In this study, the effect of an experimentally increased excitability in hippocampal neurons, via hippocampal kindling, on amygdala kindling rate was investigated in rats. Animals were divided into 4 groups. In all groups, except group 2, tripolar electrodes were implanted in the amygdala and CAI region of the dorsal hippocampus. Group 2 animals were only implanted with tripolar electrodes in...

A population of human hippocampal neurons has shown responses to individual concepts (e.g., Jennifer Aniston) that generalize to different instances of the concept. However, recordings from the rodent hippocampus suggest an important function of these neurons is their ability to discriminate overlapping representations, or pattern separate, a process that may facilitate discrimination of simila...

We have explored the ability of axons from spinal and hippocampal neurons to aggregate NMDA- and AMPA-type glutamate receptors on each other as a way of exploring the molecular differences between their presynaptic elements. Spinal axons, which normally cluster only AMPA-type glutamate receptors on other spinal neurons, cluster both AMPA- and NMDA-type glutamate receptors on the dendritic shaft...

To better understand the mechanisms of hippocampal-cortical signalling for mnemonic function and behavior, we recorded ventral hippocampal local field potentials (LFPs) simultaneously with ensemble neural activity and LFPs in the prefrontal cortex in rats learning and switching strategies in a Y-maze variant of the Wisconsin Card Sorting Task. Behaviorally correlated activity of individual neur...

Epilepsy can cause cerebral transient dysfunctions. Ganoderma lucidum spores (GLS), a traditional Chinese medicinal herb, has shown some antiepileptic effects in our previous studies. This was the first study of the effects of GLS on cultured primary hippocampal neurons, treated with Mg(2+) free medium. This in vitro model of epileptiform discharge hippocampal neurons allowed us to investigate ...

Besides regulating energy balance and reducing body-weight, the adipokine leptin has been recently shown to be neuroprotective and antiapoptotic by promoting neuronal survival after excitotoxic and oxidative insults. Here, we investigated the firing properties of mouse hippocampal neurons and the effects of leptin pretreatment on hypoxic damage (2 hours, 3% O(2)). Experiments were carried out b...

Corticotropin-releasing hormone (CRH) signaling in the hippocampus has been established to be important for mediating the effects of stress on learning and memory. Given our laboratory's recent characterization of a subset of hippocampal CRH neurons as a novel class of GABAergic interneurons, we hypothesized that these local GABAergic hippocampal CRH neurons may influence hippocampal function. ...

introduction: cholinergic systems are involved in learning and memory. scopolamine, a muscarinic acetylcholine receptor antagonist, is used as a standard/ reference drug for inducing cognitive deficits in healthy humans and animals. the purpose of this study was to evaluate the effects of scopolamine on avoidance memory and number of neurons in rat’s hippocampus. . methods: thirty five male alb...

Recent studies have reported the existence of hippocampal "time cells," neurons that fire at particular moments during periods when behavior and location are relatively constant. However, an alternative explanation of apparent time coding is that hippocampal neurons "path integrate" to encode the distance an animal has traveled. Here, we examined hippocampal neuronal firing patterns as rats ran...

Plasticity in the adult brain enables lifelong learning. The fundamental mechanism of adult neural plasticity is activity-dependent reorganization of pre-existing structure, in contrast to the widespread cellular proliferation and migration that occurs during development. Whereas adult hippocampal dentate gyrus continuously generates cohorts of neurons, and newborn neurons integrate into the ex...