Shelley Halpain

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Neuronal degeneration and cell death can result from excessive activation of receptors for the excitatory neurotransmitter glutamate; however, the very earliest changes in cytoskeletal organization have not been well documented. We have used an in vitro model system to examine the early consequences of intense glutamate receptor activation on dendritic(More)
Microtubule-associated proteins (MAPs) of the MAP2/Tau family include the vertebrate proteins MAP2, MAP4, and Tau and homologs in other animals. All three vertebrate members of the family have alternative splice forms; all isoforms share a conserved carboxy-terminal domain containing microtubule-binding repeats, and an amino-terminal projection domain of(More)
The role of L-type Ca2+ channels in the induction of synaptic plasticity in hippocampal slices of aged (22-24 months) and young adult (4-6 months) male Fischer 344 rats was investigated. Prolonged 1 Hz stimulation (900 pulses) of Schaffer collaterals, which normally depresses CA3/CA1 synaptic strength in aged rat slices, failed to induce long-term(More)
The hypothesis that dynamic actin filaments participate in specific aspects of synaptic plasticity was investigated at the Schaffer-collateral-CA1 pyramidal cell synapse of mouse hippocampus. Low concentrations (0.01-1 microM) of compounds that inhibit actin filament assembly were bath applied to hippocampal slices during extracellular recording of field(More)
Neuregulin-1 (NRG1) and its ErbB2/B4 receptors are encoded by candidate susceptibility genes for schizophrenia, yet the essential functions of NRG1 signaling in the CNS are still unclear. Using CRE/LOX technology, we have inactivated ErbB2/B4-mediated NRG1 signaling specifically in the CNS. In contrast to expectations, cell layers in the cerebral cortex,(More)
During neurite initiation microtubules align to form a tight bundle and actin filaments reorganize to produce a growth cone. The mechanisms that underlie these highly coordinated cytoskeletal rearrangements are not yet fully understood. Recently, various levels of coordination between the actin- and microtubule-based cytoskeletons have been observed during(More)
In the caudate-putamen the glutamatergic cortical input and the dopaminergic nigrostriatal input have opposite effects on the firing rate of striatal neurons. Although little is known of the biochemical mechanisms underlying this antagonism, one action of dopamine is to stimulate the cyclic AMP-dependent phosphorylation of DARPP-32 (dopamine and(More)
Dendritic spines are small protrusions from neuronal dendrites that form the postsynaptic component of most excitatory synapses in the brain. They play critical roles in synaptic transmission and plasticity. Recent advances in imaging and molecular technologies reveal that spines are complex, dynamic structures that contain a dense array of cytoskeletal,(More)
The current research examined the regulation of synaptic strength by protein phosphorylation during aging. Bath application of the protein phosphatase 1 and 2A (PP1 and PP2A) inhibitor calyculin A (1 microM) enhanced CA3-CA1 synaptic strength in hippocampal slices from aged male (20-24 mo) but not from young adult male (4-6 mo) Fischer 344 rats. Similarly,(More)
MAP1-family proteins are classical microtubule-associated proteins (MAPs) that bind along the microtubule lattice. The founding members, MAP1A and MAP1B, are predominantly expressed in neurons, where they are thought to be important in the formation and development of axons and dendrites. Mammalian genomes usually contain three family members, MAP1A, MAP1B(More)