Faculty Bibliography

Beta oscillations (13.5-25 Hz) over the sensorimotor areas are characterized by a power decrease during movement execution (event-related desynchronization, ERD) and a sharp rebound after the movement end (event-related synchronization, ERS). In previous studies, we demonstrated that movement-related beta modulation depth (peak ERS-ERD) during reaching increases within 1-h practice. This increase may represent plasticity processes within the sensorimotor network. If so, beta modulation during a reaching test should be affected by previous learning activity that engages the sensorimotor system but not by learning involving other systems. We thus recorded high-density EEG activity in a group of healthy subjects performing three 45-min blocks of motor adaptation task to a visually rotated display (ROT) and in another performing three blocks of visual sequence-learning (VSEQ). Each block of either ROT or VSEQ was followed by a simple reaching test (mov) without rotation. We found that beta modulation depth increased with practice across mov tests. However, such an increase was greater in the group performing ROT over both the left and frontal areas previously involved in ROT. Importantly, beta modulation values returned to baseline values after a 90-min of either nap or quiet wake. These results show that previous practice leaves a trace in movement-related beta modulation and therefore such increases are cumulative. Furthermore, as sleep is not necessary to bring beta modulation values to baseline, they could reflect local increases of neuronal activity and decrease of energy and supplies.

BACKGROUND:Early identification of vasospasm prior to symptom onset would allow prevention of delayed cerebral ischemia (DCI) in aneurysmal subarachnoid hemorrhage (aSAH). Dynamic cerebral autoregulation (DCA) is a noninvasive means of assessing cerebral blood flow regulation by determining independence of low-frequency temporal oscillations of systemic blood pressure (BP) and cerebral blood flow velocities (CBFV). METHODS:Eight SAH patients underwent prospectively a median of 7 DCA assessments consisting of continuous measurements of BCFV and BP. Transfer function analysis was applied to calculate average phase shift (PS) in low (0.07-0.2 Hz) frequency range for each hemisphere as continuous measure of DCA. Lower PS indicated poorer regulatory response. DCI was defined as a 2-point decrease in Glasgow Coma Score and/or infarction on CT. RESULTS:Three subjects developed symptomatic vasospasm with median time-to-DCI of 9 days. DCI was significantly associated with lower PS over the entire recording period (Wald = 4.28; p = 0.039). Additionally, there was a significant change in PS over different recording periods after adjusting for DCI (Wald = 15.66; p = 0.001); particularly, a significantly lower mean PS day 3-5 after bleed (14.22 vs 27.51; p = 0.05). CONCLUSIONS:DCA might be useful for early detection of symptomatic vasospasm. A larger cohort study of SAH patients is currently underway.

Background: The association between early changes in albuminuria and kidney and CV events is primarily based on trials of renin-angiotensin system blockade. It is unclear whether this association is similar with sodium-glucose cotransporter 2 inhibitors.
Method(s): In this post-hoc analysis of the CREDENCE trial in patients with type 2 diabetes and chronic kidney disease, we assessed the effect of CANA versus placebo on albuminuria at week 26, and the association of early changes in urinary albumin:creatinine ratio (UACR) for the first 26 weeks with kidney and CV outcomes using multivariable Cox regression. Kidney and CV outcomes were defined as (1) endstage kidney disease, doubling of serum creatinine or death due to kidney disease, (2) major adverse cardiovascular events (MACE) and (3) hospitalization for heart failure (HHF) or CV death.
Result(s): This analysis included 3836 participants (87.2%) with complete data for early changes in UACR. CANA lowered UACR by 31% (95%CI 27-36%) at week 26 and increased the likelihood of achieving a 30% UACR reduction (OR 2.69, 95%CI 2.35- 3.07). We observed log-linear associations of early changes in UACR during 26 weeks with kidney and CV outcomes (all p trend <0.001; Table). Each 30% UACR reduction was independently associated with a lower hazard for clinical outcomes, overall and in each treatment arm (all p <0.001).
Conclusion(s): In people with type 2 diabetes and CKD, canagliflozin results in early and sustained reductions in albuminuria, which was independently associated with longterm kidney and cardiovascular outcomes. (Table Presented)

High-fidelity measurements of neural activity can enable advancements in our understanding of the neural basis of complex behaviors such as speech, audition, and language, and are critical for developing neural prostheses that address impairments to these abilities due to disease or injury. We develop a novel high resolution, thin-film micro-electrocorticography (micro-ECoG) array that enables high-fidelity surface measurements of neural activity from songbirds, a well-established animal model for studying speech behavior. With this device, we provide the first demonstration of sensory-evoked modulation of surface-recorded single unit responses. We establish that single unit activity is consistently sensed from micro-ECoG electrodes over the surface of sensorimotor nucleus HVC (used as a proper name) in anesthetized European starlings, and validate responses with correlated firing in single units recorded simultaneously at surface and depth. The results establish a platform for high-fidelity recording from the surface of subcortical structures that will accelerate neurophysiological studies, and development of novel electrode arrays and neural prostheses.