Publications by authors named "Amanda Jacob"

Neurons coordinate their activity to produce an astonishing variety of motor behaviors. Our present understanding of motor control has grown rapidly thanks to new methods for recording and analyzing populations of many individual neurons over time. In contrast, current methods for recording the nervous system's actual motor output - the activation of muscle fibers by motor neurons - typically cannot detect the individual electrical events produced by muscle fibers during natural behaviors and scale poorly across species and muscle groups.

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Neurons coordinate their activity to produce an astonishing variety of motor behaviors. Our present understanding of motor control has grown rapidly thanks to new methods for recording and analyzing populations of many individual neurons over time. In contrast, current methods for recording the nervous system's actual motor output - the activation of muscle fibers by motor neurons - typically cannot detect the individual electrical events produced by muscle fibers during natural behaviors and scale poorly across species and muscle groups.

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Songbirds and humans share the ability to adaptively modify their vocalizations based on sensory feedback. Prior studies have focused primarily on the role that auditory feedback plays in shaping vocal output throughout life. In contrast, it is unclear how non-auditory information drives vocal plasticity.

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High signal-to-noise ratio (SNR) electromyography (EMG) recordings are essential for identifying and analyzing single motor unit activity. While high-density electrodes allow for greater spatial resolution, the smaller electrode area translates to a higher impedance and lower SNR. In this study, we developed an implantable and flexible 3D microelectrode array (MEA) with low impedance that enables high-quality EMG recording.

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ADAP1/Centaurin-α1 (CentA1) functions as an Arf6 GTPase-activating protein highly enriched in the brain. Previous studies demonstrated the involvement of CentA1 in brain function as a regulator of dendritic differentiation and a potential mediator of Alzheimer's disease (AD) pathogenesis. To better understand the neurobiological functions of CentA1 signaling in the brain, we developed knock-out (KO) mice.

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Dopamine is hypothesized to convey error information in reinforcement learning tasks with explicit appetitive or aversive cues. However, during motor skill learning feedback signals arise from an animal's evaluation of sensory feedback resulting from its own behavior, rather than any external reward or punishment. It has previously been shown that intact dopaminergic signaling from the ventral tegmental area/substantia nigra pars compacta (VTA/SNc) complex is necessary for vocal learning when songbirds modify their vocalizations to avoid hearing distorted auditory feedback (playbacks of white noise).

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Article Synopsis
  • Functional circuits in the visual cortex rely on the interplay between excitatory and inhibitory neurons, with research in mice revealing a "local non-specific pooling principle" for inhibitory connectivity.
  • New findings in ferret visual cortex indicate that inhibitory neurons respond selectively to oriented stimuli, contradicting the idea of untuned inhibitory neuron inputs based on random pooling.
  • The study suggests that the functioning of excitatory-inhibitory interactions may differ in species with a columnar organization, like ferrets, and implies the non-specific pooling principle may not apply broadly to non-murine species.
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A fundamental impediment to understanding the brain is the availability of inexpensive and robust methods for targeting and manipulating specific neuronal populations. The need to overcome this barrier is pressing because there are considerable anatomical, physiological, cognitive and behavioral differences between mice and higher mammalian species in which it is difficult to specifically target and manipulate genetically defined functional cell types. In particular, it is unclear the degree to which insights from mouse models can shed light on the neural mechanisms that mediate cognitive functions in higher species, including humans.

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AMPA receptors are the principal mediators of excitatory synaptic transmission in the mammalian central nervous system. The subunit composition of these tetrameric receptors helps to define their functional properties, and may also influence the synaptic trafficking implicated in long-term synaptic plasticity. However, the organization of AMPAR subunits within the synapse remains unclear.

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Sustained activity-dependent synaptic modifications require protein synthesis. Although proteins can be synthesized locally in dendrites, long-term changes also require nuclear signaling. Amyloid-beta protein precursor intracellular domain-associated protein-1 (AIDA-1), an abundant component of the biochemical postsynaptic density fraction, contains a nuclear localization sequence, making it a plausible candidate for synapse-to-nucleus signaling.

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We have used site-directed mutagenesis of amino acids located within the S1 and S2 ligand binding domains of the NR2A N-methyl-D-aspartate (NMDA) receptor subunit to explore the nature of ligand binding. Wild-type or mutated NR1/NR2A NMDA receptors were expressed in Xenopus laevis oocytes and studied using two electrode voltage clamp. We investigated the effects of mutations in the S1 and S2 regions on the potencies of the agonists L-glutamate, L-aspartate, (R,S)-tetrazol-5yl-glycine, and NMDA.

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