Understanding the developing brain

Theofanis Karayannis recently joined the Brain Research Institute. With his expertise in the development of neuronal circuits he is a great addition to the team. We interviewed the new assistant professor about what attracted him to studying interneurons and about his motivation to join the “microcosm of neurosciences”.

ZNZ News: What is your research topic?
Theo Karayannis: I am intrigued by the complexity of the brain and the super Karayannis_150x150intricate network of connections between a diverse set of cells that wire up with amazing specificity. My work aims at understanding how the brain develops, how its circuits get formed and how the influence of environmental stimuli can help shape these processes. More specifically, my work has focused on GABA-ergic inhibitory interneurons, a diverse class of cells important for the development and function of the brain. It is my hope that my work will not only reveal the mechanisms of the making of the healthy brain, but also shed light on how developmental perturbations can lead to brain disorders that appear later in life. To get at the above issues I utilize genetics, as well as anatomical and functional methods.

What is an important contribution of your research?
Together with colleagues in the group of Prof. Fishell at NYU Neuroscience Institute, I have been able to show that early electrical activity plays an important role in the development and connectivity of selected cortical interneurons and that it is key to how these neurons embed in the circuits. In addition, through genetic screens we have also identified a novel synaptic protein that seems to have a differential role in synapses depending on whether they operate in a fast or a slow timescale (i.e. the GABA-ergic versus the dopaminergic system). Interestingly, this protein may play a role in neurodevelopmental disorders as we find that this gene is disrupted in humans suffering from a variety of brain ailments and observe behavioral phenotypes in mice upon removal of the gene.

What attracted you to the Brain Research Institute?
Not only is it a great institute for neurosciences, but the groups address a very diverse set of scientific questions by using a breadth of approaches ranging from molecular to systems neuroscience. It is a true microcosm of neuroscience and I look forward to working with the other Institute members to understand how the brain gets built and how it functions.

What can you tell us about your future research plans?
My immediate research plans will build on my previous findings and aim at understanding firstly the intracellular molecular pathways triggered in cortical interneurons by early sensory signals, and secondly, how these signals propagate through the early interneuron network in vivo. This work will provide us with cell type- and pathway-specific interactions early in life that are key in regulating the proper wiring of the developing primary sensory cortices. These sensory areas are considered to be the first station of peripheral signals on their route through the cortex, which then propagate to higher order multisensory areas where decisions are made about the organism’s reaction. The long-term goal of the lab is to understand how that takes place in the developing brain and how it can go awry in neurodevelopmental disorders.

Find more information about Prof. Dr. Theofanis Karayannis here

Image: Upper left: A superficial cortical interneuron in the somatosensory cortex of a P21 mouse brain, labeled by in utero electroporation, using a Dlx5/6eGFP plasmid. This cell is immunopositive for the marker reelin (red).  (Courtesy Prof Theofanis Karayannis), other images are creative variants of the upper left image.