Sharyn Marks

Learn More
Salamanders are infrequently mentioned in analyses of tetrapod limb formation, as their development varies considerably from that of amniotes. However, urodeles provide an opportunity to study how limb ontogeny varies with major differences in life history. Here we assess limb development in Desmognathus aeneus, a direct-developing salamander, and compare(More)
Dextromethorphan and dextrorphan, which reduce excitatory amino acid-induced neurotoxicity, decreased K+ depolarization-evoked 45Ca2+ uptake into brain synaptosomes and cultured neural (PC12) cells. Half-maximal inhibition of synaptosomal 45Ca2+ uptake occurred with 48 microM dextromethorphan or 200 microM dextrorphan, which are similar to concentrations(More)
Treatment with 200 mM ethanol for 6 days increased binding of the Ca2+ channel antagonist, (+)-[3H]PN 200-110, to intact PC12 cells in culture. Enhancement of binding by ethanol was due to an increase in binding site number without appreciable change in binding affinity. Long-term exposure to Ca2+ channel antagonist drugs (nifedipine, verapamil, or(More)
Polyvalent cations that block excitatory responses to N-methyl-D-aspartate inhibited the binding of [3H]MK-801 to putative N-methyl-D-aspartate receptor-gated channels in brain membranes. The order of potency was Zn2+ greater than La3+ = Cd2+ greater than Mn2+ greater than Co2+ greater than Ni2+ = Mg2+. These findings support the existence of interacting(More)
Exposure to ethanol for days to weeks enhances the expression of voltage-dependent Ca2+ channels in the brains of experimental animals and in cultured neural cell lines. To determine if similar changes occur in the brains of alcoholic patients, we measured the binding of (+)-[3H]PN 200-110 to cerebral cortex samples obtained at autopsy from alcoholic and(More)
Drugs that block voltage-gated Ca2+ channels or N-methyl-D-aspartate receptor-gated channels have been shown to reduce experimental hypoxic-ischemic neuronal injury. To determine if any such compounds interact with both types of channels, and might therefore be prototypes for new anti-ischemic drugs with dual therapeutic actions, we compared the affinities(More)
The density of calcium channel antagonist receptors labeled by (+)-[3H]PN 200-110 was reduced by 75% in striata from patients with Huntington's disease, but unchanged in patients with Parkinson's disease, compared with control subjects. These receptors are therefore likely to be localized to neurons with cell bodies in striatum, rather than nigrostriatal(More)
  • 1