Dr. Sieghart studied chemistry at the University of Vienna, Austria, and made his PhD in biochemistry (1973) with Prof. Hans Tuppy (Department of Biochemistry, Univ. Vienna, Austria), working on yeast mitochondria.
From 1973-1976, he joined Prof. Manfred Karobath at the Chemical Laboratory of the University Clinic for Psychiatry, Vienna, as a postdoc. This laboratory later on became re-named to „Section of Biochemical Psychiatry“. During this first postdoc, he predominantly worked on taurine transport and release in the nervous system, as well as on the dopamine-sensitive adenylyl cyclase.
From 1976-1978, Dr. Sieghart did a second postdoc with Prof. Paul Greengard, Yale University, New Haven, CT, USA. During that time he worked on calcium and cAMP-dependent protein phosphorylation and their involvement in secretion.
1978 Dr. Sieghart returned to the Section of Biochemical Psychiatry, University Clinic for Psychiatry, Vienna, as an assistant professor, and started to work on a glutamate-dependent protein phosphorylation.
1980 Prof. Manfred Karobath left the Section of Biochemical Psychiatry to become head of Preclinical Research at Sandoz in Basle, Switzerland. Dr. Sieghart became his successor and directed the Section of Biochemical Psychiatry from 1980-2001.
1980-1990 In 1980, the Section of Biochemical Psychiatry consisted of two laboratories: A basic research laboratory and a clinical chemistry laboratory. In the basic research laboratory, Dr. Sieghart developed his own line of research on GABAA receptors, their heterogeneity, structure, function, regional and cellular distribution in the brain, and pharmacology.
But in parallel, he also directed the clinical chemistry laboratory performing blood glucose, electrolytes, blood enzymes, differential blood cell diagnostics, urine determinations, etc., for patients of the University Clinic for Psychiatry for more than 10 years. In 1990, this clinical chemistry laboratory became integrated into the Central Clinical Chemistry Laboratory of all University Hospitals at the „Allgemeines Krankenhaus“ in Vienna, Austria.
1980-2001 Dr. Sieghart also supervised more specialized anticonvulsant and Lithium determinations, established and supervised drug of abuse determinations, hormone determinations and molecular genetic investigations for the University Clinic for Psychiatry. These more specialized determinations became integrated into the Central Clinical Chem. Laboratory of the Allgemeines Krankenhaus, Vienna, in 2001.
1999 Based on his scientific achievements and his publications at the Section of Biochemical Psychiatry, Dr. Sieghart joined the newly founded Center for Brain Research of the Medical University of Vienna as a group leader in 1999.
2002 Dr. Sieghart was appointed Full Professor for Biochemical and Molecular Pharmacology of the Nervous System and Head of the Department for Biochemistry and Molecular Biology of the Center for Brain Research, Medical University of Vienna. During the next 10 years he significantly contributed to teaching of neuroscience students of the Center and made major contributions to the scientific output of his Department and the Center for Brain Research.
2011 On October 1, Dr. Sieghart retired from this position after having reached the age limit of Austria for this position and became Guest Professor at the Center for Brain Research, Medical University Vienna.
Nevertheless he continued to direct his Department until July 25, 2013, when his successor, Tibor Harkany, was appointed Professor at the Center for Brain Research and Head of the Department that has been directed by Prof. Sieghart for nearly 12 years. At that time, the Department was re-named into „Department of Molecular Neurosciences“.