Reactive oxygen species, including superoxide, generally are considered neurotoxic molecules whose effects can be alleviated by antioxidants. Different from this view, we show that scavenging of superoxide with an antioxidant enzyme is associated with deficits in hippocampal long-term potentiation (LTP), a putative neural substrate of memory, and hippocampal-mediated memory function. Using tran...

INTRODUCTION Different animal models for Alzheimer disease (AD) have been designed to support the hypothesis that the neurodegeneration (loss of neurons and synapses with reactive gliosis) associated with Aβ and tau deposition in these models is similar to that in the human brain. These alterations produce functional changes beginning with decreased ability to carry out daily and social life ac...

Although interneurons in area CA1 of the hippocampus are less vulnerable to cerebral ischemia than CA1 pyramidal cells, it is not clear whether their relatively intact cellular morphology implies preservation of normal function. As maintenance of cellular excitability and firing properties is essential for interneurons to regulate neural networks, we investigated these aspects of interneuronal ...

Mechanisms for electroacupuncture (EA) in disease treatments are still enigmatic. Here, we studied whether hippocampus was involved in the protection of EA stimulation on myocardial ischemia injury. Acute myocardial ischemia (AMI) model was produced. EA stimulation at heart meridian from Shenmen (HT7) to Tongli (HT5) was applied to rats 3 times a day for continuous three days. Coronary occlusio...

Reactive oxygen species (ROS) modulate neuronal excitability. In the present study we examined the effects of hydrogen peroxide (H(2)O(2)), a well established ROS, on neuronal activity from two neonatal mouse brain regions, i.e., the pre-Bötzinger complex (preBötC) within the ventral respiratory column (VRC) and the CA1 area of the hippocampus. In the preBötC, 2.2 mM H(2)O(2) evoked a transient...

During development, activity-dependent processes increase the specificity of neural responses to stimuli, but the role that this type of process plays in adult plasticity is unclear. We examined the dynamics of hippocampal activity as animals learned about new environments to understand how neural selectivity changes with experience. Hippocampal principal neurons fire when the animal is located...

1. Oscillatory electro-encephalographic activity at theta frequencies (4-15 Hz) can be recorded from the hippocampus in vivo and depends on intact septal projections. The hypothesis that these oscillations are imposed on the hippocampus by rhythmically active septal inputs was tested using dual intracellular recordings from CA1 and CA3 pyramidal cells in septo-hippocampal cocultures. 2. Septo-h...

Background: GABAergic interneurons in the hippocampal CA1 area are mutually communicated by gap junctions (GJs) composed of connexin36 (Cx36). We examined the role of Cx36 in CA1 in manifestation of kindled seizures and hippocampal kindling in rats. Methods: Quinine, as the specific blocker of Cx36, was injected into CA1, and kindled seizures severity was examined 10 min afterward. Moreover, qu...

In transfected cells and non-neuronal tissues many G-protein-coupled receptors activate p44/42 MAP kinase (ERK), a kinase involved in both hippocampal synaptic plasticity and learning and memory. However, it is not clear to what degree these receptors couple to ERK in brain. G(s)-coupled beta-adrenergic receptor activation of ERK in neurons is critical in the regulation of synaptic plasticity i...

A prevailing view in memory research is that CA3 principally supports spatial processes. However, few studies have investigated the contribution of CA3 to nonspatial memory function. Interestingly, the proximal part of CA3 (close to the dentate gyrus) predominantly projects to distal CA1 (away from the dentate gyrus), which preferentially processes nonspatial information. Moreover, the cytoarch...