ليلا كامياب گورابسري

Morphine is a natural opioid which is administered in preterm infants as a pain reliever treatment. Animal models have opened the door to a better understanding of the neurobiology of brain disorders and increased our ability to eva‎luate novel treatments. Resting-state functional magnetic resonance imaging (rs-fMRI) allows us to eva‎luate the functional connecivity between different brain regions, and its application in rodents affords researchers a powerful tool to directly assess the effects of various pharmacological, lesion, and/or disease on known neural circuits within highly controlled settings. There are very few studies eva‎luating the long-term effects of morphine administration on the brain. FMRI image processing tools are designed for human subjects, and the standard atlases for the human brain are qualitatively and quantitatively at a higher level than the available resources for rodents. So, all pre-processing and registration of non-human fMRI images are associated with many challenges and the process is very time-consuming. In this thesis, the fMRI data of 24 rats were used, one group of which was injected with morphine and the other group was administered only saline. The data was received from Harvard University and has been processed and analyzed for the first time in this thesis, and were pre-processed using FSL and MRIcroGL software. In clinical applications, the principle is based on the simplicity of the analysis and the comprehensibility of their results. Therefore, using pre-processed data, we eva‎luate the functional connectivities between different brain regions based on Pearson's linear correlation method, which is a simple yet widely used statistical method. By the use of the non-parametric Wilcoxon rank sum statistical test, we identified the regions which had a significant difference in the connectivity measure between the two groups. Also, we used the KNN classification algorithm with the leave-one-out coss validation method, in order to classify the rats into two groups of morphine and saline (control), to check significant functional characteristics with statistical test. We found that the connections between the amygdala-hippocampus, hippocampus-hypothalamus, amygdala-olfactory cortex and several connections between other areas were stronger in the morphine group than in the control or saline groups.

مورفين , اثر درازمدت , ارتباطات عملكردي , طبقه¬بندي KNN , موش صحرايي نوزاد

Morphine , Long-term Impact , Functional Connectivity , KNN Classification , Infant Rats

Laila Kamyab Gourabsari

Ahmad Ayatollahi