Activation of the CXCR4 Receptor by Chemokine CXCL12 Increases the Excitability of Neurons in the Rat Central Amygdala.

Primarily regarded as immune proteins, chemokines are emerging as a family of molecules serving neuromodulatory functions in the developing and adult brain. Among them, CXCL12 is constitutively and widely expressed in the CNS, where it was shown to act on cellular, synaptic, network, and behavioral levels. Its receptor, CXCR4, is abundant in the amygdala, a brain structure involved in pathophysiology of anxiety disorders.

Posterior hypothalamic theta rhythm: Electrophysiological basis and involvement of glutamatergic receptors.

The posterior hypothalamic area (PHa), including the supramammillary nucleus (SuM) and posterior hypothalamic nuclei, forms a crucial part of the ascending brainstem hippocampal synchronizing pathway, that is involved in the frequency programming and modulation of rhythmic theta activity generated in limbic structures. Recent investigations show that in addition to being a modulator of limbic theta activity, the PHa is capable of producing well-synchronized local theta field potentials by itself. The purpose of this study was to examine the ability of the PHa to generate theta field potentials and accompanying cell discharges in response to glutamatergic stimulation under both in vitro and in vivo conditions.

Lamotrigine Attenuates Neuronal Excitability, Depresses GABA Synaptic Inhibition, and Modulates Theta Rhythms in Rat Hippocampus.

Theta oscillations generated in hippocampal (HPC) and cortical neuronal networks are involved in various aspects of brain function, including sensorimotor integration, movement planning, memory formation and attention. Disruptions of theta rhythms are present in individuals with brain disorders, including epilepsy and Alzheimer's disease. Theta rhythm generation involves a specific interplay between cellular (ion channel) and network (synaptic) mechanisms.

Cellular, synaptic, and network effects of chemokines in the central nervous system and their implications to behavior.

Accumulating evidence highlights chemokines as key mediators of the bidirectional crosstalk between neurons and glial cells aimed at preserving brain functioning. The multifaceted role of these immune proteins in the CNS is mirrored by the complexity of the mechanisms underlying its biological function, including biased signaling. Neurons, only in concert with glial cells, are essential players in the modulation of brain homeostatic functions.

5-HT receptors enhance inhibitory synaptic input to principal neurons in the mouse basal amygdala.

The basal amygdala (BA) has been implicated in encoding fear and its extinction. The level of serotonin (5-HT) in the BA increases due to arousal and stress related to aversive stimuli. The effects of 5-HT receptor (5-HTR) activation and blockade on the activity of BA neurons have not yet been investigated.

5-HT receptors increase the excitability of hippocampal CA1 pyramidal neurons by inhibiting the A-type potassium current.

Accumulating evidence suggests a widespread role of serotonin 5-HT receptors (5-HTRs) in the physiology of cognitive and affective processing. However, we still lack insights into 5-HTR electrophysiology. Studies analyzing the 5-HTR-mediated changes in CA1 pyramidal neuron activity revealed that 5-HTR activation leads to the opening of hyperpolarization-activated cyclic nucleotide-gated cation channels (HCNs).

Astrocytes determine conditioned response to morphine via glucocorticoid receptor-dependent regulation of lactate release.

To date, neurons have been the primary focus of research on the role of glucocorticoids in the regulation of brain function and pathological behaviors, such as addiction. Astrocytes, which are also glucocorticoid-responsive, have been recently implicated in the development of drug abuse, albeit through as yet undefined mechanisms. Here, using a spectrum of tools (whole-transcriptome profiling, viral-mediated RNA interference in vitro and in vivo, behavioral pharmacology and electrophysiology), we demonstrate that astrocytes in the nucleus accumbens (NAc) are an important locus of glucocorticoid receptor (GR)-dependent transcriptional changes that regulate rewarding effects of morphine.

Hyperforin Potentiates Antidepressant-Like Activity of Lanicemine in Mice.

N-methyl-D-aspartate receptor (NMDAR) modulators induce rapid and sustained antidepressant like-activity in rodents through a molecular mechanism of action that involves the activation of Ca dependent signaling pathways. Moreover, ketamine, a global NMDAR antagonist is a potent, novel, and atypical drug that has been successfully used to treat major depressive disorder (MDD). However, because ketamine evokes unwanted side effects, alternative strategies have been developed for the treatment of depression.

The 5-HT receptor antagonist SB 269970 ameliorates corticosterone-induced alterations in 5-HT receptor-mediated modulation of GABAergic transmission in the rat dorsal raphe nucleus.

Rationale: Chronic stress and corticosterone have been shown to affect serotonin (5-HT) neurotransmission; however, the influence of stress on the activity of the dorsal raphe nucleus (DRN), the main source of 5-HT in the forebrain, is not well understood. In particular, it is unknown if and how stress modifies DRN 5-HT receptors, which are involved in the modulation of the firing of local inhibitory interneurons responsible for regulating the activity of DRN projection cells.

Objectives: Our study aimed to investigate the effect of repeated corticosterone injections on the modulation of the inhibitory transmission within the DRN by 5-HT receptors and whether it could be reversed by treatment with a 5-HT receptor antagonist.

Prenatal stress affects viability, activation, and chemokine signaling in astroglial cultures.

CXCL12/SDF-1α and CX3CL1/fractalkine are constitutively expressed in the brain, which indicates their significant functions. Emerging evidence highlights the role of astrocytes and the immune system in the pathophysiology of stress-related disorders. The aim of this study was to assess whether prenatal stress affects chemokine signaling, cell viability/activation, and the iNOS pathway in astroglial cultures.

Universal Visual Features Might Be Necessary for Fluent Reading. A Longitudinal Study of Visual Reading in Braille and Cyrillic Alphabets.

It has been hypothesized that efficient reading is possible because all reading scripts have been matched, through cultural evolution, to the natural capabilities of the visual cortex. This matching has resulted in all scripts being made of line-junctions, such as T, X, or L. Our aim was to test a critical prediction of this hypothesis: visual reading in an atypical script that is devoid of line-junctions (such as the Braille alphabet read visually) should be much less efficient than reading in a "normal" script (e.