Watergate

Fear and extinction memories co-exist in the brain and compete for expression. In the context of fear disorders, extinction therapy is not always effective and fear memories can reemerge. Internal states, such as thirst, can significantly interfere with fear extinction via the paraventricular nucleus of the thalamus (PVT). Importantly, PVT sends projections to the CA1 part of the ventral hippocampus (vCA1), which plays a key role in the encoding and retrieval of emotionally salient contextual memories. Both the PVT and vCA1 are modulated by the hydration status. The WaterGate project will investigate how hydration states modulate the PVT-vCA1 circuit and influence extinction memory retrieval. We hypothesise that distinct neuronal populations in these regions, activated by thirst or satiety, modulate memory retrieval via projections to the amygdala and nucleus accumbens. Using ex vivo and in vivo electrophysiology, optogenetics, and viral strategies in mice (tag neuron), we will characterise these populations and identify circuits and electrophysiological patterns linking internal states to emotional memory regulation. Understanding how internal states influence brain circuit dynamics underlying emotional memory processes may provide new insights in the treatment of fear disorders.