COVID-19 Updates

Visit UC San Diego's Coronavirus portal for the latest information for the campus community.

Jill Leutgeb, PhD

Jill Leutgeb, PhD

Assistant Professor of Biology, UC San Diego

Contact Information

Neurobiology Section, Division of Biological Sciences
9500 Gilman Dr. 0357
La Jolla, CA 92093-0357
Office: 858-246-0825
Fax: 858-534-7309

Neural network mechanisms for memory formation

Episodic memories are unique in that they contain information about what happened when and where. Although these memories are formed rapidly and occur only once they can be distinguished from many similar memories even though only few of the features of which they are composed are distinct. The hippocampus is essential for the encoding of episodic memories and has been modeled to perform this function by mediating the convergence of multiple representations of upstream cortical areas into a single, unique memory trace. Our lab is interested in understanding how the hippocampus performs this operation, as well as how the neuronal networks of this brain region combine information about what happened when and where to establish a lasting memory. The main goal of our research is to describe the neural basis of memory formation and retrieval at the systems level, and to determine how the various subregions of the medial temporal lobe, including the hippocampus, contribute to memory processing. We are interested in what type of information the distinct populations of medial temporal lobe neurons convey and how coordinated neuronal activity and synaptic plasticity in these networks contribute to the distinct computations essential for the encoding of episodic memory. Our lab is particularly interested in understanding the network computations of neuronal populations in the first processing stages of the hippocampus, namely the CA3 and dentate gyrus. The anatomically distinct arrangement of this brain region has inspired many computational models that have hypothesized its distinct role in memory formation. While behavioral studies have supported many of these predictions, very little is known about how the CA3-dentate neural network perform these functions, and what the various cell populations within the network contribute to the encoding necessary for memory formation. To address these questions we record simultaneously from large groups of neurons (up to 100) in anatomically and functionally related circuits in the mammalian brain during learning. Our lab combines high-density electrophysiology, behavioral testing, theoretical modeling, and pharmacological and molecular manipulations as a multidisciplinary approach to understanding the neural basis of cognition. Understanding the contribution of the various cell populations within the CA3-dentate network to memory formation will have considerable importance for systems neuroscience and also for translational research since the dentate gyrus is among the first structures in the brain to show decreased neuronal activity in Alzheimer’s disease. In addition, diverse changes in the dentate network and the activity patterns of its neurons have also been linked to the onset of temporal lobe epilepsy, and depression.

Mankin EA, Diehl GW, Sparks FT, Leutgeb S, Leutgeb JK (2015) Hippocampal CA2 activity patterns change over time to a larger extent than between spatial contexts. Neuron, 85:190-201.

Sasaki T, Leutgeb S, Leutgeb JK (2015) Spatial and memory circuits in the medial entorhinal cortex. Curr Opin Neurobiol, 32: 16-23.

Schlesiger MI, Cannova CC, Boublil B, Hales JB, Mankin EA, Brandon MP, Leutgeb JK, Leibold C, Leutgeb S (2015) The medial entorhinal cortex is necessary for the temporal organization of hippocampal neuronal activity. Nat Neurosci 18:1123-32.

Hales JB, Schlesiger MI, Leutgeb JK, Squire LR, Leutgeb S, Clark RE (2014) Medial entorhinal cortex lesions only partially disrupt hippocampal place cells and hippocampus-dependent place memory. Cell Rep, 9:893-901.

Brandon MP, Koenig J, Leutgeb JK, Leutgeb S (2014) New and distinct hippocampal place codes are generated in a new environment during septal inactivation. Neuron, 82:789-796.

Lu L*, Leutgeb JK*, Tsao A, Henriksen EJ, Leutgeb S, Barnes CA, Witter MP, Moser M-B, Moser EI (2013) Impaired hippocampal rate coding after lesions of the lateral entorhinal cortex. Nat Neurosci. 16:1085-1093. *Equal co-first authors

Piatti VC, Ewell LA, Leutgeb JK (2013) Neurogenesis in the dentate gyrus: carrying the message or dictating the tone. Front Neurosci 7:50.

Schlesiger MI, Cressey JC, Boublil B, Koenig J, Melvin NR, Leutgeb JK, Leutgeb S (2013) Hippocampal activation during the recall of remote spatial memories in radial maze tasks. Neurobiol Learn Mem, 106:324-333.

Mankin EA, Sparks FT, Slayyeh B, Sutherland RJ, Leutgeb S, Leutgeb JK (2012) A neuronal code for extended time in the hippocampus. PNAS, 109:19462-19467.

Koenig J, Linder AN, Leutgeb JK, Leutgeb S (2011) The spatial periodicity of grid cells is not sustained during reduced theta oscillations. Science, 332:592-595.

Leutgeb JK, Leutgeb S, Moser M-B, Moser EI (2007) Pattern separation in dentate gyrus and CA3 of the hippocampus. Science, 315:961-966.

Leutgeb JK, Moser EI (2007) Enigmas of the dentate gyrus. Neuron, 55:176-178.

Leutgeb S, Leutgeb JK (2007) Pattern separation, pattern completion and new neuronal codes within a continuous CA3 map. Learn Mem 14:745-757.

Leutgeb S, Leutgeb JK, Moser EI, Moser M-B (2006) Fast rate coding in hippocampal CA3 cell assemblies. Hippocampus 16:765-774.

Leutgeb JK, Leutgeb S, Treves A, Meyer R, Barnes CA, McNaughton BL, Moser M-B, Moser EI (2005) Progressive transformation of hippocampal neuronal representations in "morphed" environments. Neuron 48:345-358.

Leutgeb S, Leutgeb JK, Moser M-B, Moser EI (2005) Place cells, spatial maps and the population code for memory. Curr Opin Neurobiol 15:738-746.

Leutgeb S, Leutgeb JK, Barnes CA, Moser EI, McNaughton BL, Moser M-B (2005) Independent codes for spatial and episodic memory in hippocampal neuronal ensembles. Science 309:619-623.

Leutgeb S, Leutgeb JK, Treves A, Moser M-B, Moser EI (2004) Distinct ensemble codes in hippocampal areas CA3 and CA1. Science 305:1295-1298.