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Low-frequency electrical signals like those that compose the local field potential (LFP) can be detected at substantial distances from their point of origin within the brain. It is thus unclear how useful the LFP might be for assessing local function, for example, on the spatial scale of cortical columns. We addressed this problem by comparing speed and(More)
We conducted electrophysiological recording and microstimulation experiments to test the hypothesis that the middle temporal visual area (MT) plays a direct role in perception of the speed of moving visual stimuli. We trained rhesus monkeys on a speed discrimination task in which monkeys chose the faster speed of two moving random dot patterns presented(More)
We analyzed the functional organization of speed tuned neurons in extrastriate visual area MT. We sought to determine whether neurons tuned for particular speeds are clustered spatially and whether such spatial clusters are elongated normal to the cortical surface so as to form speed columns. Our data showed that MT neurons are indeed clustered according to(More)
Accumulation of β-amyloid and hyperphosphorylated tau with synapse damage and memory deterioration are hallmark lesions of Alzheimer disease (AD), but the upstream causative factors are elusive. The advanced glycation endproducts (AGEs) are elevated in AD brains and the AGEs can stimulate β-amyloid production. Whether and how AGEs may cause AD-like tau(More)
BACKGROUND Methamphetamine (MA) use among pregnant women is an increasing problem in the United States. How prenatal MA exposure affects neonatal neurobehavior is unknown. OBJECTIVE To examine the neurobehavioral effects of prenatal MA exposure. DESIGN The Infant Development, Environment and Lifestyle (IDEAL) study screened 13,808 subjects and 1632 were(More)
Oxysterols bind the seven-transmembrane protein Smo (Smo) and potently activate vertebrate Hedgehog (Hh) signaling, a pathway essential in embryonic development, adult stem cell maintenance and cancer. It is unknown, however, whether oxysterols are important for normal vertebrate Hh signaling and whether antagonizing oxysterols can inhibit the Hh pathway.(More)
BACKGROUND AND PURPOSE Hypoxic preconditioning is an endogenous protection against subsequent lethal hypoxia, but the mechanism involved is not understood. Hypoxia is followed by reactive oxygen species (ROS) production and induces hypoxia-inducible factor (HIF) and its downstream factor erythropoietin (Epo), which is associated with neuroprotection. We(More)
Fragile X-associated tremor/ataxia syndrome (FXTAS) is a leading monogenic neurodegenerative disorder affecting premutation carriers of the fragile X (FMR1) gene. To investigate the underlying cellular neuropathology, we produced induced pluripotent stem cell-derived neurons from isogenic subclones of primary fibroblasts of a female premutation carrier,(More)
Specific chromatin marks keep master regulators of differentiation silent yet poised for activation by extracellular signals. We report that nodal TGF-β signals use the poised histone mark H3K9me3 to trigger differentiation of mammalian embryonic stem cells. Nodal receptors induce the formation of companion Smad4-Smad2/3 and TRIM33-Smad2/3 complexes. The(More)
This study explores whether the hydroxyl radical (*OH)-one of the most destructive reactive oxygen species-plays a role in secondary spinal cord injury (SCI). First, we measured the time course of *OH formation in rat spinal tissue after impact SCI by administering salicylate as a trapping agent into the intrathecal space of the cord and measuring the(More)