The Cornu Ammonis-1 (CA1) subfield and subiculum (SUB) serve as major output structures of the hippocampal formation. Exploring forms of synaptic plasticity simultaneously within these two output regions may improve understanding of the dynamics of hippocampal circuitry and information transfer between hippocampal and cortical brain regions. Using a novel dual-channel electrophysiological prepa...

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...

Apamin-sensitive, small-conductance, Ca2+-activated K+ channels (SK channels) modulate neuronal excitability in CA1 neurons. Blocking all SK channel subtypes with apamin facilitates the induction of hippocampal synaptic plasticity and enhances hippocampal learning. In CA1 dendrites, SK channels are activated by Ca2+ through NMDA receptors and restrict glutamate-mediated EPSPs. Studies of SK cha...

Learning and memory effects of angiotensin II (Ang II) microinjected unilaterally (left or right) and bilaterally into hippocampal CA1 area on the background of the inhibited hippocampal angiotensin 1 receptors type (AT1) of male Wistar rats were studied. It was found that the combination (losartan 100 micrograms + Ang II 0.5 micrograms) microinjected bilaterally or into the left CA1 area impro...

BACKGROUND Hippocampal atrophy is a well-known feature of Alzheimer's disease (AD), but sensitivity and specificity of hippocampal volumetry are limited. Neuropathological studies have shown that hippocampal subfields are differentially vulnerable to AD; hippocampal subfield volumetry may thus prove to be more accurate than global hippocampal volumetry to detect AD. METHODS CA1, subiculum and...

Population bursts of the CA3 network, which occur during eating, drinking, awake immobility, and slow-wave sleep, produce a large field excitatory postsynaptic potential throughout stratum radiatum of the CA1 field (sharp wave). The CA3 burst sets into motion a short-lived, dynamic interaction between CA1 pyramidal cells and interneurons, the product of which is a 200 Hz oscillatory field poten...

Models of hippocampal function have proposed different functions for hippocampal regions CA3 and CA1, commonly proposing that CA1 performs a match-mismatch comparison of memory retrieval with sensory input. The study by I. Lee, M. R. Hunsaker, and R. P. Kesner (2005) tested these models using selective lesions of hippocampal subregions (see record 2005-01705-014). Their data suggest that CA3 an...

introduction: stress is defined as any environmental change that disturbs the maintenance of brain homeostasis. stress leads to production of pro-inflammatory cytokines that provoke neurodegenerative disorders. in the present study, we investigated the effects of dalteparin on hippocampal neuronal death induced by chronic stress in rats. methods: the study was carried out on 60 adult male wista...

Abstract* Introduction: Chronic morphine exposure can cause addiction and affect synaptic plasticity, but the underlying neural mechanisms of this phenomenon remain unknown. Herein we used electrophysiologic approaches in hippocampal CA1 area to examine the effect of chronic morphine administration on short-term plasticity. Methods: Experiments were carried out on hippocampal slices taken f...

Hippocampal function is important for learning and memory. During memory processing, hippocampal CA1 neurons play a crucial role by integrating excitatory synaptic input from CA3 and the entorhinal cortex. These neurons receive excitatory input almost exclusively on dendritic spines. The formation and elimination--structural plasticity--of dendritic spines reflect wiring changes within the hipp...