Endogenous hippocampal, not peripheral, estradiol is the key factor affecting the novel object recognition abilities of female rats.

Estradiol (E2) is involved in the regulation of emotional behavior, cognitive function, and neuroplasticity. However, peripheral E2 and central E2 levels do not always fluctuate together. The relationships of peripheral and central E2 with cognitive function are not clear.

Different baseline physical activity predicts susceptibility and resilience to chronic social defeat stress in mice: Involvement of dopamine neurons.

Physical inactivity, the fourth leading mortality risk factor worldwide, is associated with chronic mental illness. Identifying the mechanisms underlying different levels of baseline physical activity and the effects of these levels on the susceptibility to stress is very important. However, whether different levels of baseline physical activity influence the susceptibility and resilience to chronic social defeat stress (CSDS), and the underlying mechanisms in the brain remain unclear.

Involvement of D2 receptor in the NAc in chronic unpredictable stress-induced depression-like behaviors.

D2 receptors (D2Rs) located in both pre- and postsynaptic membranes of medium spiny neurons (MSNs) in the nucleus accumbens (NAc) are involved in the stress response and associated behaviors. The role of D2Rs in chronic unpredictable stress (CUS)-induced depression-like behaviors is not clear. Quinpirole (a D2R agonist) and eticlopride (a D2R antagonist) were stereotactically delivered into the NAc before Sprague Dawley rats underwent CUS.

Voluntary Wheel Running Reverses Deficits in Social Behavior Induced by Chronic Social Defeat Stress in Mice: Involvement of the Dopamine System.

Voluntary exercise has been reported to have a therapeutic effect on many psychiatric disorders and social stress is known to impair social interaction. However, whether voluntary exercise could reverse deficits in social behaviors induced by chronic social defeat stress (CSDS) and the underlying mechanism remain unclear. The present study shows CSDS impaired social preference and induced social interaction deficiency in susceptible mice.

Modulation of Kalirin-7 expression by hippocampal CA1 5-HT receptors in spatial memory consolidation.

Serotonin 5-HT1B receptors (5-HT1BRs) are distributed in hippocampal CA1 and play a pivotal role in cognitive function. Activation of 5-HT1BRs regulates synaptic plasticity at the excitatory synapses in the hippocampus. However, the role and its underlying mechanism of 5-HT1BR activation-mediated glutamatergic synaptic plasticity in spatial memory are not fully understood.

Role of proBDNF and BDNF in dendritic spine plasticity and depressive-like behaviors induced by an animal model of depression.

Major depressive disorder (MDD) is one of the most common psychiatric disorder, but the underlying mechanisms are largely unknown. Increasing evidence shows that brain-derived neurotrophic factor (BDNF) plays an important role in the structural plasticity induced by depression. Considering the opposite effects of BDNF and its precursor proBDNF on neural plasticity, we hypothesized that the balance of BDNF and proBDNF plays a critical role in chronic unpredicted mild stress (CUMS)-induced depressive-like behaviors and structural plasticity in the rodent hippocampus.

Orbitofrontal cortex 5-HT2A receptor mediates chronic stress-induced depressive-like behaviors and alterations of spine density and Kalirin7.

Neuroimaging studies show that patients with major depression have reduced volume of the orbitofrontal cortex (OFC). Although the serotonin (5-HT) 2A receptor, which is abundant in the OFC, has been implicated in depression, the underlying mechanisms in the development of stress-induced depression remain unclear. Kalirin-7 (Kal7) is an essential component of mature excitatory synapses for maintaining dendritic spines density, size and synaptic functions.

Dendritic Spines in Depression: What We Learned from Animal Models.

Depression, a severe psychiatric disorder, has been studied for decades, but the underlying mechanisms still remain largely unknown. Depression is closely associated with alterations in dendritic spine morphology and spine density. Therefore, understanding dendritic spines is vital for uncovering the mechanisms underlying depression.

[The interaction between gamma-aminobutyric acid and other related neurotransmitters in depression].

Gamma-aminobutyric acid (GABA) is the major inhibitory neurotransmitter of the central nervous system (CNS) in mammalian, which involved in several mood disorders such as anxiety, depression and schizophrenia. Nowadays, there are growing evidences showed that the depression is concerned with a deficiency in brain GABA. However, there are numerous studies based on the monoamine hypothesis and glutamatergic dysfunction, while the study on GABA is relatively less and scattered.

Progressive alterations of hippocampal CA3-CA1 synapses in an animal model of depression.

Major depressive disorder is the most prevalent psychiatric condition, but the cellular and molecular mechanisms underlying this disorder are largely unknown, although multiple hypotheses have been proposed. The aim of this study was to characterize the progressive alteration of neuronal plasticity in the male rat hippocampus during depression induced by chronic unpredictable mild stress (CUMS), an established animal model of depression. The data in the hippocampus were collected on days 7, 14 and 21 after the onset of three-week CUMS.

Individual aortic baroreceptors are sensitive to different ranges of blood pressures.

Many receptors, including thermal receptors and mechanical receptors, are only activated by stimuli within a clearly defined range of intensities. Differences in the receptive ranges enable individual receptors and their sensory centers to precisely detect the intensity of the stimulus and changes in intensity. Baroreceptors are the sensory terminals of the baroreflex.

[Hippocampus quinolinic acid modulates glutamate and NMDAR/mGluR1 in chronic unpredictable mild stress-induced depression].

The present study was to investigate the role of the quinolinic acid (QUIN) and its relationship with N-methyl-D-aspartic acid (NMDA) receptor and metabotropic glutamate receptor 1 (mGluR1) in depression induced by chronic unpredictable mild stress (CUMS) in hippocampus. CUMS-induced depression model was established in Sprague-Dawley rats. Intrahippocampal injections of QUIN, QUIN antagonist Ro61-8048, non-competitive NMDA receptor antagonist MK-801 and mGluR1 antagonist AIDA were respectively adopted by rat brain stereotaxic coordinates.

[Modulation of hippocampal glutamate and NMDA/AMPA receptor by homocysteine in chronic unpredictable mild stress-induced rat depression].

The study was to investigate the role of homocysteine (Hcy) which was released by hippocampal glial cells and its relationship with NMDA receptor and AMPA receptor in depression induced by chronic unpredictable mild stress (CUMS), and explore the mechanism of changes of Glu/Glu receptor in glial cells and neurons. CUMS-induced depression model was established. The body weight of rats was weighed on the 1st, 7th, 14th, and 21st days during the experiment.

[Research progress of BDNF and depression].

BDNF is widespread existed in CNS and PNS, because of its function in nerve regeneration and restoration, more and more researches focused on the effect of BDNF on neural plasticity in the development of depression and the mechanisms of antidepressant. This article review the basic results and the research trends on BDNF and depression at present, more researches about the interactions of BDNF and proBDNF, BDNF and other transmitters and their receptors should be expected.

[Activation of hippocampal D1 dopamine receptor inhibits glutamate-mediated depression induced by chronic unpredictable mild stress in rats].

The present study was to investigate the role of dopamine D1 receptors and its relationship with glutamate, N-methyl-D-aspartic acid (NMDA) receptor and α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor in depression induced by chronic unpredictable mild stress (CUMS). CUMS-induced depression model was established in Sprague-Dawley rats, and intrahippocampal microinjections of D1 dopamine receptor agonist SKF38393, non-competitive NMDA receptor antagonist MK-801 and AMPA receptor antagonist NBQX were respectively adopted by rat brain stereotaxic coordinates. The behavioral observations were conducted by measurement of weight changes, sucrose preference test, open-field test and tail suspension test.

[Rat orbital frontal (orbital frontal cortex, OFC) GABA B receptor mechanisms in stress and depression].

Stress-induced depression is a kind of functional and structural disability of the brain and involves many neurotransmitters and regions of the brain. A number of studies suggest involvement of γ-Aminobutyric acid (GABA) in the orbital frontal cortex (OFC) in the mechanism of stress-associated depression-like behavior in rodents. However, little work has been done on the relationship between GABA and neural plasticity of the OFC under stress.

[The relationships among raphe magnus nucleus, locus coeruleus and dorsal motor nucleus of vagus in the descending regulation of gastric motility].

Objective: To explore the interrelationship among dorsal motor nucleus of the vagus (DMV), locus coeruleus (LC) and raphe magnus nucleus (NRM) in the mechanism of the descending regulation on gastric motility, which may constitute a parasympathetic local circuit, work as a neural center of gastric modulation in brainstem.

Methods: Using nucleus location, electric stimulation and lesion, together with microinjection, and recording the inter-gastric pressure.

Results: (1) LC stimulation could inhibit the gastric motility significantly (P < 0.

[Antidepressant effect of microinjection of neuropeptide Y into the hippocampus is mediated by decreased expression of nitric oxide synthase].

Accumulating evidence indicates an important role of hippocampal dendrite atrophy in the development of depression, while neuropeptide Y (NPY) participates in hippocampal dendrite growth. The present study was aimed to investigate the relationship between NPY and nitric oxide synthase (NOS) in chronic unpredictable mild stress (CUMS)-induced depression. CUMS-induced depression model was established in Sprague-Dawley rats.

Preventive effect of estrogen on depression-like behavior induced by chronic restraint stress.

Objective: To investigate the roles of estrogen and kalirin-7 in chronic restraint stress (CRS)-induced depression and the pathophysiological mechanism of depression.

Methods: Healthy female mice from Institute of Cancer Research (ICR) were randomly divided into 3 groups: control group, CRS group, and estrogen + CRS group. CRS was used to establish the animal model of depression.

[Involvement of hippocampal NMDA receptor and neuropeptide Y in depression induced by chronic unpredictable mild stress].

The present study was aimed to investigate the role and relationship between N-methyl-D-aspartic acid (NMDA) receptor and neuropeptide Y (NPY) in depression induced by chronic unpredictable mild stress (CUMS). CUMS-induced depression model was established in Sprague-Dawley rats. Intrahippocampal injections of NMDA, non-competitive NMDA receptor antagonist MK-801 and NPY-Y1 receptor antagonist GR231118 were respectively adopted by rat brain stereotaxic coordinates.

[The association of hippocampal glutamate with depression and the effects on gastric mobility].

Aim: To explore the relationship between the pathology of depression and glutamate (Glu) in hippocampus, and the effect on gastric mobility.

Methods: Depression model was established by using the chronic unpredicted mild stress (CUMS). And stereotaxic and intra-hippocampal microinjection were also used in this experiment.

[Effect and mechnaisim of GLU and GABA in OFC on gastric motility].

Aim: To Investigate the effect of glutamate (Glu) and gamma-aminobutyric acid(GABA) in orbitofrontal cortex (OFC) on regulation of gastric motility.

Methods: Using microinjection in OFC,together with lesion of related nucleus,and recording the intragastric pressure(IGP).

Results: (1) Microinjection of Glu in OFC caused a significant reduce of the amplitude of gastric motility, this effect could be reverse by lesion of amygdala, while lesion of LC had no influence on the effect of Glu.

Prevention of chronic stress-induced depression-like behavior by inducible nitric oxide inhibitor.

Depression is associated with significant morbidity and functional disability, and it is thus important to reveal the mechanism of depression. A variety of studies suggest an involvement of neuronal nitric oxide synthase in the pathophysiological mechanism of none-stress-associated depression-like behavior in rodents. It is unknown, however, whether inducible nitric oxide synthase (iNOS) also makes contributions to the mechanism of depression.

[The effect of sodium 4',7-bihydroxylisoflavone-sulfonate on gastric motility and its mechanism in rat].

Aim: To explore the effect of sodium 4',7-bihydroxylisoflavone-sulfonate (SBIS) on gastric motility in rats and to analyse its mechanisms.

Methods: Using intraperitoneal (ip) injection and intracerebroventriular (icv) microinjection of drugs and recording the frequency and amplitude of contraction of gastric motility.

Results: (1) The injection (ip) of different doses of SBIS could decrease the amplitude of gastric motility, but it wasn't a dose-dependent effect.