CA3 and subiculum are hippocampal formation regions that can initiate seizure activity because each has a substantial intrinsic excitatory connectivity. We studied the intrinsic connectivity of area CA1 by exploring the spread of synchronous population discharges in ventral hippocampal slices from rats using a recording chamber that permitted multiple simultaneous extracellular recordings along...

Studies on human and animals shed light on the unique hippocampus contributions to relational memory. However, the particular role of each hippocampal subregion in memory processing is still not clear. Hippocampal computational models and theories have emphasized a unique function in memory for each hippocampal subregion, with the CA3 area acting as an autoassociative memory network and the CA1...

Background: It is believed that cognitive processing is easily disturbed by incompatible environmental stimulations. Many studies have shown that prenatal stress affects fetal brain development. The aim of this study was to evaluate the effect of noise pollution exposure during conception period on neural activity of hippocampus CA1 area in male rat offspring. Methods: Four groups of rats inclu...

Hippocampal CA3 area generates temporally structured network activity such as sharp waves and gamma and theta oscillations. Parvalbumin-expressing basket cells, making GABAergic synapses onto cell bodies and proximal dendrites of pyramidal cells, control pyramidal cell activity and participate in network oscillations in slice preparations, but their roles in vivo remain to be tested. We have re...

Egr1, a member of the Egr family of transcription factors, and Arc are immediate early genes known to play major roles in synaptic plasticity and memory. Despite evidence that Egr family members can control Arc transcriptional regulation, demonstration of a selective role of Egr1 alone is lacking. We investigated the extent to which activity-dependent Arc expression is dependent on Egr1 by anal...

Hippocampal μ-opioid receptors (MOR) have been implicated in memory formation associated with opiate drug abuse. MORs modulate hippocampal synaptic plasticity acutely, when chronically activated, and during drug withdrawal. At the network level, MORs increase excitability in area CA1 by disinhibiting pyramidal cells. The precise inhibitory interneuron subtypes affected by MOR activation are unk...

Hippocampal mu-opioid receptors (MORs) have been implicated in memory formation associated with opiate drug abuse. MORs modulate hippocampal synaptic plasticity acutely, when chronically activated, and during drug withdrawal. At the network level, MORs increase excitability in area CA1 by disinhibiting pyramidal cells. The precise inhibitory interneuron subtypes affected by MOR activation are u...

The metabotropic glutamate receptors (mGluRs) have many important roles in regulation of neuronal excitability and synaptic transmission. In hippocampal area CA1, activation of mGluRs can reduce both excitatory and inhibitory synaptic transmission. The conventional view is that the presynaptic effects are mediated by L-2-amino-4-phosphonobutyric acid (L-AP4)-sensitive, or group III mGluRs (mGlu...

Neuron loss, axon sprouting, and the formation of new synaptic circuits have been hypothesized to contribute to seizures in temporal lobe epilepsy (TLE). Using the kainate-treated rat, we examined how alterations in the density of CA1 pyramidal cells and interneurons, and subsequent sprouting of CA1 pyramidal cell axons, were temporally associated with functional changes in the network properti...