RESUMEN
Depressive disorder ranks as a major bur-den of disease worldwide,yet the current antidepressant medications are limited by frequent non-responsiveness and significant side effects.The lateral septum(LS)is thought to control of depression,however,the cellular and circuit substrates are largely unknown.Here,we identified a subpopulation of LS GABAergic adenosine A2A receptors(A2AR)-positive neurons mediating depres-sive symptoms via direct projects to the lateral habenula(LHb)and the dorsomedial hypothalamus(DMH).Activa-tion of A2AR in the LS augmented the spiking frequency of A2AR-positive neurons leading to a decreased activation of surrounding neurons and the bi-directional manipula-tion of LS-A2AR activity demonstrated that LS-A2ARs are necessary and sufficient to trigger depressive pheno-types.Thus,the optogenetic modulation(stimulation or inhibition)of LS-A2AR-positive neuronal activity or LS-A2AR-positive neurons projection terminals to the LHb or DMH,phenocopied depressive behaviors.Moreover,A2AR are upregulated in the LS in two male mouse mod-els of repeated stress-induced depression.This identifica-tion that aberrantly increased A2AR signaling in the LS is a critical upstream regulator of repeated stress-induced depressive-like behaviors provides a neurophysiological and circuit-based justification of the antidepressant poten-tial of A2AR antagonists,prompting their clinical transla-tion.
RESUMEN
Objective To establish an animal model of rapid eye movement (REM) sleep deprivation (SD) and an animal model for perifornical nucleus microdialysis and investigate the change of cognition, hypocretinergic system and GABAergic system in rats' hypothalamus after various degrees of REM sleep deprivation and sleep revival and two GABAergic drugs intervention. Methods The modified multiple platform method (MMPM)was used to establish sleep deprivation model and the cognitive function was assessed by Morris' water maze. Immunofluorescence technique was used to analyze the number of Hypocretin (Hcrt) immunoreactive neurons, total Fos immunoreactive neurons, Hcrt and Fos colabeled neurons, and the integrated optical density ( IA ) of GABAA Rαl immunoreactive area in rats' hypothalamus.High performance liquid chromatograph (HPLC) was used to quantitatively analyze the level of GABA and Gluin in the rats' hypothalamus. Two GABAergic drugs, a selective GABAA R antagonist, SR-95531, and a selective blocker of type 1 GABA transporter (uptake blocker), NO-711, were used for perifornical nucleus microdialysis. Results There was no statistically significant difference in tests between CC and TC ( Define CC and TC). There was a significant decrease (P ＜ 0. 05 ) of cognitive function measured by Morris maze test in SD 3 d, SD 5 d and RS 6 h of SD groups compared with CC and TC groups. Number of Fos immunoreactive, F+ &H+ immunoreactive neuronsand IA of GABAA Rαl immunoreactive area were all significantly increased ( P ＜ 0. 05 ). Content of GABA measured by HPLC was also increased ( P ＜ 0. 05 ). However, all these changes were partly reversed by sleep revival SR-95531 and NO-711 had different effect on these changes. Conclusions Sleep deprivation, no matter mild or severe, has adverse effects on cognitive function. Activities of both GABAergic and Hcrtergic system are increased during REMSD. These two neurons system could be regulated by each other and the relationship between them is positive correlation. GABAergic system also had self-regulation during REMSD, but microdialysision of either SR-95531 or NO-711 acquired adverse effects on cognitive function of rats. So GABAergic system is not an optimal therapeutic target. Because GABAergic and Hcrtergic system has inhibitory effect on each other,suppressing activity of Hcrtergic system might be a promising therapeutic target.
RESUMEN
This study is to investigate the influence and mechanism of action of asymmetrical dimethylarginine (ADMA) and the induced oxidative stress level on Alzheimer's disease (AD) incidence. ADMA concentration, nitric oxide, Abeta(40)/Abeta(42) ratio, inducible NO synthase (iNOS) activity and the concentrations of the induced free radicals including malondialdehyde (MDA), 3-nitrotyrosine (3-NT) and peroxynitrite (ONOO-) in the cerebrospinal fluid (CSF) from 34 neurologically normal controls and 37 AD patients were quantitatively determined and statistically compared. The results showed that the ADMA concentration significantly decreased in AD patients, and it showed negative correlation with the NO, iNOS activity, and showed positive correlation with MMSE score. ADMA concentration was negatively correlated with Abeta(40)/Abeta(42) ratio (P<0.01) with the observation that Abeta(40)/Abeta(42) ratio increased while ADMA level decreased in CSF in AD patients. The concentration levels of MDA, 3-NT and ROS significantly increased compared with the control with all the P values less than 0.05. These findings suggested that the ADMA disorder and the oxidative damage effect of the induced free radicals in CSF of AD patients are an important mechanism of AD incidence, and their joint regulation may provide new idea for the prevention and clinical treatment of AD.
RESUMEN
The P2X7 receptor mRNA and proteins in guinea-pig dorsal root ganglia (DRG) were studied by using RT-PCR and immunohistochemistry. The co-localization of P2X7 receptor with four cytochemical markers, the neurofilament protein NF200, S100, substance P and isolectin B4 (IB4) binding glyco-conjugates, were also examined. It was found that P2X7 receptor immunoreactivity (P2X7R-IR) was present mostly in large- and medium-sized DRG neurons (62 %±9 % and 36 %±6 % respectively in all P2X7R-IR neurons). All the P2X7R-IR neurons were also NF200 and S100 immunopositive. However, in a small number of NF200 or S100 immunopositive neurons no P2X7R-IR was detectable. All the IB4-positive or substance P-immunopositive neurons had no P2X7R-IR. These results demonstrate that P2X7 receptors are expressed in a large subpopulation of DRG neurons and they may play a role in the transduction of specific peripheral sensory signals.
RESUMEN
Objective: To observe the level of pro-opiomelanocortin (POMC) mRNA expression in the hypothalamic arcuate nucleus in young and senile rats. Methods: POMC mRNA was determined with in situ hybridization, the hybridization signals and areas of POMC mRNA-positive cells were measured with computer image analysis system. Results: Compared with young rats, average gray values of POMC mRNA-positive neurons in the hypothalalmic arcuate nucleus and near region in the senile rats decreased, but the numbers of POMC mRNA-positive neurons did not change significantly. Conclusion: The decrease of POMC mRNA expression level in individual neurons in hypothalamic arcuate nucleus of senile rats is one of the causes that decrease the expression of peptides-derived from POMC gene.
RESUMEN
With the immunocytochemical PAP-floating method we studied the effects of foot-shock, cold and scalding on Dynorphin B (Dyn B) neurons in the rat hypothalamus. The results showed that in the foot-shock condition, the anteroposterior diameter of PVH (paraventricular nucleus of hypothalamus) and PVM (paraventricular nucleus of hypothalamus, medial part) with Dyn B neurons, the total number of Dyn B neurons in PVH and the number of thick fibers in SON (supraoptic nucleus) and PVH were increased obviously; in the cold condition there was declining tendency of the total number of Dyn B neurons in PVH; and in the scalding condition the staining density of median eminence was much deeper than that in normal condition. These results imply that Dyn B neurons in the rat hypothalamus is associated with these stress responses.
RESUMEN
Effect of scalding on secretory function of beta-endorphin neuron in the arcuate nucleus of the rat hypothalamus was studied semiquantitatively using immunocytochemistry and image analysis. The results showed that the number of beta-endorphin neurons and area of positive products reduced significantly (P