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Bice, A. R.

Publications and source records attributed to Bice, A. R..

3 recordsLinked to original sources

Sulfonylureas target the neurovascular response to decrease Alzheimer's pathology

Hyperexcitability is a defining feature of Alzheimers disease (AD), where aberrant neuronal activity is both a cause and consequence of AD. Therefore, identifying novel targets that modulate cellular excitability is an important strategy for treating AD. ATP-sensitive potassium (KATP) channels are metabolic sensors that modulate cellular excitability. Sulfonylureas are KATP channel antagonists traditionally used to combat hyperglycemia in diabetic patients by inhibiting pancreatic KATP channels, thereby stimulating insulin release. However, KATP channels are not limited to the pancreas and systemic modulation of KATP channels has pleotropic physiological effects, including profound effects on vascular function. Here, we demonstrate that human AD patients have higher cortical expression of vascular KATP channels, important modulators of vasoreactivity. We demonstrate that peripheral treatment with the sulfonylurea and KATP channel inhibitor, glyburide, reduced the aggregation and activity-dependent production of amyloid-beta (A{beta}), a hallmark of AD, in mice. Since glyburide does not readily cross the blood brain barrier, our data suggests that glyburide targets vascular KATP channel activity to reduce arterial stiffness, improve vasoreactivity, and normalize pericyte-endothelial cell morphology, offering a novel therapeutic target for AD. Graphical abstractTargeting vascular KATP channel activity for the treatment of Alzheimers disease pathology. O_FIG_DISPLAY_L [Figure 1] M_FIG_DISPLAY C_FIG_DISPLAY

neuroscience

Homotopic contralesional excitation suppresses spontaneous circuit repair and global network reconnections following ischemic stroke

Understanding circuit-level changes that affect the brains capacity for plasticity will inform the design of targeted interventions for treating stroke recovery. We combine optogenetic photostimulation with optical neuroimaging to examine how contralesional excitatory activity affects cortical remodeling after stroke in mice. Following photothrombosis of left primary somatosensory forepaw (S1FP) cortex, mice received chronic excitation of right S1FP, a maneuver mimicking the use of the unaffected limb during recovery. Contralesional excitation suppressed perilesional S1FP remapping and was associated with abnormal patterns of evoked activity in the unaffected limb. Contralesional stimulation prevented the restoration of resting-state functional connectivity (RSFC) within the S1FP network, RSFC in several networks functionally-distinct from somatomotor regions, and resulted in persistent limb-use asymmetry. In stimulated mice, perilesional tissue exhibited suppressed transcriptional changes in several genes important for recovery. These results suggest that contralesional excitation impedes local and global circuit reconnection through suppression of several neuroplasticity-related genes after stroke.

neuroscience

Functional connectivity of the developing mouse cortex

Cross-sectional studies have established a variety of structural, synaptic and cell physiological changes corresponding to key critical periods in cortical development. However, the emergence of functional connectivity (FC) in development has not been fully characterized, and hemodynamic-based measures are vulnerable to any neurovascular coupling changes occurring in parallel. We therefore used optical fluorescence imaging to trace longitudinal calcium FC in the awake, resting-state mouse cortex in the same mice at 5 developmental time points beginning at postnatal day 15 (P15) and ending in early adulthood (P60), resulting in over 500 imaging epochs with both calcium and hemodynamics available as a resource for the field. Proof-of-principle analyses revealed that calcium FC displayed coherent functional maps as early as P15, and FC significantly varied in connections between many regions across development, with the developmental trajectorys shape specific to the functional region. This longitudinal developmental calcium FC dataset provides an essential resource for further algorithm development and studies of healthy development and neurodevelopmental disorders.

neuroscience