Biology subjects

Koutsioumpa, C.

Publications and source records attributed to Koutsioumpa, C..

3 recordsLinked to original sources

bioRxiv2021

Mechanoreceptor synapses in the brainstem shape the central representation of touch

Mammals use glabrous (hairless) skin of their hands and feet to navigate and manipulate their environment. Cortical maps of the body surface across species contain disproportionately large numbers of neurons dedicated to glabrous skin sensation, potentially reflecting a higher density of mechanoreceptors that innervate these skin regions. Here, we find that disproportionate representation of glabrous skin emerges over postnatal development at the first synapse between peripheral mechanoreceptors and their central targets in the brainstem. Mechanoreceptor synapses undergo developmental refinement that depends on proximity of their terminals to glabrous skin, such that those innervating glabrous skin make synaptic connections that expand their central representation. In mice that do not sense gentle touch, mechanoreceptors innervating glabrous skin still make more powerful synaptic connections in the brainstem. We propose that the skin region a mechanoreceptor innervates controls refinement of its central synapses over development to shape the representation of touch in the brain.

neuroscience↗

bioRxiv2021

Comprehensive mapping of local and diaspora scientists: a database and analysis of 63951 Greek scientists

Research policy and planning for a given country may benefit from reliable data on both its scientific workforce as well as the diaspora of scientists for countries with substantial brain drain. Here we use a systematic approach using Scopus to generate a comprehensive country-level database of all scientists in Greece. Moreover, we expand that database to include also Greek diaspora scientists. The database that we have compiled includes 63951 scientists who have published at least 5 papers indexed in Scopus. Of those, 35116 have an affiliation in Greece. We validate the sensitivity and specificity of the database against different control sets of scientists. We also analyze the scientific disciplines of these scientists according to the Science Metrix classification (174 subfield disciplines) and provide detailed data on each of the 63951 scientists using multiple citation indicators and a composite thereof. These analyses demonstrate differential concentrations in specific subfields for the local versus the diaspora cohorts, as well as an advantage of the diaspora cohort in terms of citation indicators especially among top-impact researchers. The approach that we have taken can be applied to map also the scientific workforce of other countries and nations for evaluation, planning and policy purposes.

scientific communication and education↗

bioRxiv2019

PESCA: A scalable platform for the development of cell-type-specific viral drivers

Enhancers are the primary DNA regulatory elements that confer cell type specificity of gene expression. Recent studies characterizing individual enhancers have revealed their potential to direct heterologous gene expression in a highly cell-type-specific manner. However, it has not yet been possible to systematically identify and test the function of enhancers for each of the many cell types in an organism. We have developed PESCA, a scalable and generalizable method that leverages ATAC- and single-cell RNA-sequencing protocols, to characterize cell-type-specific enhancers that should enable genetic access and perturbation of gene function across mammalian cell types. Focusing on the highly heterogeneous mammalian cerebral cortex, we apply PESCA to find enhancers and generate viral reagents capable of accessing and manipulating a subset of somatostatin-expressing cortical interneurons with high specificity. This study demonstrates the utility of this platform for developing new cell-type-specific viral reagents, with significant implications for both basic and translational research.\n\nOne sentence summaryHighly paralleled functional evaluation of enhancer activity in single cells generates new cell-type-specific tools with broad medical and scientific applications.

neuroscience↗