Effect of the closed-loop hippocampal low-frequency stimulation on seizure severity, learning, and memory in pilocarpine epilepsy rat model.

Aims: In this study, the anticonvulsant action of closed-loop, low-frequency deep brain stimulation (DBS) was investigated. In addition, the changes in brain rhythms and functional connectivity of the hippocampus and prefrontal cortex were evaluated.

Methods: Epilepsy was induced by pilocarpine in male Wistar rats.

Comparing the synaptic potentiation in schaffer collateral-CA1 synapses in dorsal and intermediate regions of the hippocampus in normal and kindled rats.

There is growing evidence that the hippocampus comprises diverse neural circuits that exhibit longitudinal variation in their properties, however, the intermediate region of the hippocampus has received comparatively little attention. Therefore, this study was designed to compared short- and long-term synaptic plasticity between the dorsal and intermediate regions of the hippocampus in normal and PTZ-kindled rats. Short-term plasticity was assessed by measuring the ratio of field excitatory postsynaptic potentials' (fEPSPs) slope in response to paired-pulse stimulation at three different inter-pulse intervals (20, 80, and 160 ms), while long-term plasticity was assessed using primed burst stimulation (PBS).

Effect of low frequency stimulation of olfactory bulb on seizure severity, learning, and memory in kindled rats.

Low frequency deep brain electrical stimulation (LFS) is a potential therapeutic strategy to control seizures in epilepsy patients. Given the functional connection of the olfactory bulb with the hippocampal formation, in this study the effect of applying LFS in the olfactory bulb on seizure severity, and learning and memory was investigated in hippocampal kindling. In male Wistar rats (250-300 g), a tripolar electrode was inserted in the CA1 region of the right hippocampus to apply kindling stimulations and record the afterdischarges (ADs).

A corollary discharge mediates saccade-related inhibition of single units in mnemonic structures of the human brain.

Despite the critical link between visual exploration and memory, little is known about how neuronal activity in the human mesial temporal lobe (MTL) is modulated by saccades. Here, we characterize saccade-associated neuronal modulations, unit-by-unit, and contrast them to image onset and to occipital lobe neurons. We reveal evidence for a corollary discharge (CD)-like modulatory signal that accompanies saccades, inhibiting/exciting a unique population of broad-/narrow-spiking units, respectively, before and during saccades and with directional selectivity.

Group I metabotropic glutamate receptors contribute to the antiepileptic effect of electrical stimulation in hippocampal CA1 pyramidal neurons.

Low-frequency deep brain stimulation (LFS) inhibits neuronal hyperexcitability during epilepsy. Accordingly, the use of LFS as a treatment method for patients with drug-resistant epilepsy has been proposed. However, the LFS antiepileptic mechanisms are not fully understood.

Alpha adrenergic receptors have role in the inhibitory effect of electrical low frequency stimulation on epileptiform activity in rats.

Low frequency stimulation (LFS) inhibits neuronal hyperexcitability following epileptic activity. However, knowledge about LFS' inhibitory mechanisms is lacking. Here, α and α adrenergic receptors' roles in mediating LFS inhibitory action on high-K induced epileptiform activity (EA) was examined in rat hippocampal slices.

Deep brain stimulation effects on learning, memory and glutamate and GABA receptor subunit gene expression in kindled rats.

Epileptic seizures are accompanied by learning and memory impairments. In this study, the effect of low frequency stimulation (LFS) on spatial learning and memory was assessed in kindled animals and followed for one month. Fully kindled rats received LFS at 4 times (immediately, 6 h, 24 h and 30 h following the final kindling stimulation).

The role of α adrenergic receptors in mediating the inhibitory effect of electrical brain stimulation on epileptiform activity in rat hippocampal slices.

The Inhibitory effect of electrical low-frequency stimulation (LFS) on neuronal excitability and seizure occurrence has been indicated in experimental models, but the precise mechanism has not established. This investigation was intended to figure out the role of α and α adrenergic receptors in LFS' inhibitory effect on neuronal excitability. Epileptiform activity induced in an in vitro rat hippocampal slice preparation by high K ACSF and LFS (900 square wave pulses at 1 Hz) was administered at the beginning of epileptiform activity to the Schaffer collaterals.

Allergic rhinitis impairs working memory in association with drop of hippocampal - Prefrontal coupling.

Allergic rhinitis (AR) is a chronic inflammatory disease frequently associated with a deficit in learning and memory. Working memory is an important system for decision making and guidance, which depends on interactions between the ventral hippocampus (vHipp) and the prelimbic prefrontal cortex (plPFC). It is still unclear whether AR influences the activity and coupling of these brain areas, which consequently may impair working memory.

The role of dopamine D-like receptors in a "depotentiation-like effect" of deep brain stimulation in kindled rats.

The mechanisms involved in the anti-seizure effects of low-frequency stimulation (LFS) have not been completely determined. However, G-protein-coupled receptors, including D-like receptors, may have a role in mediating these effects. In the present study, the role of D-like receptors in LFS' anti-seizure action was investigated.

Allergen-induced anxiety-like behavior is associated with disruption of medial prefrontal cortex - amygdala circuit.

Anxiety is prevalent in asthma, and is associated with disease severity and poor quality of life. However, no study to date provides direct experimental evidence for the effect of allergic inflammation on the structure and function of medial prefrontal cortex (mPFC) and amygdala, which are essential regions for modulating anxiety and its behavioral expression. We assessed the impact of ovalbumin (OVA)-induced allergic inflammation on the appearance of anxiety-like behavior, mPFC and amygdala volumes using MRI, and the mPFC-amygdala circuit activity in sensitized rats.

Intrahippocampal 5-HT receptor antagonist inhibits the improving effect of low-frequency stimulation on memory impairment in kindled rats.

In addition to its anticonvulsant effect, low frequency stimulation (LFS) improves learning and memory in kindled animals. In the present study, the role of 5-HT receptors in mediating LFS' improving effect on spatial learning and memory was investigated in amygdala-kindled rats. Amygdala kindling was conducted in a semi-rapid kindling stimulations (12 stimulations per day) in male Wistar rats.

Low-Frequency Electrical Stimulation Reduces the Impairment in Synaptic Plasticity Following Epileptiform Activity in Rat Hippocampal Slices through α, But Not α, Adrenergic Receptors.

Low frequency stimulation (LFS) has anticonvulsant effect and may restore the ability of long-term potentiation (LTP) to the epileptic brain. The mechanisms of LFS have not been completely determined. Here, we showed that LTP induction was impaired following in vitro epileptiform activity (EA) in hippocampal slices, but application of LFS prevented this impairment.

The inhibitory effect of different patterns of low frequency stimulation on neuronal firing following epileptiform activity in rat hippocampal slices.

Low frequency stimulation (LFS) has inhibitory effect on hyperexcitability during epileptic states. However, knowledge is lacking about LFS patterns that can exert an optimal antiepileptic effect. In this study, the effect of different numbers of pulses and current intensities of 1 Hz LFS applied at various time points of epileptiform activity was evaluated in high-K model of epileptiform activity (EA).

The role of 5-HT receptors of hippocampal CA1 region in anticonvulsant effects of low-frequency stimulation in amygdala kindled rats.

Low frequency stimulation (LFS) has been proposed as a method in the treatment of epilepsy, but its anticonvulsant mechanism is still unknown. In the current study, the hippocampal CA1 region was microinjected with NAD-299 (a selective 5-HT antagonist), and its role in mediating the inhibitory action of LFS on amygdala kindling was investigated. Male Wistar rats were kindled by amygdala stimulation in a semi-rapid kindling manner (12 stimulations per day).

Nature and extent of person recognition impairments associated with Capgras syndrome in Lewy body dementia.

Patients with Capgras syndrome (CS) adopt the delusional belief that persons well-known to them have been replaced by an imposter. Several current theoretical models of CS attribute such misidentification problems to deficits in covert recognition processes related to the generation of appropriate affective autonomic signals. These models assume intact overt recognition processes for the imposter and, more broadly, for other individuals.

Reach adaptation and proprioceptive recalibration following terminal visual feedback of the hand.

We have shown that when subjects reach with continuous, misaligned visual feedback of their hand, their reaches are adapted and proprioceptive sense of hand position is recalibrated to partially match the visual feedback (Salomonczyk et al., 2011). It is unclear if similar changes arise after reaching with visual feedback that is provided only at the end of the reach (i.

Representational demands modulate involvement of perirhinal cortex in face processing.

The classic view holds that the medial temporal lobes (MTL) are dedicated to declarative memory functioning. Recent evidence, however, suggests that perirhinal cortex (PrC), a structure within the anterior MTL, may also play a role in perceptual discriminations when representations of complex conjunctions of features, or of gestalt-characteristics of objects must be generated. Interestingly, neuroimaging and electrophysiological recordings in nonhuman primates have also revealed a face patch in the anterior collateral sulcus with preferential responses to face stimuli in various task contexts.