http://tdlc.ucsd.edu/research/DNS/speakers/Lynch.html Gary Lynch from UC Irvine presents on "The cell biology of cognition: From synaptic encoding to episodic memory" Encoding a series of events into a single episode or narrative allows the brain to efficiently organize the large amounts of information generated during routine encounters with real world environments. This process, which is fundamental to cognition, has become a topic of intense interest for neuroscientists with recent work emphasizing a key role for the hippocampus. Ongoing rodent studies using transient silencing of discrete areas confirm the basic idea that separate inputs convey information about cue identity (‘what’) and spatial relationships (‘where’), with a downstream region adding timing (‘when’). Surprisingly, a combination of methods revealed that the three types of connections are very different with regard to signal processing and learning related plasticity; the ‘what’ input is particularly odd, including the use of an endocannabinoid as a trigger for synaptic modifications. These cell biological effects make a number of behavioral predictions, certain of which have been confirmed. The essential question of where encoding occurs was addressed by constructing maps of synapses modified during the learning of an environment sufficiently complex that acquisition required transfer from past complexity. These episodic conditions produced synaptic changes at discrete regions of hippocampus largely localized to the output stage. We are including the above collection of findings in models to assess how much of episodic memory phenomenology might reflect the unusual nature of hippocampal networks.