Professor, Kavli Institute for Systems Neuroscience
Ph.D. New York University Medical Center
B.A. New College
Research Interests: Cellular and molecular basis of memory.
Overview: What changes in your brain when you learn something? Lesion studies have determined that a highly conserved structure called the hippocampus is required for memory acquisition in mammals, including humans. My laboratory is interested in how neurons in the hippocampus and related brain areas reflect experience. We use two distinct but complementary approaches to this goal: 1) recording neurons from awake, behaving rodents; and 2) generating genetically-modified mice capable of expressing transgenes in particular neuronal cell types relevant to learning and memory. Combining the former with the latter enables the neural analog of the approach used by engineers to investigate electrical circuits: basically, one records from one circuit element (i.e. neuronal cell type) while manipulating the activity of others. In this way we can explore the transformation of information through the circuitry underlying learning and memory.
A Novel Mechanism for the Grid-to-Place Cell Transformation Revealed by Transgenic Depolarization of Medial Entorhinal Cortex Layer II.
Neuron. 2017 Mar 22;93(6):1480-1492.e6
Authors: Kanter BR, Lykken CM, Avesar D, Weible A, Dickinson J, Dunn B, Borgesius NZ, Roudi Y, Kentros CG
The spatial receptive fields of neurons in medial entorhinal cortex layer II (MECII) and in the hippocampus suggest general and environment-specific maps of space, respectively. However, the relationship between these receptive fields remains unclear. We reversibly manipulated the activity of MECII neurons via chemogenetic receptors and compared the changes in downstream hippocampal place cells to those of neurons in MEC. Depolarization of MECII impaired spatial memory and elicited drastic changes in CA1 place cells in a familiar environment, similar to those seen during remapping between distinct environments, while hyperpolarization did not. In contrast, both manipulations altered the firing rate of MEC neurons without changing their firing locations. Interestingly, only depolarization caused significant changes in the relative firing rates of individual grid fields, reconfiguring the spatial input from MEC. This suggests a novel mechanism of hippocampal remapping whereby rate changes in MEC neurons lead to locational changes of hippocampal place fields.
PMID: 28334610 [PubMed - in process]