Recent behavioral studies indicate that conditioned fear response to contextual stimuli is reduced effectively by anxiolytic 5-hydroxytryptame (5-HT)1A agonists. Since the hippocampus seems to play an essential role in associative fear memories evoked by context, it is important to assess the effect of 5-HT1A agonists on pyramidal cell activity in the hippocampus. We examined the effects of 5-H...

The hippocampus sends efferent fibers to the subiculum, which projects to the entorinal cortex. Previous studies suggest that the hippocampal CA1 area may receive a projection back from the subiculum. This hypothesis was tested using whole cell recording from CA1 pyramidal cells while subicular neurons were selectively stimulated with focal flash photolysis of caged glutamate, which avoids stim...

Two days following one-week administration of the benzodiazepine, flurazepam (FZP), rats exhibit anticonvulsant tolerance in vivo, while reduced GABA(A) receptor-mediated inhibition and enhanced EPSP amplitude are present in CA1 pyramidal neurons in vitro. AMPA receptor (AMPAR)-mediated synaptic transmission in FZP-treated rats was examined using electrophysiological techniques in in vitro hipp...

Gamma frequency (30-80 Hz) oscillations are implicated in memory processing. Such rhythmic activity can be generated intrinsically in the CA3 region of the hippocampus from where it can propagate to the CA1 area. To uncover the synaptic mechanisms underlying the intrahippocampal spread of gamma oscillations, we recorded local field potentials, as well as action potentials and synaptic currents ...

The dendritic length and dendritic-spine density of the pyramidal neurons of the prefrontal cortex and the CA1 hippocampus of rats using the nonselective nitric oxide synthase inhibitor N-omega-nitro-L-arginine (L-NNA) at different postnatal day (P) periods of the brain development (P1-P3, P4-P6, and P7-P9) were assessed using Golgi-Cox staining after puberty (P60). At P4-P6, the L-NNA treatmen...

The endocannabinoid system negatively regulates the release of various neurotransmitters in an activity-dependent manner, thereby influencing the excitability of neuronal circuits. In the hippocampus, cannabinoid type 1 (CB1) receptor is present on both GABAergic and glutamatergic axon terminals. CB1 receptor-deficient mice were previously shown to have increased hippocampal long-term potentiat...

Excitatory synaptic activity in horizontal stratum oriens-alveus interneurons (OAIs) is driven by the recurrent collaterals of CA1 pyramidal cells and is strongly influenced by protocols that elicit synaptic plasticity in these principal neurons. Induction of LTD in the Schaffer collateral-CA1 pyramidal neuron synapse causes a passive down-regulation of stratum radiatum-evoked excitatory synapt...

Patients with early infantile epileptic encephalopathy (EIEE) experience severe seizures and cognitive impairment and are at increased risk for sudden unexpected death in epilepsy (SUDEP). EIEE13 [Online Mendelian Inheritance in Man (OMIM) # 614558] is caused by de novo missense mutations in the voltage-gated sodium channel gene SCN8A Here, we investigated the neuronal phenotype of a mouse mode...

background and objective: although diabetes mellitus is known to be one of the risk factors for dementia but neuropathic changes in the brain of diabetic patients have not been completely revealed. therefore, this research study was done to evaluate structural changes in pyramidal neurons of hippocampal ca1 area of male diabetic rats using golgi-impregnation method. materials and methods: male ...