Hays, Seth
Permanent URI for this collectionhttps://hdl.handle.net/10735.1/5103
Dr. Seth Hays is an Associate Professor in the Jonsson School's Department of Bioengineering. He is also the Principle Investigator of the Targeted Neuroplasticity Lab. His research is focused on enhancing neuroplasticity in order to treat neurological disease and also to investigate the cellular and molecular mechanisms that underlie any recovery from it. In 2015 he received the prestigious American Heart Association Robert G. Siekert New Investigator for Stroke Award.
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Browsing Hays, Seth by Author "Buell, Elizabeth P."
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Item Cortical Map Plasticity as a Function of Vagus Nerve Stimulation Rate(Elsevier Inc.) Buell, Elizabeth P.; Loerwald, Kristofer W.; Engineer, Crystal T.; Borland, Michael S .; Buell, John M.; Kelly, C. A.; Khan, I. I.; Hays, Seth A.; Kilgard, Michael P.; Buell, Elizabeth P.; Loerwald, Kristofer W.; Engineer, Crystal T.; Borland, Michael S .; Buell, John M.; Kelly, C. A.; Khan, I. I.; Hays, Seth A.; Kilgard, Michael P.Background: Repeatedly pairing a brief train of vagus nerve stimulation (VNS) with an external event can reorganize the sensory or motor cortex. A 30 Hz train of sixteen VNS pulses paired with a tone significantly increases the number of neurons in primary auditory cortex (A1) that respond to tones near the paired tone frequency. The effective range of VNS pulse rates for driving cortical map plasticity has not been defined. Objective/Hypothesis: This project investigated the effects of VNS rate on cortical plasticity. We expected that VNS pulse rate would affect the degree of plasticity caused by VNS-tone pairing. Methods: Rats received sixteen pulses of VNS delivered at a low (7.5 Hz), moderate (30 Hz), or high (120 Hz) rate paired with 9 kHz tones 300 times per day over a 20 day period. Results: More A1 neurons responded to the paired tone frequency in rats from the moderate rate VNS group compared to naïve controls. The response strength was also increased in these rats. In contrast, rats that received high or low rate VNS failed to exhibit a significant increase in the number of neurons tuned to sounds near 9 kHz. Conclusion: Our results demonstrate that the degree of cortical plasticity caused by VNS-tone pairing is an inverted-U function of VNS pulse rate. The apparent high temporal precision of VNS-tone pairing helps identify optimal VNS parameters to achieve the beneficial effects from restoration of sensory or motor function.Item Vagus Nerve Stimulation Rate and Duration Determine Whether Sensory Pairing Produces Neural Plasticity(Elsevier Ltd) Buell, Elizabeth P.; Borland, Michael S.; Loerwald, Kristopher W.; Chandler, Collin; Hays, Seth A.; Engineer, Crystal T.; Kilgard, Michael P.; 0000-0003-4225-241X (Hays, SA); 13146094343400332984 (Hays, SA); Buell, Elizabeth P.; Borland, Michael S.; Loerwald, Kristopher W.; Chandler, Collin; Hays, Seth A.; Engineer, Crystal T.; Kilgard, Michael P.Repeatedly pairing a brief train of vagus nerve stimulation (VNS) with an auditory stimulus drives reorganization of primary auditory cortex (A1), and the magnitude of this VNS-dependent plasticity is dependent on the stimulation parameters, including intensity and pulse rate. However, there is currently little data to guide the selection of VNS train durations, an easily adjusted parameter that could influence the effect of VNS-based therapies. Here, we tested the effect of varying the duration of the VNS train on the extent of VNS-dependent cortical plasticity. Rats were exposed to a 9 kHz tone 300 times per day for 20 days. Coincident with tone presentation, groups received trains of 4, 16, or 64 pulses of VNS delivered at 30 Hz, corresponding to train durations of 0.125 s, 0.5 s, and 2.0 s, respectively. High-density microelectrode mapping of A1 revealed that 0.5 s duration VNS trains significantly increased the number of neurons in A1 that responded to tones near the paired tone frequency. Trains lasting 0.125 or 2.0 s failed to alter A1 responses, indicating that both shorter and longer stimulation durations are less effective at enhancing plasticity. A second set of experiments evaluating the effect of delivering 4 or 64 pulses in a fixed 0.5 s VNS train duration paired with tone presentation reveal that both slower and faster stimulation rates are less effective at enhancing plasticity. We incorporated these results with previous findings describing the effect of stimulation parameters on VNS-dependent plasticity and activation of neuromodulatory networks to generate a model of synaptic activation by VNS. ©2019 Elsevier Ltd