Dear All,

We cordially invite you to the Ph.D. seminar, which will be held on January 14, 2022 at 10.30 in the CN Conference Room (1st floor). The program includes 3 presentations:

Joanna Beck
Michał Niziołek
Patrycja Kruk

Information regarding speakers together with abstracts can be found below.

The seminar will be held in a hybrid mode. People in the CN Room (speakers and their supervisors) are asked to follow the safety rules.

Link to the meeting

https://zoom.us/j/99391829934?pwd=SWwxWjN3aldpRnNsQXppOXNtK0V5QT09

With best regards and wishes for a Happy New Year,

Anna Filipek & Anna Nowicka

Joanna Beck

Laboratory of Language Neurobiology

Supervisor: dr hab. Katarzyna Jednoróg

Title: “Letters and speech sounds associations in typical and atypical reading development”

Abstract:

The first and critical step in reading development is learning letter-speech sound (LS) associations. The pace of learning LS associations depends on orthographic transparency - the degree of regularity in LS correspondence, though learning trajectories in Polish are unknown. Successful acquisition of LS association is a predictor of later reading skills and left superior temporal cortex (STC) plays an important role in forming LS associations. Its disruption was implicated in dyslexia, though if it is genuine effect or a consequence of decreased reading experience is undetermined. Finally, little is known about the process LS association in the blind. To better understand LS integration in typical and atypical reading development (dyslexia and blindness) we conducted four experiments using behavioral methods and fMRI. Polish children master LS associations within two years of reading instruction, but LS automatization takes longer. Differences in brain activation to LS association can be found at a very early stage of reading instruction. Dyslexia significantly affects LS association in the left STC, with lower brain response to conflicting LS compared to both age and reading matched controls. LS integration occurs in the blind brain though it is different from the sighted, possibly reflecting their lower exposure to reading.

Michał Niziołek

Laboratory of Cytoskeleton and Cilia Biology

Supervisor:  dr hab. Dorota Włoga

Title: “Proximo-distal and circumferential differences in ciliary proteins’ localization in a ciliate Tetrahymena thermophila.”

Abstract:

Motile cilia are several micrometers long, microtubule-based hair-like cell protrusions. The ultrastructure and protein composition of cilia are highly evolutionarily conserved from protists to mammals. We have found that there are proximo-distal and circumferential differences in the localization of components of some ciliary complexes.

Tetrahymena paralogous proteins, CCDC146A and CCDC146B have complementary ciliary localization. CCDC146A localizes in the distal half of the cilium, whereas CCDC146B is present in the proximal part. When N-terminal fragments are exchanged between paralogs, chimeric proteins are present in the whole cilia. CCDC146A and CCDC146B interact with CCDC47C forming a minor complex positioned close to outer dynein arms (ODAs) and nexin-dynein regulatory complexes, and their lack differently affects cilia motility suggesting that the same ultrastructural defects may cause various phenotypic outcomes depending upon the position of the defect along the cilium length.

CCDC114 and CCDC151 are highly evolutionarily conserved proteins, subunits of the ODAs docking complex. The genome of Tetrahymena encodes 7 paralogs of CCDC114. These paralogs localize differently not only along the cilium length (cilium base, proximal and distal parts) but also at cilium circumference. Because during the power and recovery stroke, base, proximal, and distal parts of the cilium bend in their own way, we hypothesize that such differences are correlated with the presence of various protein paralogs.

Patrycja Kruk

Laboratory of Cell Biophysics

Supervisor: dr hab. Joanna Dzwonek, prof. IBD

Title: “Astrocytic CD44 deletion in the dentate gyrus influences epileptogenesis”

Abstract:

Epilepsy is one of the most common chronic neurological diseases affecting around 0.5-1.0% of the human population. The source of most cases of epilepsy is unknown. Highly expressed in astrocytes CD44 protein, a transmembrane receptor for hyaluronan, is believed to play an important role in reactive astrogliosis in pathological conditions in the brain. To study the CD44-depended astrocyte-neuron relationship in epileptogenesis, the kainic acid (KA) model of temporal lobe epilepsy (TLE) was used, where mice undergo intrahippocampal KA injections provoking status epilepticus and further recurrent seizures. Whereas wild-type mice injected with KA show similar to human neuropathological and electroencephalographic (EEG) TLE features, those with a previously activated conditional CD44 knock-out in astrocytic cells in the dentate gyrus develop a different seizure pattern. Their EEG recordings show the seizures they experience are more frequent than those in the control group, but their severity is lower. While control group mice experience more whole body clonic/clonic-tonic attacks, CD44 knock-out often does not show any behavioral symptoms of a seizure at all. These results indicate astrocytic CD44 plays a crucial role in epileptogenesis and seizure development and may provide a possible alternative pathway for future drug discovery.