Publications by authors named "D J Speca"

Activity-dependent alterations in the levels of synaptic AMPA receptors (AMPARs) within the postsynaptic density (PSD) is thought to represent a cellular mechanism for learning and memory. Palmitoylation regulates localization and function of many synaptic proteins including AMPA-Rs, auxiliary factors and synaptic scaffolds in an activity-dependent manner. We identified the synapse differentiation induced gene (SynDIG) family of four genes (SynDIG1-4) encoding brain-specific transmembrane proteins that associate with AMPARs and regulate synapse strength.

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Altering AMPA receptor (AMPAR) content at synapses is a key mechanism underlying the regulation of synaptic strength during learning and memory. Previous work demonstrated that SynDIG1 (synapse differentiation-induced gene 1) encodes a transmembrane AMPAR-associated protein that regulates excitatory synapse strength and number. Here we show that the related protein SynDIG4 (also known as Prrt1) modifies AMPAR gating properties in a subunit-dependent manner.

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The identification of novel genes underlying complex mouse behavioral traits remains an important step in understanding normal brain function and its dysfunction in mental health disorders. To identify dominant mutations that influence locomotor activity, we performed a mouse N-ethyl-N-nitrosourea (ENU) forward mutagenesis screen and mapped several loci as quantitative traits. Here we describe the fine-mapping and positional cloning of a hyperactivity locus mapped to the medial portion of mouse chromosome four.

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Modification of the strength of excitatory synaptic connections is a fundamental mechanism by which neural circuits are refined during development and learning. Synapse Differentiation Induced Gene 1 (SynDIG1) has been shown to play a key role in regulating synaptic strength . Here, we investigated the role of SynDIG1 in mice with a disruption of the gene rather than use an alternate loxP-flanked conditional mutant that we find retains a partial protein product.

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The epileptic encephalopathies are a group of highly heterogeneous genetic disorders. The majority of disease-causing mutations alter genes encoding voltage-gated ion channels, neurotransmitter receptors, or synaptic proteins. We have identified a novel de novo pathogenic K+ channel variant in an idiopathic epileptic encephalopathy family.

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