István Katona Biography#

István Katona works as the Head of the Department of Molecular and Developmental Neurobiology at the Institute of Experimental Medicine, Hungarian Academy of Sciences in Budapest. His research aims to elucidate the molecular and structural principles as well as the physiological and pathophysiological significance of endocannabinoid signaling. In terms of his doctoral project in Tamás Freund's laboratory, he discovered that CB1 cannabinoid receptors are presynaptically located on axon terminals, where they control neurotransmitter release. Based on this observation in 1999, he proposed that endocannabinoids may function as retrograde synaptic messengers. Later he has also demonstrated that the major postsynaptically located endocannabinoid (2-AG)-synthesizing enzyme is DAGL-alpha, which exhibits a peculiar perisynaptic compartmentalization as a member of the perisynaptic machinery. To provide a framework for the overall physiological role of retrograde 2-AG signaling as the principal negative feed-back pathway of chemical synapses, he postulated the concept in a Nature Medicine review that this signaling pathway has evolved to function as a "synaptic circuit-breaker" to regulate network excitability. Recently, his team provided evidence for the pathophysiological consequences of the breakdown of this "synaptic circuit-breaker" in human temporal lobe epilepsy and in a mouse model of the Fragile X syndrome. At present, his team is focusing on the characterization of novel, phylogenetically-related endocannabinoid signaling pathways and investigate their physiological and pathophysiological significance.