Research in the Gall laboratory is focused on the cellular mechanisms of synaptic plasticity underlying learning and memory. Recent work has addressed the hypothesis that a form of synaptic plasticity thought to underlie memory, referred to as long term potentiation (LTP), depends on both remodeling of the synaptic cytoskeleton and a precise balance in signaling from a number of synaptic modulatory receptors. In particular, we find that among relays in limbic circuitry encoding episodic memory, there are differences in mechanisms of plasticity with endocannabinoid signaling required at one point and sexually dimorphic involvement of estrogen at another. Parallel studies are evaluating impairments in synaptic plasticity in fragile X syndrome model mice and testing the efficacy of therapeutics targetting modulatory signaling (e.g., estrogen, endocannabinoid, oxytocin) to enhance cognitive function. Ongoing projects are testing the effects of early life cannabinoid exposure on synaptic and cognitive function in adulthood, evaluating mechanisms through which oxytocin improves cognitive function in fragile X model mice, and identifying the synaptic bases of sexual dimorphism in hippocampus dependent learning. Procedures include evaluating learning behavior, synaptic/slice electrophysiology and quantitative microscopy (to evaluate synaptic receptors and signaling).