Via Zoom Mr. Jordi Chanovas, a student in the Neural & Behavioral Science program and the laboratory of Dr. Juan Marcos Alarcon will present his thesis:

Gut microbiome contribution in neuron allocation and memory linkage

Trillions of microbes —comprising communities of bacteria, virus, fungi, and other microorganisms— inhabit the gastrointestinal tract. Known as gut microbiota, these microorganisms are central to human health. Growing evidence connects imbalances of microbial communities with several neurological and psychiatric conditions, and signals to the modulating role of gut bacteria on brain function, including learning and memory. Gut microbes impact synaptic plasticity as well as cognitive behavior. Yet, a comprehensive theory that bridges neuronal and behavioral correlates to explain microbiome impact on learning and memory is underdeveloped. Here, we propose to investigate whether gut dysbiosis alters the formation of neuronal ensembles recruited by memory (neuronal allocation) and, hence, disrupts the capacity to associate memory experiences (memory linkage). To test the hypothesis, we will deplete gut bacteria in mice giving a cocktail of antibiotics and study memory-associated neuronal allocation in the dorsal hippocampus (Specific Aim 1) and memory linkage of two place avoidance task experiences (Specific Aim 2). A combination of in vivo immediate-early gene tagging, and behavioral approaches will allow us to quantify neuronal ensemble size and degree of co-allocation for two related but distinct place avoidance memory tasks and their behavioral linkage when mice experience them in sequence. Success of this project entails a new mechanistic framework to research the gut-brain axis in terms of memory engrams, opening avenues to therapeutic manipulation of microbiome to target neurological and psychiatric conditions.