Phd in PHD PROGRAM IN BEHAVIORAL NEUROSCIENCE

Thesis title: From Capacity to Stability: Exploring the Mechanisms that Shape Memory

Memory can be challenged in two main ways: by increasing the amount of information to be retained or by extending the retention interval. Using the Different/Identical Object Test (DOT/IOT), it has been shown that male and female CD1 mice can retain up to six distinct objects in short-term memory, and that exceeding this limit leads to a state of memory overload. Under such demanding conditions, the brain appears to engage alternative neural pathways, suggesting that distinct mechanisms are recruited depending on memory load. To investigate the mechanisms underlying the expansion of memory span, we focused on cortico-striatal networks, critically modulated by dopaminergic signaling. This approach allowed us to examine how memory capacity can be pharmacologically enhanced and to highlight the role of specific circuits in supporting it. To further explore how this memory is stabilized over time, we used sex differences in high memory load consolidation as a model. We investigated the physiological factors involved in sleep-dependent processes, emphasizing how sleep architecture can support effective consolidation in conditions of high memory load. Overall, this work examines memory from short-term expansion to long-term consolidation, highlighting load- and sex-dependent circuit mechanisms. Understanding these processes provides insights into cognitive flexibility and may inform strategies for addressing memory impairments in neurological disorders.