Arm Entries Research Articles

The effect of 5-HT4 serotonin receptors in the CA3 hippocampal region on D-AP5-induced anxiolytic-like effects: Isobolographic analyses

Increasing evidence shows the close relationship between hippocampal glutamatergic and serotonergic systems through the modulation of behavioral responses. This study aimed to investigate the possible involvement of 5-HT4 receptors in the CA3 hippocampal region in anxiolytic-like effects induced by D-AP5 (a competitive antagonist of the glutamate NMDA [N-Methyl-D-aspartate] receptor). Male Wistar rats were placed in the elevated plus maze (EPM) apparatus that is used to assess anxiety-related behaviors, and the percentages of open arm time (%OAT) and open arm entries (%OAE) which are associated with anxiety-related behaviors were measured. The close arm entries (CAE) which is correlated with locomotor activity was also evaluated. The results showed that, intra-CA3 injection of D-AP5 (0.4 μg/rat), RS67333 (1.2 μg/rat; a 5-HT4 receptor agonist), and RS23597-190 (1.2 μg/rat; a 5-HT4 receptor antagonist) increased %OAT and %OAE, indicating the anxiolytic-like effect of these drugs. Also, only RS23597-190 (1.2 μg/rat) decreased CAE. Intra-CA3 injection of sub-threshold dose of RS67333 (0.012 μg/rat) or RS23597-190 (0.012 μg/rat), 5 min before the injection of D-AP5 (0.2 μg/rat) increased %OAT, indicating potentiating the anxiolytic-like effect of D-AP5. The isobolographic analyses also showed the additive or synergistic anxiolytic-like effect of intra-CA3 co-administration of D-AP5 with RS67333 or RS23597-190, respectively. In conclusion, CA3 5-HT4 receptors are involved in D-AP5-induced anxiolytic-like behaviors in rats.

Role of Neuropeptide S on Behavioural and Neurochemical Changes of an Animal Model of Attention-Deficit/Hyperactivity Disorder

Neuropeptide S (NPS) is a recently discovered peptide signalling through its receptor NPSR, which is expressed throughout the brain. Since NPSR activation increases dopaminergic transmission, we now tested if NPSR modulates behavioural and neurochemical alterations displayed by an animal model of attention-deficit/hyperactivity disorder (ADHD), Spontaneous Hypertensive Rats (SHR), compared to its control strain, Wistar Kyoto rats (WKY). NPS (0.1 and 1 nmol, intracerebroventricularly (icv)) did not modify the performance in the open field test in both strains; however, NPSR antagonism with [tBu-d-Gly5]NPS (3 nmol, icv) increased, per se, the total distance travelled by WKY. In the elevated plus-maze, NPS (1 nmol, icv) increased the percentage of entries in the open arms (%EO) only in WKY, an effect prevented by pretreatment with [tBu-d-Gly5]NPS (3 nmol, icv), which decreased per se the %EO in WKY and increased their number of entries in the closed arms. Immunoblotting of frontal cortical extracts showed no differences of NPSR density, although SHR had a lower NPS content than WKY. SHR showed higher activity of dopamine uptake than WKY, and NPS (1 nmol, icv) did not change this profile. Overall, the present work shows that the pattern of functioning of the NPS system is distinct in WKY and SHR, suggesting that this system may contribute to the pathophysiology of ADHD.

“We are antidepressant also”: aspirin and diclofenac sodium

Background: Many studies have indicated that inflammation and depression are associated with each other. Present study was taken up to prove antidepressant effect of aspirin and diclofenac sodium.Methods: The present study was divided into 6 phases with 5 groups of animals N=10. In study 1, C57Bl mice were used and in remaining 4 studies swiss albino mice. Amitriptyline was standard drug used. For each study first group of animals was treated with a saline solution 1ml P.O., and second group of animals injected with 0.1 ml of 2% formalin. In group 3, 4, 5 animals depression was produced by stressors and treated with aspirin 14mg/kg P.O., diclofenac sod. 10 mg/kg P.O. and amitriptyline 10 mg/kg P.O., respectively. Antidepressant activity of aspirin and diclofenac sodium was determined by using forced swim test, tail suspension test, elevated plus maze test and light dark box test. Inflammatory mediators (IL-6, TNF-α) and central neurotransmitters (5-HT, NE, Ach) were estimated.Results: In light dark box test, latency of first crossing, time spent in dark area were decreased and no. of crossing increased significantly in the aspirin, diclofenac sod. treated animals. In forced swim test, the immobility time was decreased. Swiss albino mice treated with aspirin, diclofenac sod. showed decreased concentration of IL-6 and TNF-α and increased concentration of serotonin, nor epinephrine and acetylcholine. In elevated plus maze test, no. of open arm, closed arm entries, time spent in open arm increased and time spent in closed arm decreased. In tail suspension test immobility time was decreased.Conclusions: Aspirin and diclofenac sodium has antidepressant activity.

Effects of adipokinetic hormone/red pigment-concentrating hormone family of peptides in olfactory bulbectomy model and posttraumatic stress disorder model of rats

One of the major neuropeptide groups in insects is adipokinetic hormone/red pigment-concentrating hormone (AKH/RPCH) family of peptides. AKH had improving effects on depression and anxiety in animal models and it may be a new treatment choice in these disorders. Aim of this study was to investigate effects of Anax imperator AKH (Ani-AKH), Libellula auripennis AKH (Lia-AKH) and Phormia-Terra hypertrehalosemic hormone (Pht-HrTH) on animal behavior in olfactory bulbectomy (OBX) model and in posttraumatic stress disorder (PTSD) model of Wistar-albino rats. Lia-AKH and Pht-HrTH significantly increased time spent in escape platform’s quadrant compared to sham control while Lia-AKH significantly increased time spent in escape platform’s quadrant compared to OBX controls in probe trial of Morris water maze (MWM). Ani-AKH, Lia-AKH and Pht-HrTH significantly decreased immobility time compared to OBX controls in forced swimming test (FST). Pht-HrTH significantly increased %open arm time compared to OBX controls in elevated plus maze (EPM) test. Ani-AKH significantly increased %open arm entry compared to sham control while Ani-AKH and Pht-HrTH significantly increased %open arm entry compared to OBX controls in EPM. In PTSD study Ani-AKH and Lia-AKH significantly decreased immobility time compared to traumatized controls in FST. In acoustic startle reflex test, Ani-AKH, Lia-AKH and Pht-HrTH significantly decreased average startle amplitude compared to non-traumatized controls in PTSD study. Metabolomic studies showed that AKH may affect glutamatergic and dopaminergic system and neurochemistry. In conclusion, AKH peptides had wide ranging effects on behavior and improved performance in OBX and PTSD models in rats.

Neuropharmacological Characterization of Dioclea altissima Seed Lectin (DAL) in Mice: Evidence of Anxiolytic-like Effect Mediated by Serotonergic, GABAergic Receptors and NO Pathway.

Plant lectins have shown promising biological activities in the central nervous system (CNS). This study evaluated the effect of DAL, a lectin isolated from the seeds of the Dioclea altissima species, having binding affinity to D-glucose or D-mannose residues, on mice behavior. Mice (n=6/group) were treated (i.p.) with DAL (0.25, 0.5 or 1 mg/kg) or vehicle and subjected to several tests (open field/OFT, marble-burying/MBT, hole-board/HBT, elevated plus maze/PMT, tail suspension/ TST, forced swimming/FST or rotarod/RRT). Pizotifen, cyproheptadine, flumazenil, L-NAME, 7-NI, Larginine or yohimbine were administered 15 min before DAL (0.5 mg/kg) and the animals were evaluated on PMT. It was also verified whether the DAL effect depended on its structural integrity and ability to interact with carbohydrates. The results showed there were no neurobehavioral changes in the mice at the RRT, FST and locomotion in the OFT. DAL (0.25, 0.5 or 1 mg/kg) increased the behavior of grooming and rearing in the OFT, head dips in the HBT, pedalling in the TST and decreased the number of marbles hidden in the MBT. In the PMT, DAL (0.25, 0.5 and 1 mg/kg) and Diazepam increased the frequency of entries in the open arms and the time of permanence in the open arms without affecting the locomotor activity. The effect of DAL was dependent on carbohydrate interaction and protein structure integrity and it prevented by pizotifen, cyproheptadine, flumazenil, L-NAME and 7-NI, but not by L-arginine or yohimbine. DAL was found to have an anxiolytic-like effect mediated by the 5-HT and GABAergic receptors and NO pathway.

Neurocognitive Outcomes in a Cisternal Blood Injection Murine Model of Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) results in neurocognitive dysfunction and anxiety in humans and in animal models. Neurobehavioral tests such as the Morris Water Maze (MWM) and Elevated Plus Maze (EPM) tests are validated in several models of SAH but have not been tested in the murine cisternal blood injection SAH model. Adult C57BL/6 mice (n=16) were randomized into two groups. Group 1 (n=8) received sham surgery. Group 2 (n=8) underwent SAH with 60 µL of autologous blood injected into the cisterna magna. Mice were then tested using the Modified Garcia Score on post-operative day 2 (POD2), EPM on POD5 & POD16, and MWM on POD6-16.Brain tissues harvested on POD16 were stained with Fluoro-Jade C to identify neurodegeneration in the hippocampus and cortex and Iba-1 immunofluorescence staining for microglial activation in the dentate gyrus and CA1 region of the hippocampus. SAH mice showed increased escape latency on POD10. Swim distance was significantly increased on POD9-10 and swim speed was significantly decreased on POD6&POD10 in SAH mice. SAH mice exhibited a trend for lowered proportion of covered arm entries in EPM on POD16. Modified Garcia Score was not significantly different between the groups on POD2. The area of microglial activation in the dentate gyrus and CA1 region of the hippocampus was mildly increased but not significantly different at day 16 after SAH. Similarly, no significant differences were noted in the number of Fluoro-Jade C (+) cells in cortex or hippocampus. Cisternal single blood injection in mice produces mild neurocognitive deficits most pronounced in spatial learning and most evident 10 days after SAH.

A pyrazole-containing selenium compound modulates neuroendocrine, oxidative stress, and behavioral responses to acute restraint stress in mice

The contribution of oxidative stress has been described in numerous studies as one of the main pathways involved in the pathophysiology of anxiety and its comorbidities, such as chronic pain. Therefore, in this study, we investigated the anxiolytic-like, antiallodynic, and anti-hyperalgesic effects of 3,5-dimethyl-1-phenyl-4-(phenylselanyl)-1H-pyrazole (SePy) in response to acute restraint stress (ARS) in mice through the modulation of oxidative stress and neuroendocrine responses. Mice were restrained for 2 h followed by SePy (1 or 10 mg/kg, intragastrically) treatment. Behavioral, and biochemical tests were performed after further 30 min. The treatment with SePy reversed (i) the decreased time spent and the number of entries in the open arms of the elevated plus-maze apparatus, (ii) the decreased time spent in the central zone of the open field test and the increased number of grooming, (iii) the increased number of marbles buried, (iv) the increased response frequency of Von Frey Hair stimulation, and (v) the decreased latency time to nociceptive response in the hot plate test stress induced by ARS. Biochemically, SePy reversed ARS-induced increased levels of plasma corticosterone, and reversed the ARS-induced alterations in the levels of reactive species, lipid peroxidation, and superoxide dismutase and catalase activities in the prefrontal cortices and hippocampi of mice. Moreover, a molecular docking approach suggested that SePy may interact with the active site of the glucocorticoid receptor. Altogether, these results indicate that SePy attenuated anxiolytic-like behavior, hyperalgesia, and mechanical allodynia while modulating oxidative stress and neuroendocrine responses in stressed mice.

Absence of effects of intermittent access to alcohol on negative affective and anxiety-like behaviors in male and female C57BL/6J mice.

Alcohol use disorder is highly comorbid with other neuropsychiatric disorders such as depression and anxiety. Importantly, women and men are affected differentially by heavy drinking, with women experiencing longer negative affective states after intoxication and increased likelihood to present with comorbid mood or anxiety disorders. In rodents, several studies using different alcohol administration models have shown the development of depressive-like or anxiety-like phenotypes that emerge during abstinence. In this study, we compared the emergence of negative affective behaviors during abstinence from 7 weeks of two-bottle choice intermittent access to 20% alcohol in male and female C57BL/6J mice, a drinking paradigm little studied in this context. Half of the mice were tested 24hours into abstinence on the elevated zero maze and 19-20 days into abstinence in a novel object in the home cage encounter test. The other half of the mice were tested 27-28 days into abstinence with the novelty-suppressed feeding test. As expected, females drank more than males across the 7 weeks of access to alcohol. Drinking history did not affect performance on these tasks, with the exception of increasing the number of open arm entries on the elevated zero maze. Interestingly, in alcohol-naïve mice, females showed fewer anxiety-like behaviors than males in the elevated zero maze and the novelty-suppressed feeding test. Our results suggest that the intermittent access model does not reliably induce negative affective behaviors on these tasks, and that behavior in female and male mice differs across these tests. Rather, intermittent alcohol drinking may induce a mild form of behavioral disinhibition. Thus, the model of alcohol access is a critical factor in determining the appearance of behavioral disturbances that emerge during abstinence.

Effects of chronic exposure to low doses of Δ9- tetrahydrocannabinol in adolescence and adulthood on serotonin/norepinephrine neurotransmission and emotional behaviors.

BackgroundChronic exposure to D9-tetrahydrocannabinol (THC), the main pharmacological component of cannabis, during adolescence has been shown to be associated with an increased risk of depression and suicidality in humans. Little is known about the impact of the long-term effects of chronic exposure to low doses of THC in adolescent compared with adult rodents.MethodsTHC (1 mg/kg i.p., once per day) or vehicle was administered for 20 days in both adolescent (post-natal day 30–50) and young adult rats (post-natal day 50–70). After a long washout period (20 days), behavioral tests and electrophysiological recordings of serotonin and norepinephrine neurons were carried out.ResultsAdolescent THC exposure resulted in depressive behaviors: decreased latency to first immobility in the forced swim test and increased anhedonia in the sucrose preference test. Decreased entries in the open arms were observed in the elevated plus maze after adolescent and adult exposure, indicating an anxious phenotype. A significant reduction in dorsal raphe serotonergic neural activity without a change in locus coeruleus noradrenergic neural activity was found after adolescent and adult exposure.ConclusionsAltogether, these findings suggest that chronic low-dose THC exposure during the critical developmental period of adolescence and during adulthood could result in increased vulnerability of the serotonin system accompanied by anxiety symptoms. However, depressive phenotypes occur only after adolescent exposure but not after adult exposure, underscoring the greater vulnerability of young ages to the mental effects of cannabis.

Long-term metformin therapy improves neurobehavioral functions and antioxidative activity after cerebral ischemia/reperfusion injury in rats

Metformin (MET),an antidiabetic drug, has shown antioxidative and neuroprotective effects. In the present investigation, we aimed to study the probable effects of MET on cerebral ischemia/reperfusion in rats. Rats underwent cerebral ischemia/reperfusion and MET was administered orally at doses of 100 and 200 mg/kg for 56 days. Anxiety- and depressive-like behaviors were evaluated by elevated plus-maze or forced swimming tests, respectively. was assessed by. Cognitive functions were assessed by Y-maze continuous alternation task and morris water maze. The activity of SOD and the level of BDNF were measured in brains samples. Our results showed that administration of 200 mg/kg MET reduced the percent of brain edema (84.00 ± 2.13) in comparison with the ischemic animals (91.25 ± 2.25) (p < 0.05). Administration of 200 mg/kg MET in ischemic animals improved anxiety-like behavior by increasing the percentage of the open arms entries (46.51 ± 3.13) and the percentage of the open arms time (32.70 ± 2.49) in comparison with the cerebral ischemia group (26.35 ± 7.02 and 15.32 ± 5.78, respectively) (all p < 0.001). MET treatment (200 mg/kg) increased the cognition index of correct alternations (90.20 ± 4.95) in comparison with the cerebral ischemia group (59.50 ± 8.01) (p < 0.05). MET at the both doses reduced escape latency compared to the cerebral ischemia animals (all p < 0.05). In addition, 200 mg/kg MET increased the time spent in the target quadrant (16.06 ± 0.58) in comparison with the ischemic animals (9.84 ± 0.92) (p < 0.001) and the both doses of the drug increased the number of crossing (5.42 ± 0.36 and 6.5 ± 0.42, respectively) compared to the cerebral ischemia group (3.75 ± 0.31) (p < 0.05 and p < 0.001, respectively). Moreover, 200 mg/kg MET reduced the immobility time (47.50 ± 9.00) in comparison with the cerebral ischemia group (93.43 ± 8.28) (p < 0.001). Furthermore, the both doses of MET increased the BDNF levels (4590 ± 197.6 and 4767 ± 44.10, respectively) in comparison with the ischemic animals (3807 ± 42.56) (p < 0.01 and p < 0.001, respectively). Also, the both doses of the drug increased the SOD activity of brain (52.67 ± 0.33 and 55.00 ± 0.57, respectively) compared to the ischemic animals (49.33 ± 0.33) (p < 0.01 and p < 0.001, respectively). Based on our data, long-term MET therapy may improve behavioral disorders following cerebral ischemia/reperfusion and can be considered as a novel therapeutic approach for the treatment of brain ischemic conditions.

Bacopa monnieri alleviates aluminium chloride-induced anxiety by regulating plasma corticosterone level in Wistar rats.

Objectives Aluminium is present in food preparations, antacids and many medications. It causes neurodegeneration thereby resulting in a spectrum of neurological disorders such as dementia, Alzheimer's disease and anxiety. Bacopa monnieri (BM) is widely used in ayurvedic medicine to improve memory functions. Its anxiolytic property was investigated in this study by using elevated plus maze (EPM) and plasma corticosterone level. Methods Thirty rats were assigned into five groups. Control group received distilled water, and 0.5% tween 80, AlCl3 group received Aluminium Chloride (AlCl3), Protective groups (BM100+AlCl3 group and BM200+AlCl3 group) received AlCl3 and BM at two different doses, and the BM200 group received BM. The EPM experiment was performed at the end of the 4th week of oral administration of BM and AlCl3 followed by the measurement of plasma corticosterone. Results Oral administration of AlCl3 to rats increases the levels of anxiety as seen in a decrease in the percentage of entries into the open arms of EPM, an increase in grooming frequency and defecation index. However, the rats in the protective groups shown an increase in the percentage of open arm entries and rearing frequency, and decreased grooming frequency and defecation index. AlCl3 alone treated group showed a significant increase in the plasma corticosterone levels compared to the control group. Whereas the protective groups have shown a significant decrease in the plasma corticosterone levels than the AlCl3 alone treated group. Conclusions Hence the BM has potential role in reverting the anxiogenic effect of AlCl3 in the amygdala as it is evident from the plasma corticosterone levels and the EPM parameters of different groups under study.

Lycopene ameliorates PTSD-like behaviors in mice and rebalances the neuroinflammatory response and oxidative stress in the brain

Posttraumatic stress disorder (PTSD) is a mental disorder that can translate into severe economic problems. Lycopene is an aliphatic hydrocarbon carotenoid extracted from plants, including papayas, tomatoes, and water melons. Previous studies have shown that lycopene can produce antidepressant-like effects in rodent models of depression. However, little is known about its anti-PTSD-like effect. This was addressed in the present study by using the single prolonged stress (SPS) protocol to induce PTSD-like behavioral deficits in mice. Our results showed that 12 days of lycopene treatment at the dose of 10 and 20 mg/kg, but not at 5 mg/kg, ameliorated the PTSD-like phenotype induced by SPS, including the increase in freezing time in contextual fear paradigm, the decrease in time and entries in open arms in elevated plus maze test, and the decrease in distance and time in the central area of the open field test, without affecting the mouse locomotor activity. Mechanistic studies revealed that lycopene treatment (20 mg/kg, 12 days) could suppress the SPS-induced increase in levels of interleukin-6 (IL-6), IL-1β, tumor necrosis factor-α (TNF-α), and nitrite in the hippocampus and prefrontal cortex in mice, as well as the increased markers that indicate high levels of oxido-nitrosative stress in the hippocampus and prefrontal cortex in SPS mice. Lycopene treatment (20 mg/kg, 12 days) also suppressed the SPS-induced decrease in brain derived neurotrophic factor (BDNF) levels in the hippocampus and prefrontal cortex in mice. Overall, the anti-PTSD-like effect of lycopene may be associated with its anti-neuroinflammation and anti-oxidative stress activities.

Investigation of dose related effects of propolis on anxiety and some biochemical parameters with sympathetic skin response and increased T-maze

Aim: Propolis has been shown to have anti-microbial, antioxidant, anti-tumor, anxiolytic and anti-inflammatory effects. However, to the best of our knowledge, there are no studies on its anxiogenic effects. In this study, we aimed to investigate the effects of different doses of propolis on anxiety in rats with cold stress via sympathetic skin response (electrodermal activity) and elevated T maze. Methods: Forty Wistar albino male rats were used in the study, divided into four groups: The control group, low dose (10 mg/kg PRO), medium dose (30 mg/kg PRO) and high dose propolis groups (50 mg/kg PRO). Propolis was administered via gavage to all rats except the control group. Twenty minutes after injection, the anxiety scores of the rats were evaluated with an elevated T-maze, and their electrodermal activities (EDA) were measured. At the end of the experiment, some enzymatic and lipid values were measured with malondialdehyde (MDA) in blood samples. Results: The percentage of time spent on open arms and the number of open arm entries were lower in the 10mg/kg PRO group, while an increase was observed in the 30 mg/kg PRO group. EDA values were lower in the 30 mg / kg PRO (P=0.012; P=0.02, respectively) and 50 mg / kg PRO (P=0.013, P=0.02, respectively) groups as compared to the control group. MDA was significantly lower in the 30 mg/kg PRO and 50 mg/kg PRO groups. While AST value increased in the 30 mg / kg PRO group, ALT value decreased. Total cholesterol and triglyceride values were significantly lower in the 50 mg / kg PRO group. HDL value increased significantly after administration of propolis and LDL value decreased significantly only in the 10 mg/kg PRO group. Conclusions: According to the results obtained by EDA and T labyrinth methods, while low and high dose propolis, which was administered to rats after cold stress, showed an anxiogenic effect, medium dose propolis exerted an anxiolytic effect. It also decreased MDA values in the medium and high dose groups and influenced enzymatic and lipid values in favor of the rat. It was concluded that the anxiety-related effects of propolis were dose-dependent.

Anxiolytic and antidepressant effects of Ziziphus mucronata hydromethanolic extract in male rats exposed to unpredictable chronic mild stress: Possible mechanisms of actions

Ethnopharmacological relevanceZiziphus mucronata (ZM) is used traditionally in the treatment of mood and depression. However, no existing scientific data is confirming this traditional claim. Aim of the studyThe present study was planned to investigate the anxiolytic and antidepressant-like effects of this plant in a stressed-induced depression model in rats. Materials and methodsDepressive-like behaviors were induced by exposing rats to different stress paradigms daily for 30 days. A sucrose preference test was performed to assess anhedonia in rats. Anxiety and depression-related behavior were assessed. The oxidative parameters (lipid peroxidation, SOD and catalase activities) were evaluated. Pindolol and Flumazenil were also used to assess the mechanism of action of ZM extract. ResultsThe results showed that chronic administration of ZM (150, 300, and 600 mg/kg, p.o., 30 days) and imipramine treatment (20 mg/kg, p.o, 30 days) remarkably (P < 0.05) reversed the UCMS-induced behavioral changes observed in stress vehicle treated rats by reducing sucrose preference, decreased the immobility period in the FST and latency in NSF. Besides, ZM (300 and 600 mg/kg, p.o., 30 days) raised the percentages of time spent and number of open arms entries as well as the number of transitions. Also, ZM (300 mg/kg, (P < 0.05) decreased lipid peroxidation and increased both SOD and catalase activities (300 and 600 mg/kg, (P < 0.05)). These aforementioned behavioral indices were also completely nullified by pindolol a β-adrenoceptors blocker and 5-HT 1A/1B receptor antagonist but not by flumazenil, a benzodiazepine receptors antagonist. ConclusionZM improved symptoms of anxiety and depression in behavioral despair paradigm in chronically stressed rats. The observed effects could be due to its capacities to restore the antioxidant status, and probably the modulation of monoamines transmissions.

Ovariectomy Induces Microglial Cell Activation and Inflammatory Response in Rat Prefrontal Cortices to Accelerate the Chronic Unpredictable Stress-Mediated Anxiety and Depression

Perimenopausal women are associated with increased risks of depression and anxiety, which may be potentially related to the lack of ovarian hormone with antidepression activity in the body. However, the precise mechanism remains unclear so far. This study first adopted the Sprague-Dawley (SD) female rats to construct the ovariectomy (OVX) combined with a chronic unpredictable stress (CUS) model. Then, a series of behavioral experimental results revealed that the ovariectomized rats receiving CUS had remarkably elevated anxiety and depression behaviors relative to those in sham group rats, and the sucrose preference rate in the sucrose preference test (SPT) was evidently reduced. In elevated plus maze test (EPM) experiment, the open arm entry time and open arm duration were decreased. In the open field test (OFT), the number of line crossings, rearing number, center square entries, and center square duration were reduced; the grooming time was extended; and the number of fecal particles in rats was increased. In the forced swimming test (FST), the rat immobility rate was increased, while the numbers of swimming and crawling were decreased. Afterwards, we discovered that OVX downregulated the serum levels of estradiol and corticosterone in rats. Thereafter, IF results suggested that OVX dramatically induced the increasing of the number of activated microglial cells in prefrontal cortices and the level of M1-type marker iNOS. Finally, PCR results demonstrated that, compared with the sham group, the proinflammatory and prooxidative genes, such as IL-1β, IL-6, TNF-α, iNOS, and CX3CR1, were upregulated in the prefrontal cortices of OVX rats after CUS stimulation, whereas the anti-inflammatory factor Arg1 and microglial cell negative regulatory factor CD200 were downregulated. To sum up, OVX enhances the CUS-mediated anxiety and depression phenomena in rats, and its mechanism may be related to inducing the activation and polarization of microglial cells in the prefrontal cortex of animal and to accelerating the inflammatory response.

Phytochemical analyses, anxiolytic and anti-amnesic effect of methanol stem bark extract of &lt;i&gt;Vitex doniana&lt;/i&gt; (sweet) in mice

This study investigated the oral acute toxicity (LD50), anxiolytic and anti-amnesic effects of the methanol stem bark extract of Vitex doniana (MSVD) in mice. The anxiolytic and anti-amnesic effects were assessed using standard protocols. The phytoconstituents in MSVD was quantified. The MSVD was further analysed using Ultraviolet-visible (UV-VIS) and Fourier Transform Infra red (FTIR) fingerprints. The LD50 was &gt; 5000 mg/kg suggesting its safety. The MSVD (125, 250 and 500 mg/kg, p.o.) showed significant (p&lt;0.05) increase in the percentage open arm entry and duration on elevated plus maze as well as reduced the anxiety index as indexed from the open arm avoidance index indicating an anti-anxiety effect. Subsequently, MSVD significantly (p&lt;0.05) increased the percentage alternation reduced by scopolamine consistent with anti-amnesic effect. The phytoconstituents estimation of MSVD showed abundance of flavonoids. The UV-VIS spectra corresponded to the presence of flavonoid, phenolic acid derivatives and terpenoids while the FTIR revealed the presence of amine, hydroxyl, alkane, carboxylic, amide, ether, aromatic and carbonyl functional groups among others in MSVD. This study therefore, concluded that flavonoids, either in synergy or additive with other phytocompounds in MSVB may be responsible for the observed anxiolytic and anti-amnesic effects elicited by MSVD in this study.

SAT-293 Osteocalcin and Exercise Improve Mood and Cognition in Female Mice with High-Fat Diet Induced Type 2 Diabetes

The skeleton has been characterized as an endocrine organ, demonstrating a capacity to modulate cognition, mood and energy homeostasis (1,2). These endocrine actions of the skeleton have been attributed to the osteoblast-derived peptide osteocalcin. In mice, uncarboxylated osteocalcin (ucOCN) decreased the acquisition of type 2 diabetes mellitus (T2DM) and ameliorated depressive- and anxiety-like behaviours (1,2). Clinically, T2DM patients present with reduced serum osteocalcin levels and approximately 1 in 4 also suffer from co-morbid depression (3,4). The cognitive and metabolic benefits of ucOCN are similar to the beneficial effects of exercise that is recommended in treatment of both depression and T2DM. Here we compared the effects of ucOCN or exercise in female C57-BL/6J mice under two different metabolic conditions. Mice were fed either a high-fat diet (60% calories from fat) to induce T2DM or a control diet (10% calories from fat). Groups of mice were either sedentary or exercised daily by 30 min treadmill running for two months, with or without daily administration of ucOCN (30 ng/g/day). Mice with T2DM displayed depressive behaviours marked by a higher immobile time in tail suspension tests compared to control mice (97±25 n=11 vs 207±9.0 s n=12; t21=4.21, P=0.0004). Exercise and osteocalcin both improved depressive behaviour (137±8 n=12; t22=5.85, P<0.0001 & 127±15 s n=12; t22=4.46, P=0.0002). Anxiety, measured by the elevated-plus maze revealed the mice with T2DM displayed increased anxiety spending less time in the open arms and had a lower ratio of open to closed arm entries than the control group (0.37±0.03 n=10 vs 0.21±0.032 n=11; t19=3.56, P=0.0021). Neither exercise nor osteocalcin improved anxiety in the T2DM mice. The puzzle box test revealed the negative effects of the high-fat diet in problem solving and memory, where the sedentary mice displayed greater latencies to solve each task compared to control mice. Exercised and mice receiving osteocalcin displayed performances comparable to that of the control group. Under normal metabolic conditions (low fat diet), neither osteocalcin nor exercise altered responses in any of the behavioural tests. Together, these results: 1. The effects of osteocalcin on behaviour and cognition are comparable to that of the effects of exercise in female mice with T2DM; 2. Behaviour and cognition did not improve from exercise or osteocalcin in female mice on a low-fat diet.

Ferulic acid through mitigation of NMDA receptor pathway exerts anxiolytic-like effect in mouse model of maternal separation stress.

Background Experiencing early-life stress plays an important role in the pathophysiology of anxiety disorders. Ferulic acid is a phenolic compound found in some plants which has several pharmacological properties. N-methyl-D-aspartate (NMDA) receptors are involved in the pathophysiology of mood disorders. In this study we aimed to assess the anxiolytic-like effect of ferulic acid in a mouse model of maternal separation (MS) stress by focusing on the possible involvement of NMDA receptors. Methods Mice were treated with ferulic acid (5 and 40 mg/kg) alone and in combination with NMDA receptor agonist/antagonist. Valid behavioral tests were performed, including open field test (OFT) and elevated plus maze test (EPM), while quantitative real time polymerase chain reaction (qRT-PCR) was used to evaluate gene expression of NMDA subunits (GluN2A and GluN2B) in the hippocampus. Results Findings showed that treatment of MS mice with ferulic acid increased the time spent in the central zone of the OFT and increased both open arm time and the percent of open arm entries in the EPM. Ferulic acid reduced the expression of NMDA receptor subunit genes. We showed that administration of NMDA receptor agonist (NMDA) and antagonist (ketamine) exerted anxiogenic and anxiolytic-like effects, correspondingly. Results showed that co-administration of a sub-effective dose of ferulic acid plus ketamine potentiated the anxiolytic-like effect of ferulic acid. Furthermore, co-administration of an effective dose of ferulic acid plus NMDA receptor agonist (NMDA) attenuated the anxiolytic-like effect of ferulic acid. Conclusions In deduction, our findings showed that NMDA, partially at least, is involved in the anxiolytic-like effect of ferulic acid in the OFT and EPM tests.

English

The objectives of the study were to evaluate the analgesic, anxiolytic and sedative-like activities of methanol extract of leaves of Alpinia calcarata Roscoe in mice model. Analgesic activity was investigated using the acetic acid-induced writhing test and formalin-induced paw licking test. In vivo neuropharmacological effects, including anxiolytic and sedative effects were examined by open field, light-dark, elevated plus maze, thiopental sodium-induced sleeping time and hole cross tests behaviors in mice. The extract produced significant (p&lt;0.001) reduction in writhing and licking response in acetic acid-induced writhing and formalin-induced paw licking tests, respectively. Administration at a dose of 400 mg/kg.bw of leaves extract significantly (p&lt;0.001) attenuated anxiety-like behavior in mice by decreasing movement in open field, increasing the time spent and number of entries in the open arms of elevated plus maze, and a significant increase in the time spent in the illuminated compartment in the light box in the light-dark test. The extract significantly (p&lt;0.01) potentiated thiopental sodium-induced sleep and reduced the number of sectional crossings relative to the control group, indicating sedative effects. Based on the results obtained from in vivo activities, the leaves of A. calcarata was found to be a potential source of new analgesic, anxiolytic and sedative compounds. Key words: Alpinia calcarata, Swiss albino mice, analgesic, anxiolytic, sedative &nbsp

Therapeutic Effects of Human Amniotic Epithelial Stem Cells in a Transgenic Mouse Model of Alzheimer's Disease.

Alzheimer’s disease (AD), a progressive neurodegenerative disorder, is characterized clinically by cognitive decline and pathologically by the development of amyloid plaques. AD is the most common cause of dementia among older people. However, there is currently no cure for AD. In this study, we aimed to elucidate the therapeutic effects of human amniotic epithelial stem cells (hAESCs) in a transgenic mouse model of AD. Tg2576 transgenic (Tg) mice underwent behavioral tests, namely the Morris water maze and Y-maze tests, to assess their cognitive function. In the Morris water maze test, hAESC-treated Tg mice exhibited significantly shorter escape latencies than vehicle-treated Tg mice. In the Y-maze test, hAESC-treated Tg mice exhibited significantly higher rate of spontaneous alteration than vehicle-treated Tg mice, while the total number of arm entries did not differ between the groups. Furthermore, Congo red staining revealed that hAESCs injection reduced the number of amyloid plaques present in the brains of Tg mice. Finally, beta-secretase (BACE) activity was significantly decreased in Tg mice at 60 min after hAESCs injection. In this study, we found that intracerebral injection of hAESCs alleviated cognitive impairment in a Tg2576 mouse model of AD. Our results indicate that hAESCs injection reduced amyloid plaques caused by reduced BACE activity. These results indicate that hAESCs may be a useful therapeutic agent for the treatment of AD-related memory impairment.