Mark McCarren

Learn More
We have used the rat hippocampal slice preparation as a model system for studying the epileptogenic consequences of a reduction in neuronal Na+-K+ pump activity. The cardiac glycosides (CGs) strophanthidin and dihydroouabain were used to inhibit the pump. These drugs had readily reversible effects, provided they were not applied for longer than 15-20 min.(More)
We have used intracellular recording techniques to study the use-dependence of evoked inhibitory postsynaptic potentials (IPSPs) in rat CA1 hippocampal pyramidal cells. We determined reversal potentials and conductance changes associated with IPSPs and responses to directly applied gamma-aminobutyric acid (GABA). The IPSP depression could be seen after a(More)
In electrophysiological studies using the rat hippocampal slice preparation, cholinergic agonists and phorbol 12,13-diacetate, a stimulator of protein kinase C, block the inhibitory actions of baclofen, a gamma-aminobutyric acid B receptor agonist, and adenosine. Relative potencies of cholinergic agonists in stimulating the phosphatidylinositol system, as(More)
Unusual cellular elements have been recorded intracellularly in the CA1 region of the rat hippocampal slice. The elements appear, by all electrophysiological criteria except one, to be glia. However, unlike glia, they can fire action potentials. We suggests that these recordings represent cases of artifactual coupling of two cells by a recording(More)
Intracellular recordings were made from the CA1 stratum pyramidale region of rat hippocampal slices. Papain was applied to the cells via bath perfusion, and its effects on membrane properties, synaptic potentials and responses to pressure application of gamma-aminobutyric acid (GABA) were assessed. Papain did not markedly affect neuronal input resistance,(More)
IP(s)3, a metabolically stable analog of 1,4,5-inositol trisphosphate (IP3), inhibited action potential firing when injected into hippocampal pyramidal cells. This effect was associated with decreased input resistance, a more negative resting potential, outward rectification at depolarized potentials, and an afterhyperpolarization. The response to IP(s)3(More)
To help combat trafficking in human beings for organ removal (THBOR), transplant professionals need to do more than carry out careful, multidisciplinary screening of potential living donors; they also need to communicate and collaborate with law enforcement professionals. This will involve transplant professionals educating investigators and prosecutors(More)
Using intracellular recording techniques in the rat hippocampal slice, we observed that muscarinic agonists produce a transient Ca2+-dependent depolarization that may be related to the phosphatidylinositol cycle. First, it was more readily produced by muscarinic group A agonists, which strongly enhance the breakdown of phosphatidylinositol-4,5-bisphosphate(More)
Male rats were exposed to lead from parturition through weaning. When subjected to electrical hippocampal kindling as adults, although there were no alterations in the kindling rates, lead-treated animals were found to differ from controls in several other respects. In contrast to controls, lead-treated animals did not show an increase in afterdischarge(More)
Male Sprague-Dawley rats were exposed to lead from parturition to weaning via the dams' milk. Dams were provided with drinking water containing 1.0 (LL), 2.5 (ML), or 5.0 (HL) mg/ml lead acetate or 1.25 (C) mg/ml sodium acetate. Beginning at 15 weeks of age, characteristics of the electrically elicited hippocampal afterdischarge (AD) and its alteration by(More)
  • 1