Biomedical subjects

Tonya R Anderson

Publications and source records attributed to Tonya R Anderson.

3 recordsLinked to original sources

PubMed2004

Actin-binding proteins in a postsynaptic preparation: Lasp-1 is a component of central nervous system synapses and dendritic spines.

CNS synapses are complex sites of cell-cell communication. Identification and characterization of the protein components of synapses will lead to a better understanding of the mechanisms of neurotransmission and plasticity. We applied multidimensional protein identification technology (MudPIT) to purified, guanidine-solubilized postsynaptic fractions to identify novel synaptically localized molecules. We identified several actin-associated proteins known to regulate actin polymerization and control cell motility in nonneural cells that have not previously been associated with CNS synaptic function. One of these is lasp-1, an actin-associated LIM and SH3 domain-containing protein. We show that lasp-1 is strongly expressed by CNS neurons and is concentrated at synaptic sites. Overall, the preponderance of actin-associated proteins in postsynaptic density fractions, and specifically those involved in actin reorganization, suggests that there are many modes by which the state of synaptic F-actin polymerization and, hence, synaptic physiology are affected.

Actins↗

PubMed2004

Maturation of glutamatergic and GABAergic synapse composition in hippocampal neurons.

It is commonly accepted that glutamatergic and GABAergic presynaptic terminals form perfectly matched appositions opposite their appropriate receptors and associated binding proteins. However, recent reports indicate that certain synaptic proteins that are commonly used to identify excitatory or inhibitory synapses can be mismatched, particularly during development. In order to construct a more comprehensive scheme of synapse composition during development, we co-immunolabeled for several principle excitatory and inhibitory proteins over the course of synaptogenesis in cultured hippocampal neurons. We find that although the majority of synaptic appositions are composed of matched clusters of pre- and postsynaptic proteins appropriate for a particular neurotransmitter, many are initially mismatched, even in dendrites receiving both glutamatergic and GABAergic innervation. Over time, the fidelity of GABAergic synapse composition increases such that, despite the persistence of some mismatched components at glutamatergic sites, the incidence of mismatch diminishes at both inhibitory and excitatory synapses. Activation of either GABA-A or NMDA receptors promotes fidelity at GABAergic sites, but NMDA receptor activation promotes mismatching among glutamatergic synapses. Thus, apposition of pre- and postsynaptic elements can occur independent of neurotransmitter specificity and synaptic activity modifies these associations. Our findings support the idea that synapse maturation occurs in several distinct stages, and that these stages are regulated by a combination of activity-dependent and -independent factors.

Animals↗

PubMed2002

Differential Pax6 promoter activity and transcript expression during forebrain development.

Three different Pax6 promoters -- P0, P1, and P alpha -- show differential activity in the developing eye and spinal cord. To examine promoter usage during forebrain development, we performed in situ hybridization and reverse transcription-polymerase chain reaction to detect transcripts initiated from each promoter. Promoter-specific transcripts are expressed within subdomains of total Pax6 expression, but differ from one another in their spatial localization and expression over time. Additionally, we identified a novel P0-initiated transcript and detected a developmentally regulated antisense transcript.

Alternative Splicing↗