@article {3095, title = {Feature extraction and classification for pupillary images of rats}, year = {2018}, pages = {88--91}, type = {Short Paper}, address = {Szeged, Hungary}, abstract = {

The investigation of the pupillary light reflex (PLR) is a well-known method to provide information about the functionality of the autonomic nervous system. Pupillometry, a non-invasive technique, was applied in our lab to study the schizophrenia-related PLR alterations in a new selectively bred rat substrain, named WISKET. The pupil responses to light impulses were recorded with an infrared camera; the videos were automatically processed and features were extracted. Besides the classical statistical analysis (ANOVA), feature selection and classification were applied to reveal the significant differences in the PLR parameters between the control and WISKET animals.

}, url = {http://www.inf.u-szeged.hu/~cscs/pdf/cscs2018.pdf}, author = {Kalrm{\'a}r, G and B{\"u}ki, A and Kekesi, G and Horv{\'a}th, G and Ny{\'u}l, LG} } @article {3094, title = {Impaired pupillary control in {\textquotedblleft}schizophrenia-like{\textquotedblright} WISKET rats. Autonomic Neuroscience: Basic and Clinical.}, journal = {Autonomic Neuroscience: Basic and Clinical}, volume = {213}, year = {2018}, month = {2018 September}, pages = {34-42}, publisher = {Elsevier}, type = {Journal Article}, chapter = {34}, abstract = {

Patients with schizophrenia show impairments in autonomic regulation, including pupillomotor control. The aim of this study was to explore the changes of pupillary light reflex in a new substrain (WISKET) with several schizophrenia-like alterations.

Male WISKET rats housed individually (for four weeks) and treated with ketamine (for 3 {\texttimes} 5 days) after weaning and naive group-housed Wistar rats (controls) were involved in the study. The pupillary light reflex was studied in two series after sedation (diazepam) or anesthesia (chloral hydrate). Video recordings were evaluated with custom made video analyzer software.

Several significant changes were observed between the two groups: the initial and minimum pupil diameters were greater, the degree of the constriction was lower, and the flatness of the curve and the total duration of constriction were shorter in the sedated WISKET rats. No other pupillary parameters (latency, amplitude and redilation) showed significant alterations.

Chloral hydrate anesthesia prolonged the constriction and redilation processes compared to the sedated animals, and diminished the differences between the groups.

In conclusion, WISKET rats showed disturbances in the pupillary light reflex, suggesting a general shift of autonomic balance towards a sympathetic predominance. The results provide further evidence to support the validity of WISKET rats as a complex, chronic animal model of schizophrenia.

}, doi = {https://doi.org/10.1016/j.autneu.2018.05.007}, author = {B{\"u}ki, A and Kalm{\'a}r, G and Kekesi, G and Benedek, G and Ny{\'u}l, LG and Horv{\'a}th, G} } @article {3093, title = {Image processing-based automatic pupillometry on infrared videos.}, journal = {Acta Cybernetica}, volume = {23}, year = {2017}, month = {2017}, pages = {599-613}, publisher = {Szegedi Tudom{\'a}nyegyetem / University of Szeged}, type = {Journal Article}, chapter = {599}, address = {Szeged}, abstract = {

Pupillometry is a non-invasive technique that can be used to objectively characterize pathophysiological changes involving the pupillary reflex. It is essentially the measurement of the pupil diameter over time. Here, specially designed computer algorithms provide fast, reliable and reproducible solutions for the analysis. These methods use a priori information about the shape and color of the pupil. Our study focuses on measuring the diameter and dynamics of the pupils of rats with schizophrenia using videos recorded with a modified digital camera under infrared (IR) illumination. We developed a novel, robust method that measures the size of a pupil even under poor circumstances (noise, blur, reflections and occlusions). We compare our results with measurements obtained using manual annotation.

}, url = {http://cyber.bibl.u-szeged.hu/index.php/actcybern/article/view/29}, author = {Kalm{\'a}r, G and B{\"u}ki, A and Kekesi, G and Horv{\'a}th, G and Ny{\'u}l, LG} }