Interest

The biology of brain development and psychiatric disorders

​Projects

Preterm birth

Preterm birth is associated with an increased risk of brain injury, persistently smaller brain volume and cognitive deficits. However, the relationship between these abnormalities and structural, as well as molecular changes and functions, remains elusive. Using design based stereological methods and a well-established pig model we will evaluate the effect of preterm birth on brain parameters such as regional volumes and surface areas.

Schizophrenia

Dopamine 2 receptor (DRD2) is of major interest to the pathophysiology of schizophrenia both as a target for antipsychotic drug action as well as a schizophrenia-associated risk gene. The dopamine 1 receptor (DRD1) is thought to mediate some of the cognitive deficits in schizophrenia, including impairment of working memory that relies on normal dorsolateral prefrontal cortex (DLPFC) function. To better understand the association of dopamine receptors with schizophrenia, we studied the expression of three DRD2 splice variants and the DRD1 transcript in DLPFC, hippocampus and caudate nucleus in a large cohort of subjects, including patients with schizophrenia, affective disorders and non-psychiatric controls, and examined genotype-expression associations of 278 SNPs located in or near DRD2 and DRD1 genes.
Accepted for publications in Molecular Psychiatry, 2013

Decreased parvalbumin expression is a hallmark of the pathophysiology of schizophrenia and has been associated with abnormal cognitive processing and decreased network specificity. It is not known whether this decrease is due toreduced expression of the parvalbumin protein or degeneration of parvalbumin-positive interneurons (PV+ interneurons). In this study, we examined PV+ expression in two rat models of cognitive dysfunction in schizophrenia: the environmental social isolation (SI) and pharmacological neonatal phencyclidine (neoPCP) models. Using a stereological method, the optical fractionator, we counted neurons, PV+ interneurons, and glial cells in the medial prefrontal cortex (mPFC) and hippocampus (HPC).
Published in J. Neurochem. (2013) Feb; 124(4):548-57

Publications

1. Karlsen,A.S., Kaalund,S.S., Moller,M., Plath,N., & Pakkenberg,B. Expression of presynaptic markers in a neurodevelopmental animal model with relevance to schizophrenia. Neuroreport 24, 928-933 (2013).

2. Kaalund,S.S. et al. Differential expression of parvalbumin in neonatal phencyclidine-treated rats and socially isolated rats. J. Neurochem. 124, 548-557 (2013).

3. Kaalund S.S. et al. Contrasting Changes in DRD1 and DRD2 Splice Variant Expression in Schizophrenia and Affective Disorders, and Associations with SNPs in Postmortem Brain. [Accepted for publication in Molecular Psychiatry].

4. Kaalund,S.S. et al. Investigation of 4q-deletion in two unrelated patients using array CGH. Am. J. Med. Genet. A 146A, 2431-2434 (2008).