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%0 Thesis %A Doerenkamp, Kerstin %T “Multisensory integration in superior colliculus and primary visual cortex of awake behaving mice” %I RWTH Aachen University %V Dissertation %C Aachen %M RWTH-2024-10606 %P 1 Online-Ressource : Illustrationen %D 2024 %Z Veröffentlicht auf dem Publikationsserver der RWTH Aachen University %Z Dissertation, RWTH Aachen University, 2024 %X Having multiple senses is essential for survival, since each sense is optimally suited to detect a different type of stimulus. When combining the information gained from multiple senses, more is revealed about the nature of an object. The response to such a multisensory combination can often even exceed the sum of its unimodal components. This synergy of sensory responses has been shown repeatedly in the multisensory area superior colliculus (SC). Previous experiments have shown that combining multiple sensory modalities can result in an increased performance in behavioural tasks. This thesis aims to investigate the neural origin for this increased performance. As a first step to unravelling how multisensory stimuli are represented and integrated in the brain, this study will focus on sensory responses in the visual system. Three essential areas of the mouse visual system are investigated: the primary visual cortex (V1), the superficial part of the superior colliculus (optic SC), and the deep part of the superior colliculus (deep SC). While the V1 and the optic SC are considered unisensory visual areas, the deep SC has been acknowledged as a multisensory area. In the first part of this study, multisensory responsiveness was compared between different areas of the visual system. Mice were presented with visual, tactile and auditory stimuli, while neuronal activity was recorded in V1 and SC simultaneously using high-density Neuropixels electrodes. The unisensory areas V1 and optic SC showed a surprisingly high occurrence of multisensory integration that was almost on par with the multisensory area deep SC. However, responses to nonvisual stimuli alone were much rarer and often had longer latencies in V1 and optic SC, indicating that crossmodal responses in unisensory areas were not as meaningful as in a multisensory area like the deep SC. In the second part, the effect of training mice on a visuotactile discrimination task on the multisensory responsiveness was investigated. Training caused a general reduction of the response strength, coupled with a decrease of the amount of responsive neurons in the SC. Additionally, multisensory enhancement was strongly reduced in trained mice, while multisensory depression was not affected by training. These changes suggest that training improves the accuracy of the stimulus detection by decreasing sensory responses that are not necessary for solving the behavioural task. %F PUB:(DE-HGF)11 %9 Dissertation / PhD Thesis %R 10.18154/RWTH-2024-10606 %U https://publications.rwth-aachen.de/record/996426