana D, Piludu MA, Río-Alamos C,
Giorgi O, Corda MG, Aznar S, González-Maeso J, Gerbolés C, Blázquez G, Cañete T, 
Tobeña A, Fernández-Teruel A. Differential effects of antipsychotic and
propsychotic drugs on prepulse inhibition and locomotor activity in Roman high-
(RHA) and low-avoidance (RLA) rats. Psychopharmacology (Berl). 2017

Rydbirk R, Folke J, Winge K, Aznar S, Pakkenberg B, Brudek T. Assessment of
brain reference genes for RT-qPCR studies in neurodegenerative diseases. Sci Rep. 2016 Nov 17;6:37116.

Rasmussen NB, Olesen MV, Brudek T, Plenge P, Klein AB, Westin JE, Fog K,
Wörtwein G, Aznar S. 5-HT2A Receptor Binding in the Frontal Cortex of Parkinson's
Disease Patients and Alpha-Synuclein Overexpressing Mice: A Postmortem Study.
Parkinsons Dis. 2016;2016:3682936. 

Aznar S and Hervig MES. 2015. The 5-HT2A serotonin receptor in executive function: implications for neuropsychiatric and neurodegenerative diseases. ​Neuroscience and Biobehavioral Reviews 64 p. 63-82 (2016).​​

Klein AB, Ultved L, Adamsen D, Santini MA, Tobeña A, Fernandez-Teruel A, Flores P, Moreno M, Knudsen GM, Aznar S, Mikkelsen JD. 2014. 5-HT2A and mGluR2 receptor binding levels are related to differences in impulsive behaviour in the Roman Low- (RLA) and High (RHA) avoidance rat strains. Neuroscience 263:36-45.​