ABS 095: Registration of in vivo and ex vivo neuroimaging for applications in odor-place association learning in mouse piriform cortex

Rohan Meier ¹ , Rebecca Tripp ¹ , Max Seppo ¹ , Simon Daste ¹ ² , Alexander Fleischmann ¹

¹ Brown University
² Duke University

Van Wickle (2025) Volume 1, ABS095

Introduction: In vivo, functional imaging and ex vivo histology provide complementary approaches to studying the function and molecular composition of the brain. While methods to perform both in the same sample have been published, they are not generally applicable. The co-registration of these two imaging modalities enables the combined analysis of in vivo data on the activity, adaptation, and plasticity of neurons to be compared with the ex vivo data on their protein expression and cellular markers. We developed a multimodal registration technique that combines two-photon microscopy for the visualization of network activity over time and confocal microscopy for the high-resolution identification and characterization of neurons based on molecular identity. Our method relies on blood vessel labeling across modalities to provide a clear landmark for spatial registration. We then optimize registration algorithms for successful alignment and subsequent analysis. Finally, we use our technique to examine whether throughout odor-learning activity, neurons with greater change in function, or plasticity, map to differences in protein expression related to energy expenditure and synaptic strength in the olfactory cortex. We anticipate functional changes in the odor-responsive neuronal populations during an olfactory associative learning task and therefore hypothesize that molecular features will predict which neurons undergo such plasticity. To assess the molecular profiles of these neurons, we intend to stain for synaptophysin to assess synaptic strength and reactive oxygen species to evaluate mitochondrial function and overall cellular energy state. Using the registration protocol detailed above, the neurons imaged in vivo during the learning process will be matched to the same neurons’ energy expenditure and synaptic strength profiles post hoc to determine the relationship between function and molecular identity in plasticity.

Methods: Not published

Results: Not published

Discussion: Not published