DA Content Research Articles

L-linalool exerts a neuroprotective action on hemiparkinsonian rats.

Linalool (LIN) is a monoterpene, responsible for the aroma of essential oils in some species. It presents a sedative and anxiolytic potential, enhancing GABAergic currents and behaving as a benzodiazepine-type of drug. The objectives of the present work were to study the neuroprotective effects of LIN on a model of Parkinson's disease. For that, male Wistar rats were divided into the following groups: sham-operated (SO), 6-OHDA-lesioned, and 6-OHDA-lesioned and treated with LIN (25, 50, and 100mg/kg, p.o.) for 2weeks. Afterwards, the animals were subjected to behavioral tests (apomorphine-induced rotations, open field, and forced swimming tests). Then, the animals were euthanized, and the striatum, hippocampus, and prefrontal cortex were processed for neurochemistry (nitrite and lipoperoxidation measurements) and immunohistochemistry (TH and DAT) assays. The results were analyzed by ANOVA and Tukey's test for multiple comparisons and considered significant at p < 0.05. LIN significantly improved the behavioral alterations of the 6-OHDA-lesioned group, as evaluated by the apomorphine-induced rotations, open field, and forced swimming tests. In addition, LIN partially reversed the decreased DA, DOPAC, and HVA contents observed in the 6-OHDA-lesioned striatum. The untreated 6-OHDA group presented increased nitrite contents and lipoperoxidation in all the brain areas studied, and these changes were completely reversed after LIN treatments. Finally, LIN significantly prevented the reduction in TH and DAT expressions demonstrated in the right 6-OHDA-lesioned striatum. All these data strongly suggest that LIN presents a neuroprotective action in hemiparkinsonian rats, probably related to the drug anti-inflammatory and antioxidant activities.

Neurorestorative effects of sub-chronic administration of ambroxol in rodent model of Parkinson's disease.

Disease-modifying agents are unmet medical need for Parkinson's disease (PD). Drugs are under clinical trial to halt its progression, such as ambroxol due to its glucocerebrosidase (GCase)-stimulating activity. However, the neurorestorative effect of ambroxol is not yet investigated in any of the well-established PD models in vivo. Ambroxol was administered as 400 mg/kg orally twice a day from D-28 to D-70 after the unilateral intrastriatal injection of 6-hydroxydopamine (6-OHDA) in male rats. Behavioral parameters were observed every week, and at last, tyrosine hydroxylase (TH), dopamine transporter (DAT), glucocerbrosidase (GCase) enzymatic and mitochondrial complex-I activity, α-synuclein levels, and Nissl's staining were performed. Behavioral functions were progressively recovered. Ambroxol restored TH and DAT levels on D-71 as the markers of dopaminergic cell and extracellular DA concentration respectively, indicating the recovery of dopaminergic system. Factors involved in PD pathogenesis such as GCase enzymatic and mitochondrial complex-I activity were restored, and α-synuclein pathology was decreased by ambroxol. GCase deficiency is involved in mitochondrial impairment and formation of oligomeric α-synuclein aggregates which negatively affect mitochondrial function. Nissl bodies were also normalized. Therefore, both the GCase-stimulating and α-synuclein pathology-diminishing effects of ambroxol may be responsible for increment in mitochondrial function and restoration of dopaminergic system. These may act as significant mechanisms for disease-modifying potential of ambroxol. The current study provides the preclinical evidence to support the neurorestorative potential of ambroxol in 6-OHDA-induced hemiparkinson's rat model and indicates its possible use as disease-modifying agent in PD.

Oridonin, A natural diterpenoid, protected NGF-differentiated PC12 cells against MPP+- and kainic acid-induced injury

Oridonin (ORI) is a natural diterpenoid presented in some medicinal plants. The effects of pre-treatments from ORI against MPP+- or kainic acid (KA)-induced damage in nerve growth factor (NGF)-differentiated PC12 cells were investigated. Results showed that pre-treatments of ORI at 0.25–2 μM enhanced the viability and plasma membrane integrity of NGF-differentiated PC12 cells. MPP+ or KA exposure down-regulated Bcl-2 mRNA expression, up-regulated Bax mRNA expression, increased caspase-3 activity and decreased Na+-K+ ATPase activity. ORI pre-treatments at test concentrations reversed these changes. ORI pre-treatments decreased reactive oxygen species production, raised glutathione level, and increased glutathione peroxidase, glutathione reductase and catalase activities in MPP+ or KA treated cells. ORI pre-treatments lowered tumor necrosis factor-alpha, interleukin (IL)-1beta, IL-6 and prostaglandin E2 levels in MPP+ or KA treated cells. ORI also diminished MPP+ or KA induced increase in nuclear factor-κB binding activity. MPP+ exposure suppressed tyrosine hydroxylase (TH) mRNA expression and decreased dopamine content. KA exposure reduced glutamine synthetase (GS) mRNA expression, raised glutamate level and lowered glutamine level. ORI pre-treatments at 0.5–2 μM up-regulated mRNA expression of TH and GS, restored DA and glutamine content. These findings suggested that oridonin was a potent neuro-protective agent against Parkinson's disease and seizure.

Strengths and limitations of morphological and behavioral analyses in detecting dopaminergic deficiency in Caenorhabditis elegans

In order to develop a better understanding of the role environmental toxicants may play in the onset and progression of neurodegenerative diseases, it has become increasingly important to optimize sensitive methods for quickly screening toxicants to determine their ability to disrupt neuronal function. The nematode Caenorhabditis elegans can help with this effort. This species has an integrated nervous system producing behavioral function, provides easy access for molecular studies, has a rapid lifespan, and is an inexpensive model. This study focuses on methods of measuring neurodegeneration involving the dopaminergic system and the identification of compounds with actions that disrupt dopamine function in the model organism C. elegans. Several dopamine-mediated locomotory behaviors, Area Exploration, Body Bends, and Reversals, as well as Swimming-Induced Paralysis and Learned 2-Nonanone Avoidance, were compared to determine the best behavioral method for screening purposes. These behavioral endpoints were also compared to morphological scoring of neurodegeneration in the dopamine neurons. We found that in adult worms, Area Exploration is more advantageous than the other behavioral methods for identifying DA-deficient locomotion and is comparable to neuromorphological scoring outputs. For larval stage worms, locomotion was an unreliable endpoint, and neuronal scoring appeared to be the best method. We compared the wild-type N2 strain to the commonly used dat-1p::GFP reporter strains BY200 and BZ555, and we further characterized the dopamine-deficient strains, cat-2 e1112 and cat-2 n4547. In contrast to published results, we found that the cat-2 strains slowed on food almost as much as N2s. Both showed decreased levels of cat-2 mRNA and DA content, rather than none, with cat-2 e1112 having the greatest reduction in DA content in comparison to N2. Finally, we compared and contrasted strengths, limitations, cost, and equipment needs for all primary methods for analysis of the dopamine system in C. elegans.

Downregulation of lncRNA UCA1 ameliorates the damage of dopaminergic neurons, reduces oxidative stress and inflammation in Parkinson's disease through the inhibition of the PI3K/Akt signaling pathway

This study is conducted to investigate the role of lncRNA urothelial carcinoma-associated 1 (UCA1) in the protection of dopaminergic neurons in Parkinson's disease (PD) through regulating the PI3K/Akt signaling pathway. PD rat model was induced by injection of 6-hydroxydopamine (6-OHDA) to damage the substantia nigra striatum. The successfully modeled PD rats were introduced with siRNA-negative control (NC) or UCA1-siRNA. The expression of UCA1 in neurobehavioral change, neuroinflammatory response and oxidative stress of PD rats were explored. The effect of UCA1 on the PI3K/Akt signaling pathway and downstream proteins IκBα and ERK was also investigated. The rats with PD exhibited aggregated neurobehavioral change, increased neuroinflammatory response and oxidative stress. Down-regulation of UCA1 up-regulated the expression of TH positive cells and DA content, reduced the apoptosis of substantia nigra neurons, the apoptosis of substantia nigra neurons and oxidative stress and improved the neuroinflammatory response in PD rats. Down-regulation of UCA1 inhibited the activation of the PI3K/AKT signaling pathway in substantia nigra of PD rats. Our study suggests that the downregulated lncRNA UCA1 ameliorates the damage of dopaminergic neurons, reduces oxidative stress and inflammation in PD rats through the inhibition of the PI3K/Akt signaling pathway.

The development of the serotonergic and dopaminergic systems during chicken mid-late embryogenesis

Serotonin (5-HT) acts as a morphogen influencing embryonic brain development, and as a neurotransmitter regulating multiple biological functions with lifelong effects on animal physical, physiological and mental health, especially during the rapid growth phase prior to birth when embryos face many challenges to reach structural and functional completion. In this study, the development of the serotoninergic (5-HTergic) system and its modulatory effect on the dopaminergic (DAergic) system and related neural circuits were investigated during the mid-late embryogenesis, embryonic day (E)12-E20, in the chicken's brain. During 5-HTergic neuronal maturation, a growth-related anatomical and functional remodeling was highlighted: the 5-HT neurons continuously grew during E12-E20 except for a remarkable regression during E14-E16. Correspondingly, there was a time-dependent change in the 5-HT synthetic capacity. Specifically, 5-HT concentrations in the raphe nuclei increased from E12 to E14, reaching a first plateau during E14-E16, then continuously increased up to E19, and reaching a second plateau between E19-E20. The second plateau of the 5-HT concentration was in correspondence with the establishment of the 5-HTergic autoregulatory loop during E19-E20 and the development of the DAergic system. The DA concentrations remained unchanged from E12 to E16, then started to increase at E16, reaching a maximum at E19, and diminished before hatching. The unique developing time sequence between the 5-HTergic and DAergic systems suggests that the 5-HTergic system may play a critical role in forming the 5-HT – DA neural circuit during chicken embryogenesis. These results provide new insights for understanding the functional organization of the 5-HTergic system during embryonic development and raise the possibility that prenatally modulating the 5-HTergic system may lead to long-lasting brain structural and functional alterations.

(Invited) Using Fast Scan Cyclic Voltammetry to elucidate the mechanism of action of Deep Brain Stimulation

Deep Brain Stimulation (DBS) is now an established neurosurgical therapy for variety of neurologic and psychiatric disorders. Investigations into the mechanism of action of DBS, using electrochemical recording techniques such as Fast Scan Cyclic Voltammetry (FSCV), has now demonstrated that DBS evokes release of neurotransmitter, including dopamine and adenosine depending on sites of stimulation. FSCV has been an established method for investigating neurochemical changes in animal models and is emerging as a potential method for monitoring neurotransmitter systems in humans undergoing DBS. At the Mayo Clinic, we have developed the WINCS (Wireless Instantaneous Neurotransmitter Concentration Sensing) system and its successor WINCS-Harmoni, a next generation device capable of combining brain stimulation with real-time neurochemical recording in vivo. Recently, we have also developed a novel technique termed multiple cyclic square wave voltammetry (M-CSWV) for quantifying tonic DA concentrations in vivo, which uses cyclic square wave voltammetric waveforms in conjunction with a delayed holding potential period to control adsorption. Here, a review of the technology development of WINCS and the use FSCV for elucidating the mechanism of action of DBS will be presented.

Immunogenetic Characteristics of Trans-Baikal Different-Purpose Sheep

The results of the immunogenetic characteristics of Trans-Baikal breed fine-fleece sheep by six blood group systems, including fourteen antigen-specific factors, with respect to the production purposes have been reported. The performed analysis of the immunogenetic parameters of blood revealed similarity in the Bb, Bg, Ca, R, and O antigen-specific factors and remarkable differentiation in the Aa, Ab, Be, and Bi antigens between the wool-and-meat and meat-and-wool sheep. High frequencies of the Bb (0.980), Bi (0.873), Ca (0.932), Ma (0.555), R (0.538), and O (0.910) red blood-cell antigens are typical for the wool-and-meat sheep. The animals with antigens Bd, Be, Bg, and Mb (0.150, 0.278, 0.190, and 0.228, respectively) are rarely found. High concentrations of antigens Bb, Be, Ca, Ma, R, O, and Da (0.960, 0.743, 0.782, 0.812, 0.554, 0.713, and 0.505, respectively) are recorded in meat-and-wool sheep. Low frequencies in occurrence are recorded in the animal carriers of Aa (0.119), Ab (0.109), Bd (0.089), Bi (0.109), Bg (0.129), and Mb (0.149). The Aa, Ab, Bi, Ca, and O antigens are rather often found in the wool-and-meat sheep (P < 0.001), while the meat-and-wool sheep have higher concentrations of Be, Ma, and Da factors (P < 0.001). The genetic identity and distance between the intrabreed specimens comprised 0.652 and 0.428, respectively.

Structurally Similar and Behaviorally Unique Modafinil Analogs as Potential Pharmacotherapeutics for Psychostimulant Use Disorder

Modafinil has been used off‐label to treat psychostimulant use disorders (PSUD). However, its effectiveness in clinical trials seems limited to a subpopulation of subjects without concurrent alcohol or poly‐drug use. Since the main pharmacological target of cocaine is the dopamine transporter (DAT), recent efforts to develop more globally effective pharmacotherapies for PSUD have focused on two new DAT inhibitors and structural analogs of modafinil, JJC8‐088 and JJC8‐091, as promising lead compounds.In this study, the behavioral effects of these compounds were tested in rat models of cocaine self‐administration and reinstatement to drug seeking. Neurochemical correlates to those behaviors were assessed in microdialysis and fast‐scan cyclic voltammetry (FSCV) procedures aimed to measure extracellular dopamine levels and potential changes in dopamine dynamics in the nucleus accumbens shell (NAS).Our results show that JJC8‐088 (3, 10, 30 mg/kg, i.p.) dose‐dependently decreased the number of cocaine infusions under a fixed ratio schedule of self‐administration, while JJC8‐091 (10, 30, 56 mg/kg) failed to significantly alter cocaine self‐administration. In contrast, JJC8‐088 failed, while JJC8‐091 effectively decreased the break‐point for cocaine self‐administration under a progressive ratio schedule of behavior. JJC8‐088 maintained self‐administration behavior in both drug‐naïve and cocaine trained rats, while JJC8‐091 did not. Moreover, only priming injections of JJC8‐088 dose‐dependently reinstated drug‐seeking behavior in rats following previous cocaine extinction. Importantly, in the same rats, JJC8‐091 pretreatment blocked cocaine‐induced reinstatement of drug seeking behavior.The neurochemical assessment of JJC8‐088 and JJC8‐091 effects showed that both drugs dose‐dependently increased extracellular DA concentrations in dialysates from the NAS. However, JJC8‐088 was more potent and more efficacious in increasing DA levels compared to JJC8‐091. Indeed, the maximal changes in DA levels elicited by JJC8‐088 resemble those obtained with cocaine, in contrast to JJC8‐091.The FSCV studies showed that both JJC8‐088 and JJC8‐091 dose dependently reduced the rate of DA clearance, with JJC8‐088 producing effects greater in magnitude at lower doses than JJC8‐091. Finally, like cocaine, cumulative doses of JJC8‐088 produced a dose‐dependent increase in DAMax, while JJC8‐091 was ineffective at all doses tested.Collectively, these data show that despite sharing significant structural similarity, JJC8‐088 was cocaine‐like, while JJC8‐091 was not. Indeed, in contrast with JJC8‐088, JJC8‐091 did not elicit significant reinforcing actions and reduced or blunted the reinforcing effects of cocaine. Taken together, our data support further development of JJC8‐091, as a potential pharmacotherapy for the treatment of PSUD.Support or Funding InformationSupport for this research was provided by the Medication Development Program, National Institute on Drug Abuse ‐ Intramural Research Program, NIH/DHHSThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Translating the atypical dopamine uptake inhibitor hypothesis toward therapeutics for treatment of psychostimulant use disorders.

Medication-assisted treatments are unavailable to patients with cocaine use disorders. Efforts to develop potential pharmacotherapies have led to the identification of a promising lead molecule, JJC8-091, that demonstrates a novel binding mode at the dopamine transporter (DAT). Here, JJC8-091 and a structural analogue, JJC8-088, were extensively and comparatively assessed to elucidate neurochemical correlates to their divergent behavioral profiles. Despite sharing significant structural similarity, JJC8-088 was more cocaine-like, increasing extracellular DA concentrations in the nucleus accumbens shell (NAS) efficaciously and more potently than JJC8-091. In contrast, JJC8-091 was not self-administered and was effective in blocking cocaine-induced reinstatement to drug seeking. Electrophysiology experiments confirmed that JJC8-091 was more effective than JJC8-088 at inhibiting cocaine-mediated enhancement of DA neurotransmission. Further, when VTA DA neurons in DAT-cre mice were optically stimulated, JJC8-088 produced a significant leftward shift in the stimulation-response curve, similar to cocaine, while JJC8-091 shifted the curve downward, suggesting attenuation of DA-mediated brain reward. Computational models predicted that JJC8-088 binds in an outward facing conformation of DAT, similar to cocaine. Conversely, JJC8-091 steers DAT towards a more occluded conformation. Collectively, these data reveal the underlying molecular mechanism at DAT that may be leveraged to rationally optimize leads for the treatment of cocaine use disorders, with JJC8-091 representing a compelling candidate for development.

Effects of \u03b1-Synuclein Monomers Administration in the Gigantocellular Reticular Nucleus on Neurotransmission in Mouse Model

The aim of the study was to examine the Braak’s hypothesis to explain the spreading and distribution of the neuropathological changes observed in the course of Parkinson’s disease among ascending neuroanatomical regions. We investigated the neurotransmitter levels (monoamines and amino acid concentration) as well as tyrosine hydroxylase (TH) and transglutaminase-2 (TG2) mRNA expression in the mouse striata (ST) after intracerebral α-synuclein (ASN) administration into gigantocellular reticular nucleus (Gi). Male C57BL/10 Tar mice were used in this study. ASN was administrated by stereotactic injection into Gi area (4 μl; 1 μg/μl) and mice were decapitated after 1, 4 or 12 weeks post injection. The neurotransmitters concentration in ST were evaluated using HPLC detection. TH and TG2 mRNA expression were examined by Real-Time PCR method. At 4 and 12 weeks after ASN administration we observed decrease of DA concentration in ST relative to control groups and we found a significantly higher concentration one of the DA metabolites—DOPAC. At these time points, we also noticed the increase in DA turnover determined as DOPAC/DA ratio. Additionally, at 4 and 12 weeks after ASN injection we noted decreasing of TH mRNA expression. Our findings corresponds with the Braak’s theory about the presence of the first neuropathological changes within brainstem and then with time affecting higher neuroanatomical regions. These results obtained after administration of ASN monomers to the Gi area may be useful to explain the pathogenesis of Parkinson’s disease.

Ultrasensitive Reduced Graphene Oxide-Poly(Procion)/Gold Nanoparticles Modified Glassy Carbon Electrode for Selective and Simultaneous Determination of Ascorbic Acid, Dopamine, and Uric Acid

A highly ultrasensitive electrochemical sensor based on electrochemically reduced graphene oxide (ERGO), Procion Red MX-5B (PR) and gold nanoparticles (AuNPs) modified glassy carbon electrode (GCE) was developed. Cyclic voltammetry (CV) was employed to electropolymerize GO-PR mixture on GCE followed by deposition of AuNPs to obtain ERGO-poly(PR)/AuNPs/GCE. The physical properties of the nanocomposite were explored through field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FT-IR). The electrochemical performance of the ERGO-poly(PR)/AuNPs/GCE showed remarkable enhancement in the peak current toward oxidation of AA, DA, and UA with peak potentials separation of 0.21 V for AA-DA, and 0.15 V for DA-UA. Differential pulse voltammetry (DPV) was applied to perform individual and simultaneous analysis of the aforementioned analytes at optimized pH. DPV responses of AA, DA, and UA concentration were obtained over the range of 0.4–110, 0.4–170 and 0.4–150 μM with sensitivities of 0.48, 0.40, and 0.63 μA/μM (S/N = 3), respectively. Limit of detections for AA, DA, and UA were 54, 5.6 and 5.8 nM, respectively. Good repeatability, reproducibility as well as long-term stability were obtained. The developed modified electrode was used successfully to monitor AA, DA, and UA in vitamin C tablets, and human urine samples with favorable recoveries.

Human brain blood flow and metabolism during isocapnic hyperoxia: the role of reactive oxygen species.

It is unknown whether excessive reactive oxygen species (ROS) production drives the isocapnic hyperoxia (IH)-induced decline in human cerebral blood flow (CBF) via reduced nitric oxide (NO) bioavailability and leads to disruption of the blood-brain barrier (BBB) or neural-parenchymal damage. Cerebral metabolic rate for oxygen (CMR ) and transcerebral exchanges of NO end-products, oxidants, antioxidants and neural-parenchymal damage markers were simultaneously quantified under IH with intravenous saline and ascorbic acid infusion. CBF and were reduced during IH, responses that were followed by increased oxidative stress and reduced NO bioavailability when saline was infused. No indication of neural-parenchymal damage or disruption of the BBB was observed during IH. Antioxidant defences were increased during ascorbic acid infusion, while CBF, , oxidant and NO bioavailability markers remained unchanged. ROS play a role in the regulation of CBF and metabolism during IH without evidence of BBB disruption or neural-parenchymal damage. To test the hypothesis that isocapnic hyperoxia (IH) affects cerebral blood flow (CBF) and metabolism through exaggerated reactive oxygen species (ROS) production, reduced nitric oxide (NO) bioavailability, disturbances in the blood-brain barrier (BBB) and neural-parenchymal homeostasis, 10 men (24± 1years) were exposed to a 10min IH trial (100% O2 ) while receiving intravenous saline and ascorbic acid (AA, 3 g) infusion. Internal carotid artery blood flow (ICABF), vertebral artery blood flow (VABF) and total CBF (tCBF, Doppler ultrasound) were determined. Arterial and right internal jugular venous blood was sampled to quantify the cerebral metabolic rate of oxygen (CMR ), transcerebral exchanges (TCE) of NO end-products (plasma nitrite), antioxidants (AA and AA plus dehydroascorbic acid (AA+DA)) and oxidant biomarkers (thiobarbituric acid-reactive substances (TBARS) and 8-isoprostane), and an index of BBB disruption and neuronal-parenchymal damage (neuron-specific enolase; NSE). IH reduced ICABF, tCBF and , while VABF remained unchanged. Arterial 8-isoprostane and nitrite TCE increased, indicating that CBF decline was related to ROS production and reduced NO bioavailability. AA, AA+DA and NSE TCE did not change during IH. AA infusion did not change the resting haemodynamic and metabolic parameters but raised antioxidant defences, as indicated by increased AA/AA+DA concentrations. Negative AA+DA TCE, unchanged nitrite, reductions in arterial and venous 8-isoprostane, and TBARS TCE indicated that AA infusion effectively inhibited ROS production and preserved NO bioavailability. Similarly, AA infusion prevented IH-induced decline in regional and total CBF and re-established . These findings indicate that ROS play a role in CBF regulation and metabolism during IH without evidence of BBB disruption or neural-parenchymal damage.

Electroanalysis of neurotransmitters via 3D gold nanoparticles and a graphene composite coupled with a microdialysis device

We developed a novel biosensor, which used the uniform graphene oxide (GO) to afford gold nanoparticles (GNPs). The advantages of this biosensor are the better sensitivities not only of GO but also the GNPs fabricated on it for neurotransmitters, especially the lower cost in biosensor modification. The modified composite was characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), energy dispersive spectroscopy (EDS) and electrochemical methods. The determination conditions were optimized and the peak currents of DA and 5‑HT were linear, with the concentrations in the range of 9.0 × 10−7 to 7.0 × 10−5 M for DA, and 6.0 × 10−7 to 4.0 × 10−5 M for 5‑HT. The detection limits were 7.0 × 10−9 M for 5‑HT and 5.6 × 10−8 M for DA. A micro-capacity electrolytic cell was designed using the modified biosensor to connect to the microdialysis device and it was successfully applied to determine the concentrations of DA and 5‑HT in the samples, with a spiked recovery of 82.0–118%.

Relationship Between the Anxious Symptoms and the Neurotransmitter in Parkinson's Mice with Different Dosages of MPTP

ABSTRACT This study aims to explore the relationship between the anxious symptoms and the impairment of 5-hydroxytryptamine system in PD mice induced by different dosages of MPTP. The mice from the three model groups, the low-dose, dose and high-dose group, took longer time in the dark box than those in the control group (P<0.05). However, no statistically significant differences were found among the model groups. The number of open arm entry (OE) and the open arm time (OT) were significant lower in the model group than those in the control group in the elevated plus-maze test (P＜0.05). The percentage of OE in modle group was significantly lower compared with the control group (P＜0.05). The concentrations of striatum DA, HVA, 5-HT, and 5-HIAA were significantly reduced in the three model groups compared to the control group (P＜0.05). The 5-HT concentrations of high-dose group was significantly lower than those of the control group in the prefrontal cortex (P＜0.05). Anxiety symptoms were appeared in the three model groups of early PD mice, but no difference existed among these groups. The 5-hydroxytryptamine system was damaged after MPTP injection, which could lead to anxiety. However, the impairment of 5-hydroxytryptamine system induced by MPTP was dose-independent.

Dorsal hypothalamic dopaminergic neurons play an inhibitory role in the hypothalamic-pituitary-adrenal axis via activation of D2R in mice.

The present study investigated the effects of dorsal hypothalamic dopamine (dh-DA) neurons on activation of hypothalamic-pituitary-adrenal (HPA) axis in adult male mice. Tyrosine hydroxylase-labelled DA neurons, DA content, c-Fos immune-positive (c-Fos+) cells and CRH expression in paraventricular nuclei (PVN), serum CORT and ACTH were examined at 4-, 8-, and 12-hour after a signal injection of MPTP (20mgkg-1 ) respectively. The dh-DA neurons and DA content in PVN at 4-hour post-MPTP were reduced with recovery at 12-hour post-MPTP, while decline of nigrostriatal DA neurons and DA content in striatum started from 12-hour post-MPTP. Number of c-Fos+ cells, and CORT/ACTH levels increased at 4-hour post-MPTP, followed by recovery at 12-hour post-MPTP. The CRH mRNA was elevated at 4-hour post-MPTP, and sustained for over 12hours. At 2-hour post-MPTP, PVN-injection of D2R agonist quinpirole corrected the increases in c-Fos+ cells, CORT/ACTH and CRH mRNA, but D1R agonist SKF38393 did not. PVN-injection of D2R antagonist L-sulpiride alone caused increases in c-Fos+ cells, CORT/ACTH and CRH mRNA. Similarly, PVN-injection of CB1R agonist WIN552,12 prevented the increases in c-Fos+ cells and CORT/ACTH rather than CRH mRNA, which were blocked by CB1R antagonist AM251. Levels of PKA and CREB phosphorylation in PVN were increased at 4-hour post-MPTP, which were blocked by quinpirole, but not WIN552,12. PKA inhibitor H89 corrected the increase of CRH mRNA at 8-hour post-MPTP. The activation of dh-DA neurons regulates negatively HPA axis through targeting D2Rs of CRH neurons to enhance endocannabinoid release and inhibit PKA-CREB pathway.

Vitamin D protects dopaminergic neurons against neuroinflammation and oxidative stress in hemiparkinsonian rats

BackgroundThe deficiency in 1α, 25-dihydroxyvitamin D3 (VD3) seems to increase the risk for neurodegenerative pathologies, including Parkinson’s disease (PD). The majority of its actions are mediated by the transcription factor, VD3 receptor (VD3R).MethodsThe neuroprotective effects of VD3 were investigated on a PD model. Male Wistar rats were divided into the following groups: sham-operated (SO), 6-OHDA-lesioned (non-treated), and 6-OHDA-lesioned and treated with VD3 (7 days before the lesion, pre-treatment or for 14 days after the 6-OHDA striatal lesion, post-treatment). Afterwards, the animals were subjected to behavioral tests and euthanized for striatal neurochemical and immunohistochemical assays. The data were analyzed by ANOVA and the Tukey test and considered significant for p < 0.05.ResultsWe showed that pre- or post-treatments with VD3 reversed behavioral changes and improved the decreased DA contents of the 6-OHDA group. In addition, VD3 reduced the oxidative stress, increased (TH and DAT), and reduced (TNF-alpha) immunostainings in the lesioned striata. While significant decreases in VD3R immunoreactivity were observed after the 6-OHDA lesion, these changes were blocked after VD3 pre- or post-treatments. We showed that VD3 offers neuroprotection, decreasing behavioral changes, DA depletion, and oxidative stress. In addition, it reverses partially or completely TH, DAT, TNF-alpha, and VD3R decreases of immunoreactivities in the non-treated 6-OHDA group.ConclusionsTaken together, VD3 effects could result from its anti-inflammatory and antioxidant actions and from its actions on VD3R. These findings should stimulate translational research towards the VD3 potential for prevention or treatment of neurodegenerative diseases, as PD.

Application of flow cytometry with a fluorescent dye to measurement of intracellular nitric oxide in plant cells

Main conclusionA simple and rapid method involving flow cytometry and NO-specific probe (DAF-FM DA) proved useful for detection and determination of intracellular NO production in Medicago truncatula suspension cells and leaves as well as in cells of Avena fatua, Amaranthus retroflexus embryos and leaves.The measurement of nitric oxide (NO) in plant material is important for examining the regulatory roles of endogenous NO in various physiological processes. The possibility of detecting and determining intracellular NO production by flow cytometry (FCM) with 4-amino-5-methylamino-2′,7′-difluorofluorescein (DAF-FM DA), an NO-specific probe in Medicago truncatula cells in suspension and leaves as well as in cells of embryos and leaves of Avena fatua L. or Amaranthus retroflexus L. was explored. To detect and measure NO production by cell suspension or embryos and leaves, the recommended DAF-FM DA concentration is 5 or 10 µM, respectively, applied for 30 min. Exogenous NO increased the intensity of the fluorescent signal in embryos and leaves of both plants, while carboxy-PTIO (cPTIO), an NO scavenger, decreased it. Thus, these results demonstrate that NO can be detected and an increase and a decrease of its intracellular level can be estimated. Wounding was observed to increase the fluorescence signal, indicating an increase in the intracellular NO level. In addition, the levels of exogenous and endogenous ascorbic acid were demonstrated to have no effect on the NO-related fluorescence signal, indicating the signal’s specificity only in relation with NO. The applicability of the proposed method for detection and determination of NO was confirmed (1) by in situ NO imaging in cell suspensions and (2) by determining the NO concentration in embryos and leaves using the Griess reagent. In view of the data obtained, FCM is recommended as a rapid and simple method with which to detect and determine intracellular NO production in plant cells.

Preparation and properties of polylactide/hydroxyapatite/polydopamine composites

A series of poly(lactic acid)/hydroxyapatite/polydopamine (PLA/HA/PDA) composites were fabricated via soution blending and casting method using CH2Cl2 as solvents. The physicochemical properties of the resulting composites were characterized by Fourier transform infrared spectroscopy, X‐ray powder diffraction, scanning electron microscopy, thermogravimetric analysis, and Rheological analysis. Particularly, the in vitro degradation, hydrophilic of PLA/HA/PDA composites was systematically investigated. The influences of DA content on thermal stabilities, hydrophilic, and rheological behavior properties of composites were evaluated. The results showed that the addition of DA and HA not only improved the thermal stability of PLA, but also improved the hydrophilic of PLA‐based composites. The obtained PLA/HA/PDA composites may be a promising material for load‐bearing orthopedic implants. POLYM. ENG. SCI., 58:2256–2263, 2018. © 2018 Society of Plastics Engineers

INFLAMMATORY MARKERS AND NEUROPEPTIDES CHARACTERISTIC OF PARKINSON’S DISEASE AND THEIR RESPONSE TO VISUALIZATION AND SUGGESTION BASED MIND-BODY THERAPY

Progress in elucidating neuroimmune connections has created new opportunities for improving the treatment of Parkinson’s disease (PD). In recent years, mind-body therapies have been shown to have positive effects on the immune and nervous systems, but interactions at the molecular level have not been tested. Thus, the main aim of the present study was to investigate the effects of therapy based on visualization and suggestion on the concentrations of IL-6, CRP, DA, BDNF, CoQ10, and TAC in patients with advanced PD. Eight patients with PD and 8 elderly healthy men (control group) were enrolled in the study. The therapy lasted 19 days and consisted of three parts: individual sessions with the therapist, mixed (therapist and audio-file), and self-training (audio-file). Blood samples were taken before training and at the end of each part. The expected changes in the investigated markers was observed during therapy: the serum concentration of IL-6 and CRP decreased, whereas DA and BDNF increased, however, this change was observed only after the first part of intervention when the therapy was conducted by the therapist. In the subsequent stages, the levels returned to the baseline. Noteworthy, after the therapy, we observed a significant increase in the motor and intellectual skills of the PD patients. No such changes were observed in the control group. Mind-body therapy based on visualization and suggestions aimed at changing the concentrations of signaling molecules, which are crucial in the development or treatment of PD, may be an effective element in supporting pharmacological therapy.