Biology subjects

Georgiou, E.

Publications and source records attributed to Georgiou, E..

3 recordsLinked to original sources

bioRxiv2024

A toolbox for genetic targeting of the claustrum

The claustrum (CLA), a subcortical nucleus in mammals, essentially composed of excitatory projection neurons and known for its extensive connections with the neocortex, has recently been associated with a variety of functions ranging from consciousness to impulse control. However, research on the CLA has been challenging due to difficulties in specifically and comprehensively targeting its neuronal populations. In various cases, this limitation has led to inconsistent findings and a lack of reliable data. In the present work, we describe the expression profile of the Smim32 gene, which is almost exclusively transcribed in excitatory neurons of the CLA and the endopiriform nucleus, as well as in inhibitory neurons of the thalamic reticular nucleus. Leveraging this unique expression pattern, we developed a series of Cre- and Flippase-expressing knockin and BAC transgenic mouse lines with different expression profiles. With these novel tools in hand, we propose new standards for the interrogation of CLA function.

neuroscience↗

bioRxiv2023

DNA Origami Lipid Membrane Interactions Defined at Single-Molecular Resolution

Rigid DNA nanostructures that bind to floppy bilayer membranes are of fundamental interest as they replicate biological cytoskeletons for synthetic biology, biosensing, and biological research. Here, we establish principles underpinning the controlled interaction of DNA structures and lipid bilayers. As membrane anchors mediate interaction, more than 20 versions of a core DNA nanostructure are built each carrying up to five individual cholesterol anchors of different steric accessibility within the 3D geometry. The structures binding to membrane vesicles of tunable curvature is determined with ensemble methods and by single-molecule localization microscopy. This screen yields quantitative and unexpected insight on which steric anchor points cause efficient binding. Strikingly, defined nanostructures with a single molecular anchor discriminate effectively between vesicles of different nanoscale curvatures which may be exploited to discern diagnostically relevant membrane vesicles based on size. Furthermore, we reveal anchor-mediated bilayer interaction to be co-controlled by non-lipidated DNA regions and localized membrane curvatures stemming from heterogenous lipid composition, which modifies existing biophysical models. Our study extends DNA nanotechnology to control interactions with bilayer membranes and thereby facilitate the design of nanodevices for vesicle-based diagnostics, biosensing, and protocells.

biophysics↗

bioRxiv2021

The relationship between intelligence and orientation discrimination skills

We investigate the notion that basic visual information is acting as a building block for more complex cognitive processes in humans. Specifically, we measured individual visual orientation discrimination thresholds to report significant correlations against the total standardised intelligence quotient (IQ), verbal-IQ and non-verbal IQ scores evaluated using the Wechsler Abbreviated Scale of Intelligence Second Edition (WASI-II) test battery comprising Verbal Reasoning, Block Design, Similarities and Matrix Reasoning subtests (N=92). A multiple linear regression analysis showed that participants performance in our visual discrimination task, could be explained only by individual scores in Verbal Reasoning which quantifies the ability to comprehend and describe words and Matrix Reasoning, which evaluates general visual processing skills including abstract and spatial perception. Our results demonstrate that low-level visual abilities and high-level cognitive processes are more tightly interwoven together than previously thought and this result could pave the way for further research on how cognition can be defined by basic sensory processes.

neuroscience↗