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Context-induced retrieval of drug withdrawal memory is one of the important reasons for drug relapses. Previous studies have shown that different projection neurons in different brain regions or in the same brain region such as the basolateral amygdala (BLA) participate in context-induced retrieval of drug withdrawal memory. However, whether these different projection neurons participate in the retrieval of drug withdrawal memory with same or different molecular pathways remains a topic for research. The present results showed that (1) BLA neurons projecting to the prelimbic cortex (BLA-PrL) and BLA neurons projecting to the nucleus accumbens (BLA-NAc) participated in context-induced retrieval of morphine withdrawal memory; (2) there was an increase in the expression of Arc and pERK in BLA-NAc neurons, but not in BLA-PrL neurons during context-induced retrieval of morphine withdrawal memory; (3) pERK was the upstream molecule of Arc, whereas D1 receptor was the upstream molecule of pERK in BLA-NAc neurons during context-induced retrieval of morphine withdrawal memory; (4) D1 receptors also strengthened AMPA receptors, but not NMDA receptors, -mediated glutamatergic input to BLA-NAc neurons via pERK during context-induced retrieval of morphine withdrawal memory. These results suggest that different projection neurons of the BLA participate in the retrieval of morphine withdrawal memory with diverse molecular pathways.
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Complexo Nuclear Basolateral da Amígdala , Morfina , Neurônios , Núcleo Accumbens , Síndrome de Abstinência a Substâncias , Animais , Complexo Nuclear Basolateral da Amígdala/metabolismo , Masculino , Síndrome de Abstinência a Substâncias/metabolismo , Síndrome de Abstinência a Substâncias/fisiopatologia , Morfina/farmacologia , Neurônios/metabolismo , Núcleo Accumbens/metabolismo , Memória/fisiologia , Receptores de AMPA/metabolismo , Ratos , Dependência de Morfina/metabolismo , Tonsila do Cerebelo/metabolismo , Ratos Sprague-Dawley , Receptores de Dopamina D1/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Vias Neurais/metabolismo , Córtex Pré-Frontal/metabolismoRESUMO
Chronic morphine withdrawal memory formation is a complex process influenced by various molecular mechanisms. In this study, we aimed to investigate the contributions of the basolateral amygdala (BLA) and complement component 1, q subcomponent-like 3 (C1QL3), a secreted and presynaptically targeted protein, to the formation of chronic morphine (repeat dosing of morphine) withdrawal memory using conditioned place aversion (CPA) and chemogenetic methods. We conducted experiments involving the inhibition of the BLA during naloxone-induced withdrawal to assess its impact on CPA scores, providing insights into the significance of the BLA in the chronic morphine memory formation process. We also examined changes in C1ql3/C1QL3 expression within the BLA following conditioning. Immunofluorescence analysis revealed the colocalization of C1QL3 and the G protein-coupled receptor, brain-specific angiogenesis inhibitor 3 (BAI3) in the BLA, supporting their involvement in synaptic development. Moreover, we downregulated C1QL3 expression in the BLA to investigate its role in chronic morphine withdrawal memory formation. Our findings revealed that BLA inhibition during naloxone-induced withdrawal led to a significant reduction in CPA scores, confirming the critical role of the BLA in this memory process. Additionally, the upregulation of C1ql3 expression within the BLA postconditioning suggested its participation in withdrawal memory formation. The colocalization of C1QL3 and BAI3 in the BLA further supported their involvement in synaptic development. Furthermore, downregulation of C1QL3 in the BLA effectively hindered chronic morphine withdrawal memory formation, emphasizing its pivotal role in this process. Notably, we identified postsynaptic density protein 95 (PSD95) as a potential downstream effector of C1QL3 during chronic morphine withdrawal memory formation. Blocking PSD95 led to a significant reduction in the CPA score, and it appeared that C1QL3 modulated the ubiquitination-mediated degradation of PSD95, resulting in decreased PSD95 protein levels. This study underscores the importance of the BLA, C1QL3 and PSD95 in chronic morphine withdrawal memory formation. It provides valuable insights into the underlying molecular mechanisms, emphasizing their significance in this intricate process.
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Complexo Nuclear Basolateral da Amígdala , Proteína 4 Homóloga a Disks-Large , Memória , Morfina , Síndrome de Abstinência a Substâncias , Animais , Morfina/farmacologia , Síndrome de Abstinência a Substâncias/metabolismo , Masculino , Camundongos , Memória/efeitos dos fármacos , Proteína 4 Homóloga a Disks-Large/metabolismo , Complexo Nuclear Basolateral da Amígdala/metabolismo , Complexo Nuclear Basolateral da Amígdala/efeitos dos fármacos , Complemento C1q/metabolismo , Camundongos Endogâmicos C57BL , Naloxona/farmacologiaRESUMO
Addiction to morphine is a chronic brain disease leading to compulsive abuse. Drug addiction animal models with and without conditioned place preference (CPP) training have been used to investigate cue-elicited drug craving. We used 18 F-fluorodeoxyglucose (18 F-FDG) and 11 C-2-ß-carbomethoxy-3-ß-(4-fluorophenyl)tropane (11 C-CFT) micro-PET/CT scans to examine the regional changes in brain glucose metabolism and dopamine transporter (DAT) availability to study their relationship underlying drug memory in morphine-treated rat models with and without CPP. Standardized uptake value ratio (SUVr) of 18 F-FDG significantly decreased in the medial prefrontal cortex (mPFC) and cingulate with short-term morphine administration compared with the baseline condition. Voxelwise analysis indicated glucose metabolism alterations in the somatosensory cortex, hippocampus and cingulate in morphine-treated rats and in the striatum, thalamus, medial prefrontal cortex, primary motor cortex and many regions in the cortex in the CPP group compared with the baseline condition. Alterative glucose metabolism was also observed in the striatum, primary somatosensory cortex and some cortical regions in the CPP group compared with morphine alone group. DAT expression alterations were only observed in the long-term morphine compared with the short-term morphine group. This study shows that cerebral glucose metabolism significantly altered during morphine administration and CPP process mainly in the mPFC, striatum and hippocampus, which indicates that the function of these brain regions is involved in cue-induced craving and memory retrieval.
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Proteínas da Membrana Plasmática de Transporte de Dopamina , Morfina , Animais , Ratos , Encéfalo/diagnóstico por imagem , Fluordesoxiglucose F18 , Glucose , Morfina/farmacologia , Tomografia por Emissão de Pósitrons combinada à Tomografia ComputadorizadaRESUMO
The process through which early memories are transferred to the cerebral cortex to form long-term memories is referred to as memory consolidation, and the basolateral amygdala (BLA) is an important brain region involved in this process. Although functional connections between the BLA and multiple brain regions are critical for the consolidation of withdrawal memory, whether the projection from the BLA to the anterior cingulate cortex (ACC) is involved in the formation or consolidation of withdrawal memory remains unclear. In this paper, we used a chemical genetic method to specifically label the BLA-ACC projection in a combined morphine withdrawal and conditioned place aversion (CPA) animal model. We found that (1) the inhibition of the BLA-ACC projection during conditioning had no effects on the formation of early withdrawal memory; (2) the inhibition of the BLA-ACC projection had no effects on the retrieval of either early or long-term withdrawal memory; and (3) the persistent inhibition of the BLA-ACC projection after early withdrawal memory formation could inhibit the formation of long-term withdrawal memory and decrease Arc protein expression in the ACC. These results suggested that the persistent activation of the BLA-ACC projection after the formation of early withdrawal memory facilitates the formation of long-term withdrawal memory by increasing the plasticity of ACC neurons.
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Complexo Nuclear Basolateral da Amígdala/efeitos dos fármacos , Giro do Cíngulo/efeitos dos fármacos , Consolidação da Memória/efeitos dos fármacos , Morfina/farmacologia , Transtornos Relacionados com Narcóticos/fisiopatologia , Animais , Giro do Cíngulo/metabolismo , Masculino , Consolidação da Memória/fisiologia , Memória de Longo Prazo/fisiologia , Camundongos , Camundongos Endogâmicos C57BLRESUMO
An unprecedented use of N-hydroxy sulfonamides as sulfenylating agents has been established. In the presence of catalytic amounts of iodine and N-hydroxysuccinimide, N-hydroxy sulfonamides participated in sulfenylation with indoles, 7-azaindole, N-methyl pyrrole, and 2-naphthol to afford structurally diverse thioethers in moderate to excellent yields with very high regioselectivity.
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The study aims to evaluate the bioequivalence of valsartan hydrochlorothiazide tablets, and to investigate the potential cause of bioinequivalence. This was a single-center study with an open, randomized double-way crossover design. Test and reference preparations containing 160 mg of valsartan and 25 mg of hydrochlorothiazide were given to 36 healthy male volunteers. Plasma concentrations of valsartan and hydrochlorothiazide were determined simultaneously by LC-MS/MS. The pharmacokinetic parameters and relative bioavailability were calculated, while the bioequivalence between test and reference preparations were evaluated. The dissolution profiles of test and reference preparations in four different mediums were determined via dissolution test and HPLC. The similarity was investigated according to the similarity factors (f2). The F(o-t) and F(0-infinity) were (139.4 +/- 65.2)% and (137.5 +/- 61.2)% for valsartan of test preparations. It led to get the conclusion that test and reference preparations were not bioequivalent for valsartan. A significant difference was observed between test and reference tablets in the valsartan dissolution test of pH 1.2 hydrochloric acid solution. The key factor of the bioinequivalence might be that dissolution of valsartan in acid medium has marked difference between two preparations.
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Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacocinética , Anti-Hipertensivos/farmacocinética , Valsartana/farmacocinética , Administração Oral , Adolescente , Adulto , Bloqueadores do Receptor Tipo 1 de Angiotensina II/administração & dosagem , Bloqueadores do Receptor Tipo 1 de Angiotensina II/efeitos adversos , Bloqueadores do Receptor Tipo 1 de Angiotensina II/sangue , Anti-Hipertensivos/administração & dosagem , Anti-Hipertensivos/efeitos adversos , Anti-Hipertensivos/sangue , Área Sob a Curva , Cromatografia Líquida , Estudos Cross-Over , Liberação Controlada de Fármacos , Humanos , Hidroclorotiazida/administração & dosagem , Hidroclorotiazida/efeitos adversos , Hidroclorotiazida/sangue , Hidroclorotiazida/farmacocinética , Masculino , Comprimidos , Espectrometria de Massas em Tandem , Equivalência Terapêutica , Valsartana/administração & dosagem , Valsartana/efeitos adversos , Valsartana/sangue , Adulto JovemRESUMO
The medial entorhinal cortex (MEC) is crucial for contextual memory, yet its role in context-induced retrieval of morphine withdrawal memory remains unclear. This study investigated the role of the MEC and its projection neurons from MEC layer 5 to the basolateral amygdala (BLA) (MEC-BLA neurons) in context-induced retrieval of morphine withdrawal memory. Results show that context activates the MEC in morphine withdrawal mice, and the inactivation of the MEC inhibits context-induced retrieval of morphine withdrawal memory. At neural circuits, context activates MEC-BLA neurons in morphine withdrawal mice, and the inactivation of MEC-BLA neurons inhibits context-induced retrieval of morphine withdrawal memory. But MEC-BLA neurons are not activated by conditioning of context and morphine withdrawal, and the inhibition of MEC-BLA neurons do not influence the coupling of context and morphine withdrawal memory. These results suggest that MEC-BLA neurons are critical for the retrieval, but not for the formation, of morphine withdrawal memory.
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Pueraria montana var. lobata (P. lobata) is a traditional medicinal plant belonging to the Pueraria genus of Fabaceae family. Pueraria montana var. thomsonii (P. thomsonii) and Pueraria montana var. montana (P. montana) are its related species. However, evolutionary history of the Pueraria genus is still largely unknown. Here, a high-integrity, chromosome-level genome of P. lobata and an improved genome of P. thomsonii were reported. It found evidence for an ancient whole-genome triplication and a recent whole-genome duplication shared with Fabaceae in three Pueraria species. Population genomics of 121 Pueraria accessions demonstrated that P. lobata populations had substantially higher genetic diversity, and P. thomsonii was probably derived from P. lobata by domestication as a subspecies. Selection sweep analysis identified candidate genes in P. thomsonii populations associated with the synthesis of auxin and gibberellin, which potentially play a role in the expansion and starch accumulation of tubers in P. thomsonii. Overall, the findings provide new insights into the evolutionary and domestication history of the Pueraria genome and offer a valuable genomic resource for the genetic improvement of these species.
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Variação Genética , Genoma de Planta , Pueraria , Pueraria/genética , Filogenia , Evolução MolecularRESUMO
Sirtuin 1 (SIRT1) is one member of the silent information regulator 2 (Sir2)-like family of proteins involved in glucose homeostasis in mammals. It has been reported that SIRT1 modulates endocrine signaling of glucose and fat homeostasis by regulating transcription factors such as forkhead transcription factor 3a (FOXO3a), glucose transporter 4 (GLUT4), peroxisome proliferator-activated receptor gamma (PPARγ) and PPARγ coactivator (PGC-1α). However, it is still not clear how SIRT1 is involved in the development of insulin resistance. To determine the location and expression of SIRT1 and its target proteins in rats and analyze the interactions and functions of these proteins in insulin resistance. Forty-eight male Sprague-Dawley rats were randomly divided into four regimen groups: normal control (NC), calorie restriction (CR), high-fat (HFa), and high-fructose (HFr). Animals were fed for 12 weeks and blood samples collected from tail veins at weeks 2, 4, 6, 8 and 12 after fasting for 16 h. Baseline metabolic parameters such as fasting blood sugar, insulin, cholesterol and triglycerides were analyzed. A glucose tolerance test was carried out at the end of the study. Visceral fat, consisting of epididymis and perirenal fat, was isolated and weighed. The pancreas from each animal was also immediately removed. Immunohistochemical staining was performed to detect the locations of SIRT1, FOXO3a, GLUT4, PPARγ and PGC-1α in the ß-cell of the rat pancreas. Expression in the pancreas was analyzed by western blotting. Blood biochemical analysis indicated that the HFa and HFr groups were insulin-resistant. Immunohistochemical staining showed that GLUT4 was a nuclear protein. SIRT1, FOXO3a, PPARγ and PGC-1α were present in both the nucleus and the cytoplasm of ß-cells of pancreatic islets. The expression of SIRT1, GLUT4 and PGC-1α increased significantly in response to CR, but decreased in the HFr and HFa groups. FOXO3a was similar in the CR and the NC groups, whereas it declined in the HFa and HFr groups. PPARγ was elevated in the HFa group, but dropped in the CR and HFr groups. These data suggest that SIRT1 and its regulators are involved in the development of insulin resistance.
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Fatores de Transcrição Forkhead/metabolismo , Transportador de Glucose Tipo 4/metabolismo , Resistência à Insulina/genética , PPAR gama/metabolismo , Proteínas de Ligação a RNA/metabolismo , Sirtuína 1/metabolismo , Fatores de Transcrição/metabolismo , Animais , Restrição Calórica , Dieta Hiperlipídica , Proteína Forkhead Box O3 , Frutose/administração & dosagem , Regulação da Expressão Gênica/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/ultraestrutura , Masculino , Pâncreas/citologia , Pâncreas/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Ligação Proteica , Ratos , Ratos Sprague-DawleyRESUMO
OBJECTIVE: To investigate the current situation and influential factors of blood pressure (BP) control in type 2 diabetic patients with overweight or obesity in Guangdong province. METHODS: From August 2011 to March 2012, type 2 diabetic patients with overweight or obesity were recruited from 60 hospitals in 20 cities of Guangdong province, and received standard questionnaires. The conditions of demographic data, clinical examinations, the most recent laboratory assessment, history of disease and drug therapy were recorded. RESULTS: A total of 4029 patients were collected with age of (58.9 ± 12.9) years, and body mass index (BMI) of (27.28 ± 2.76) kg/m². Among the participants, controlled BP was achieved in 23.8% patients. Multiple logistic regression analysis showed that older age, obesity, previous history of hypertension and inadequate glycemic control were the independent factors related to unsatisfactory blood pressure control rate. Among the patients with hypertension, 53.5% took 1 kind of antihypertensive drug, 32.5% took two, and 11.3% took three or more. CONCLUSIONS: Type 2 diabetic patients with overweight or obesity in Guangdong province have poor BP control. Thus, active lifestyle interventions and drug therapy as a comprehensive management way should be taken for the population so as to reduce their cardiovascular events.
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Pressão Sanguínea , Diabetes Mellitus Tipo 2/fisiopatologia , Hipertensão/prevenção & controle , Obesidade/fisiopatologia , Sobrepeso/fisiopatologia , Adulto , Idoso , Estudos Transversais , Diabetes Mellitus Tipo 2/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/complicações , Sobrepeso/complicações , Fatores de Risco , Inquéritos e QuestionáriosRESUMO
OBJECTIVE: To explore the prevalence and risk factors for dyslipidemia in diabetics with overweight or obesity. METHODS: Diabetics with overweight or obesity were recruited from 62 tertiary and secondary hospitals in Guangdong Province between August 2011 and March 2012. Dyslipidemia was diagnosed as total cholesterol (TC) ≥ 5.7 mmol/L or triglycerides (TG) ≥ 1.7 mmol/L or low-density-lipoprotein cholesterol (LDL-C) ≥ 3.6 mmol/L or high-density-lipoprotein cholesterol (HDL-C) < 1.29 mmol/L in females or HDL-C < 1.03 mmol/L in males. Binary Logistic regression was used to assess the associations between dyslipidemia and associated risk factors. RESULTS: Dyslipidemia was detected in 3160/3593 (87.9%) diabetics with overweight or obesity. And the prevalence of hypertriglyceridemia, low blood HDL-C, hypercholesterolemia and high blood LDL-C was 52.5% (1888/3593) , 54.1% (1945/3593), 33.1% (1188/3593) and 27.4% (985/3593) respectively. Among those with dyslipidemia, patients with simple and mixed dyslipidemia accounted for 34.1% and 53.9% respectively. In binary Logistic regression analysis, the presence of dyslipidemia were associated with female gender (OR = 1.593, 95%CI 1.233-2.057), hemoglobinA1c(HbA1c) (OR = 1.120, 95%CI 1.054-1.191), body mass index (OR = 1.084, 95%CI 1.022-1.150), hypertension (OR = 1.331, 95%CI 1.033-1.714), history of diabetes (OR = 1.586, 95%CI 1.186-2.120) and hyperuricacidemia (OR = 2.270, 95%CI 1.642-3.138). CONCLUSIONS: The prevalence of dyslipidemia is quite high in diabetics with overweight or obesity. The controls of blood pressure, serum uric acid level, blood glucose and body weight may reduce the prevalence of dyslipidemia, prevent and delay the development of cardiovascular complications and reduce the mortality of diabetics with overweight or obesity.
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Diabetes Mellitus Tipo 2/epidemiologia , Hiperlipidemias/epidemiologia , Obesidade/epidemiologia , Sobrepeso/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , China/epidemiologia , Feminino , Humanos , Hipercolesterolemia/epidemiologia , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Adulto JovemRESUMO
OBJECTIVE: To explore the glycemic control status and related risk factors of overweight or obesity patients with type 2 diabetes mellitus (T2DM) in Guangdong province. METHODS: The medical records of overweight or obesity patients with T2DM from 60 tertiary and secondary hospitals in Guangdong Province were collected by questionnaire and physical examination. And the clinical data were analyzed to explore the influencing factors of glycemic control. The HbA1c level was used to assess glycemic control. HbA1c < 7.0% indicated that glycemic control was up to standard. RESULTS: From August 2011 to March 2012, 5241 T2DM patients were recruited. The scope of current analysis was restricted to 4768 subjects with true data and deficiency no more than 5%. There were 2252 males and 2516 females. The age range was from 16 to 90 years, a median age 59.0 (50.0 - 69.0) years, onset age of diabetes 52.0 (44.0 - 60.0) years; a range of disease duration from 1 day to 42 years and a median of 5.0 (2.0 - 11.0) years. The median body mass index was 26.33(24.88 - 28.34) kg/m(2) and median waist circumference 93.0 (88.0 - 100.0) cm. Median HbA1c was 8.1% (6.9% - 10.1%) and only 26.2% patients reached the target level of HbA1c < 7.0%. Influencing factors of poor glycemic control were central obesity, high levels of resting heart rate, concurrent fatty liver and high intensity of treatment. And influencing factors of good glycemic control were regular exercises, smoking cessation, regular glycemic monitoring and good control of total cholesterol/triglyceride. CONCLUSION: A majority of Guangdong type 2 diabetics fail to achieve target values for glycemic control. There is an urgent need for comprehensive management for improving glycemic control.
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Diabetes Mellitus Tipo 2/epidemiologia , Obesidade/epidemiologia , Sobrepeso/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Glicemia/metabolismo , China/epidemiologia , Estudos Transversais , Diabetes Mellitus Tipo 2/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/sangue , Sobrepeso/sangue , Prevalência , Fatores de Risco , Adulto JovemRESUMO
An unprecedented hydride transfer-triggered cross-dehydrogenative coupling of two C(sp3)-H bonds to target nine-membered rings has been developed. Salient features of this methodology include atom and step economy and metal-free and redox-neutral conditions, with water as the byproduct and proceeding well even with decomposed aldehydes.
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The lateral hypothalamus (LH) is physiologically critical in brain functions. The LH also plays an important role in drug addiction. However, neural circuits underlying LH involvement of drug addiction remain obscure. In the present study,our results showed that in male mice, during context-induced expression of morphine withdrawal memory, LH glutamatergic neurons played an important role; dopamine D1 receptor-expressing medium spiny neurons (D1-MSNs) projecting from the core of nucleus accumbens (NAcC) to the LH were an important upstream circuit to activate LH glutamatergic neurons; D1-MSNs projecting from the NAcC to the LH activated LH glutamatergic neurons through inhibiting LH local gamma-aminobutyric acid (GABA) neurons. These results suggest that disinhibited LH glutamatergic neurons by neural circuits from the NAcC importantly contribute to context-induced the expression of morphine withdrawal memory.
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Morfina , Transtornos Relacionados ao Uso de Substâncias , Camundongos , Masculino , Animais , Morfina/efeitos adversos , Núcleo Accumbens/metabolismo , Região Hipotalâmica Lateral/metabolismo , Neurônios/metabolismo , Receptores de Dopamina D1/metabolismo , Transtornos Relacionados ao Uso de Substâncias/metabolismoRESUMO
OBJECTIVE: To investigate the glycemic control and the related factors of type 1 diabetic patients in Guangdong Province. METHODS: Medical records and blood samples of type 1 diabetic patients were collected in 89 tertiary and secondary hospitals from all of the 21 cities in Guangdong Province. The clinical data were analyzed to explore the correlates of glycemic control. HbA1c levels, measured in Guangdong Diabetes Center, were used to assess glycemic control. RESULTS: 851 patients were enrolled from August 6, 2010 to May 25, 2011. There were 408 males and 443 females. The median (interquartile range) age was 29.6 years (20.3 - 41.3 years). The onset age of diabetes was 25.3 years (15.7 - 35.5 years). The disease duration was 3.3 years (1.0 - 7.3 years). The BMI was 19.9 kg/m(2) (17.9 - 21.8 kg/m(2)). HbA1c levels were 8.6% (6.9% - 11.0%) and only 234 (27.50%) patients reached the age-specific target levels. Correlates with poorer glycemic control were 13 - 19 years old (vs 7 - 12 and ≥ 20 years old), lower household income, not on dietary intervention, never accepting diabetic education and shorter diabetic duration. CONCLUSION: The majority of Guangdong type 1 diabetic patients did not achieve target values for glycemic control, indicating an urgent need for comprehensive management to improve glycemic control.
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Diabetes Mellitus Tipo 1/epidemiologia , Diabetes Mellitus Tipo 1/prevenção & controle , Adolescente , Adulto , Idade de Início , Glicemia , China/epidemiologia , Estudos Transversais , Diabetes Mellitus Tipo 1/sangue , Feminino , Hemoglobinas Glicadas , Humanos , Masculino , Adulto JovemRESUMO
Rac1 is a small GTPase of the Rho family. A previous study showed that the activation of Rac1 had an opposing effect on induction and maintenance of long-term potentiation (LTP) in the hippocampus. However, the molecular mechanism underlying this opposing effect remains to be addressed. In the present work, we find that the activation of Rac1 during the induction of LTP leads to an activation of PKCι/λ by phosphatidylinositol-3-kinase (PI3K), whereas the activation of Rac1 during the maintenance of LTP leads to the inhibition of PKMζ by LIM_kinase (LIMK) in the hippocampus. This result suggests that during different stages of LTP, the activation of Rac1 can modulate different signaling pathways, which leads to an opposing effect on the induction and maintenance of LTP in the hippocampus.
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BACKGROUND: Accumulating evidence indicates that neuroinflammation (NI) significantly contributes to drug addiction, but the conversion of NI after drug withdrawal is not clear. Here, we conducted 18F-flutriciclamide (GE180) positron emission tomography (PET) imaging to investigate the conversion of NI during drug withdrawal and conditioning-induced aversion by measuring the change in microglial activation with 18F-GE180. METHODS: Twelve male adult Sprague-Dawley rats were subjected to morphine withdrawal by the administration of naloxone, and six of them were used to model conditioned place aversion (CPA). 18F-GE180 PET imaging was performed for 11 rats on the last day of the morphine treatment phase and for 10 rats on the response assessment phase of the behavior conditioning procedure. A 18F-GE180 template was established for spatial normalization of each individual image, and the differential 18F-GE180 uptakes between the drug withdrawal (DW) group and the drug addiction (DA) group, the CPA group and the DA group, and the CPA group and the DW group were compared by a voxel-wise two-sample t test using SPM8. RESULTS: Both the DW group and the CPA group spent less time in the conditioning cage during the post-test phase compared with the pretest phase, but only the difference in the CPA group was significant (63.2 ± 34.6 vs. - 159.53 ± 22.02, P < 0.005). Compared with the DA group, the uptake of 18F-GE180 increased mainly in the hippocampus, visual cortex, thalamus and midbrain regions and decreased mainly in the sensory-related cortices after the administration of naloxone in both the DW and CPA groups. Increased 18F-GE180 uptake was only observed in the mesolimbic regions after conditioned aversion compared with the DW group. CONCLUSION: In morphine-dependent rats, Neuroinflammation (NI) became more severe in the addiction-involved brain regions but remitted in the sensory-related brain regions after the administration of naloxone, and this NI induced by withdrawal was further aggravated after conditioned aversion formation thus may help to consolidate the withdrawal memory.
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The El Niño-Southern Oscillation (ENSO) is the principal climatic system in the modern Pacific Ocean, and it potentially influences the global climate. The South China Sea (SCS), in the western tropical Pacific, is significantly affected by ENSO activity. We have conducted a high-resolution oxygen isotope study of the shells of one modern and four fossil Tridacna from the Xisha Islands in the SCS. The results for the modern sample reveal that the shells of Tridacna are a good proxy of ENSO variability. We used the results of the oxygen isotope composition of four fossil Tridacna to produce high-resolution records of ENSO activity during four time slices in the Holocene. The results indicate that ENSO variability in the early Holocene was comparable to that of today, and that a minimum in the frequency and intensity of ENSO activity occurred in the mid Holocene. These findings are consistent with paleoclimatic results from corals, mollusks and sedimentary records. However, the observed extremely low frequency and moderate ENSO intensity at 4.7 ka indicate an anomalous pattern of ENSO changes within this interval of climatic transition. In addition, seasonal temperature variations during the Holocene were different from those of today and extreme seasonality may also occur during warmer periods.
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Ventral tegmental area (VTA) dopamine (DA) neurons presynaptic glutamate release plays a very important role in the mechanism of morphine. Previously, a study from our lab found that morphine disinhibited glutamatergic input onto the VTA-DA neurons, which was an important mechanism for the morphine-induced increase in the VTA-DA neuron firing and related behaviors (Chen et al., 2015). However, what source of glutamatergic inputs is disinhibited by morphine remains to be elucidated. Using optogenetic strategy combined with whole-cell patch-clamp, qRT-PCR, immunofluorescence and chemical genetic approach combined with behavioral methods, our results show that: 1) morphine promotes glutamate release from glutamatergic terminals of medial prefrontal cortex (mPFC) neurons projecting to VTA-DA neurons but does not on those from glutamatergic terminals of the lateral hypothalamus (LH) neurons projecting to VTA-DA neurons; 2) different response of glutamatergic neurons projecting to VTA-DA neurons from the mPFC or the LH to morphine is related to the expression of GABAB receptors at terminals of these neurons; 3) inhibition of projection neurons from the mPFC to the VTA significantly reduces morphine-induced locomotor activity increase and conditioned place preference but inhibition of projection neurons from the LH to the VTA does not. These results suggest that morphine selectively promotes glutamate release of the glutamatergic input from mPFC onto VTA-DA neurons by removing the inhibition of the GABAB receptors in this glutamatergic input from mPFC.
Assuntos
Neurônios Dopaminérgicos/metabolismo , Ácido Glutâmico/metabolismo , Morfina/administração & dosagem , Córtex Pré-Frontal/metabolismo , Recompensa , Área Tegmentar Ventral/metabolismo , Analgésicos Opioides/administração & dosagem , Animais , Neurônios Dopaminérgicos/química , Neurônios Dopaminérgicos/efeitos dos fármacos , Ácido Glutâmico/análise , Injeções Intraventriculares , Locomoção/efeitos dos fármacos , Locomoção/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Técnicas de Cultura de Órgãos , Córtex Pré-Frontal/química , Córtex Pré-Frontal/efeitos dos fármacos , Área Tegmentar Ventral/química , Área Tegmentar Ventral/efeitos dos fármacosRESUMO
Conditioned context-induced retrieval of drug withdrawal memory contributes to drug relapse. The basolateral amygdala (BLA) is an important brain region that is involved in conditioned context-induced retrieval of morphine withdrawal memory. However, the upstream pathways of the activation of the BLA by conditioned context remains to be studied. The present results show that the CA1 of dorsal hippocampus is an upstream brain region of the activation of the BLA during conditioned context-induced morphine withdrawal memory retrieval; the indirect connection from the CA1 of dorsal hippocampus to the BLA is enhanced in mice with conditioned place aversion (CPA); the postrhinal cortex (POR) is a brain region that connects the CA1 of dorsal hippocampus and the activation of the BLA during conditioned context-induced retrieval of morphine-withdrawal memory. These results suggest that a conditioning-strengthened indirect circuit from the CA1 of dorsal hippocampus to the BLA through the POR participates in morphine withdrawal memory retrieval.