Katherine Conant, MD

Professor

Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases that can be released and/or activated in a neuronal activity dependent manner. MMP expression and activity can also be dramatically upregulated with injury, including that mediated by infection or hypoxia. Many studies have therefore focused on their role in brain pathology. Physiological release of MMPs is, however, critical to adaptive processes including learning and memory.

Our work is focused on the mechanisms by which MMPs influence neuronal and synaptic structure and function. We are particularly interested in their ability to cleave specific synaptic adhesion molecules and their ability to influence neuronal population activities important to mood and memory through modulation of the perineuronal net.

Perineuronal nets (PNNs) predominantly surround fast spiking GABAergic interneurons in brain regions including the cortex and hippocampus. Through varied mechanisms, including their ability to reduce membrane capacitance, these nets facilitate inhibitory neuronal transmission. PNNs may be pathologically increased or decreased in specific disease states including major depressive disorder. 

PNN and MMP mediated effects on neuronal structure and function are tested in varied models, including those related to disease. Present PhD students include Matthew Amontree, Katie Hummel, Katelyn Dial and Pauline Wonnenberg. Former PhD students include Doctors Megan Allen, Lorenzo Bozzelli, Seham Alaiyed, Griffin Greco, Ismary Blanco, and Karli Gilbert.