Perceptual decision-making, in recent decades, has become one of the central topics in neuroscience. Combining behaviour with techniques for neural activity monitoring and modulation allows to study structures and mechanisms involved in the process. Elucidating its elements and functional connectivity will not only deepen our knowledge of this matter but also provide with information essential to answer more complex questions related to mechanisms guiding our perception of the world. The view on this topic has also been remodelled in recent years switching from seeing the brain as an observer of events to an active analyst. In the past various studies were carried out on the topic of perceptual decisionmaking, basing mainly on visual paradigms in humans and non-human primates. Thanks to developments in technology, genetics and behavioural paradigms, studies in rodents spanning through different sensory modalities are more readily implemented allowing for more in-depth analysis. In this thesis I developed and used auditory-based detection task to study perceptual decision-making on the example of temporal expectations in mice. Further, I combined this paradigm with chemogenetics to examine the results of modulation of activity in auditory cortex on sound detection in behaviour task.Finally, during electrophysiological recordings from auditory cortex, I looked at effects of modulation of neural activity using chemogenetics. These acute experiments were performed in anaesthetized mice. The results have proven that mice model is a highly useful tool in the study of perceptual decision-making, allowing for combination of behavioural task with neural activity monitoring and modulation. In the behavioural task the influence of foreperiod duration on reaction time was not confirmed but a correlation between foreperiod presentation ratio and reaction time was observed.. Implementation of chemogenetics in behavioural paradigm influenced hit rate and reaction time dynamics only for some of the higher sound intensities, therefore not providing confirmation of effect of used technique on behaviour. In electrophysiological recordings, statistically significant changes in levels of neural activity after activation of chemogenetics were reported for both sound- evoked and no-sound related activity in auditory cortex. Altogether, the obtained results do not provide confirmation of presented research theses which presumed the importance of auditory cortex for perceptual decision-making. However, due to the complexity of the matter in question , further studies are needed.
|Date of Award||6 Jun 2019|
- University Of Strathclyde
|Sponsors||University of Strathclyde|
|Supervisor||Shuzo Sakata (Supervisor) & Trevor Bushell (Supervisor)|