Input/Output Relationships for the Primary Hippocampal Circuit.

The hippocampus is the most studied brain region, but little is known about signal throughput-the simplest, yet most essential of circuit operations-across its multiple stages from perforant path input to CA1 output. Using hippocampal slices derived from male mice, we have found that single-pulse lateral perforant path (LPP) stimulation produces a two-part CA1 response generated by LPP projections to CA3 ("direct path") and the dentate gyrus ("indirect path"). The latter, indirect path was far more potent in driving CA1 but did so only after a lengthy delay.

Pre- versus Post-synaptic Forms of LTP in Two Branches of the Same Hippocampal Afferent.

There has been considerable controversy about pre- versus postsynaptic expression of memory-related long-term potentiation (LTP), with corresponding disputes about underlying mechanisms. We report here an instance in male mice, in which both types of potentiation are expressed but in separate branches of the same hippocampal afferent. Induction of LTP in the dentate gyrus (DG) branch of the lateral perforant path (LPP) reduces paired-pulse facilitation, is blocked by antagonism of cannabinoid receptor type 1, and is not affected by suppression of postsynaptic actin polymerization.

Novel types of frequency filtering in the lateral perforant path projections to dentate gyrus.

Despite its evident importance to learning theory and models, the manner in which the lateral perforant path (LPP) transforms signals from entorhinal cortex to hippocampus is not well understood. The present studies measured synaptic responses in the dentate gyrus (DG) of adult mouse hippocampal slices during different patterns of LPP stimulation. Theta (5 Hz) stimulation produced a modest within-train facilitation that was markedly enhanced at the level of DG output.

Role of oxidative stress in inactivation of Escherichia coli BW25113 by nanoscale zero-valent iron.

An Escherichia coli BW25113 wildtype strain and mutant strains lacking genes that protect against oxidative stress were examined at different growth phases for susceptibility to zero-valent iron (nZVI). Viability of cells was determined by the plate count method. All mutant strains were more susceptible than the wild type strain to nZVI; however, susceptibility differed among the mutant strains.

Impact of nanoscale zero valent iron on bacteria is growth phase dependent.

The toxic effect of nanoscale zero valent iron (nZVI) particles on bacteria from different growth phases was studied. Four bacterial strains namely Escherichia coli strains JM109 and BW25113, and Pseudomonas putida strains KT2440 and F1 were experimented. The growth curves of these strains were determined.