TY - THES ID - 134987528 TI - The Role of the Lateral Posterior Nucleus of the Thalamus in Sensory Selection in Mice: Visual cortical activity with silenced LP AU - Vingerhoets, Lotte AU - Bonin, Vincent AU - Ayaz, Asli AU - KU Leuven. Faculteit Wetenschappen. Opleiding Master of Biology (Leuven) PY - 2022 PB - Leuven KU Leuven. Faculteit Wetenschappen DB - UniCat UR - https://www.unicat.be/uniCat?func=search&query=sysid:134987528 AB - Throughout the day we receive a constant flow of multisensory inputs. Therefore, the brain needs to select relevant sensory information and ignore the distracters to be able to produce a proper behavioural response. This is an active process called sensory selection. However, the question “How does the brain select between relevant and irrelevant information?” remains unanswered. In this thesis, I took a first step toward studying the role of the lateral posterior nucleus (LP) of the thalamus in sensory selection in mice. LP is a higher-order thalamic nucleus with reciprocal connections with primary and higher cortical areas. In addition to relaying information, it can combine information from multiple regions. This suggests that it is uniquely positioned to modulate cortical processing. However, its contribution to sensory selection remains poorly understood. This thesis had three aims: 1) reliable targeting of LP using stereotaxic injections 2) retinotopic mapping of higher visual areas using intact skull wide-field imaging and 3) characterize the impact of chemogenetic silencing of LP on population dynamics in cortical visual areas. To achieve this aims, we performed Cholerin toxin subunit B tracer injections. Further, we made retinotopic maps of the visual cortex and silenced LP chemogenetically during stimulation of the visual cortex. As last, we injected a halorhodopsin driving virus into LP to check its expression and performed a preliminary experiment of optognetic silencing. Together, results showed that: 1) viral injection into LP is possible with great caution and precision, 2) that retinotopic mapping through an intact skull is reliable, and 3) that chemogenetic silencing is probably not the most effective method for the scope of this project, as examining sensory selection would require greater spatial precision and temporal control during silencing. ER -