Intracerebroventricular Research Articles

Abstract 112: Role Of Endogenous Brain Melanocortin-4 Receptor Activation In Regulating Blood Pressure And Metabolic Function In Offspring Of Parents With Obesity

We previously demonstrated that activation of the central nervous system (CNS) melanocortin system modulates sympathetic nerve activity (SNA) and blood pressure (BP) in obese Zucker rats and spontaneously hypertensive rats (SHRs). In the present study, we examined whether endogenous activation of the brain melanocortin-4 receptors (MC4R) contributes to the regulation of BP and metabolic function in adult male (24-26 weeks-old) obese and lean offspring from parents fed a normal (N) or high fat diet (H). The rats were implanted with telemetry probes to measure BP and heart rate (HR) 24-hrs/day, and an intracerebroventricular (ICV) cannula was placed into the lateral ventricle. After 1 week to recover from surgery and 2 days of control measurements, the MC4R antagonist (SHU-9119) was infused (1 nmol/h, ICV) for 7 days followed by a 7-day recovery period. MC4R antagonism markedly increased food intake in all groups; however, the increase was more pronounced in obese offspring from obese H-fed parents (HH), especially when analyzing the net cumulative increase in food intake during the 7 days of treatment (191±11 vs. 136±14, 65±18 and 72±12 g) compared with obese offspring from lean N-fed parents (NH), lean offspring from obese H-fed parents (HN) and lean offspring from lean parents (NN), respectively. This increased food intake was associated with more weight gain in HH compared with NH, HN and NN offspring (Δ: 92±12 vs. 81±17, 52±11 and 38±9 g). Plasma leptin and insulin levels were markedly increased in HH offspring compared to NH, HN and NN offspring. Compared to NH and NN offspring from lean parents, HH and HN offspring from obese parents exhibited higher baseline mean arterial pressure (125±2 and 122±3 vs. 118±1 and 113±3 mmHg) and greater reduction in BP during SHU-9119 infusion (average last 3 days of infusion: -14.3±0.1 and -5.6±0.5 vs. -9.8±0.2 and -3.4±0.2 mmHg, respectively). The reduction in HR during SHU-9119 infusion, however, was more pronounced in NH and NN groups compared with HH and HN offspring (average last 3 days of infusion: -55±2 and -43±1 vs. -34±2 and -34±1 bpm). These results suggest that endogenous activation of brain MC4R may contribute to the elevated BP in obese offspring but not lean offspring from obese parents.

Cannabidiol Modulating the Expression of Neurotrophin Signaling Pathways in Chronic Exposure to Methamphetamine in Rats During Abstinence Period.

Several neuropsychiatric disorders, such as addiction, have indicated variations in the levels of neurotrophic factors. As an extremely addictive stimulant, methamphetamine (METH) is associated with rising levels of abuse worldwide. We have recently demonstrated that repeated intracerebroventricular (ICV) of cannabidiol (CBD), the most important non-psychotomimetic compound, can lead to diminished impairing memory and hippocampal damage caused by chronic exposure to METH (CEM) in rats over the abstinence period. Furthermore, the results indicated a possible contribution of the neurotrophin signaling pathway (NSP) in regulating neurogenesis and survival. This study intends to evaluate whether these effects remained as measured in molecular pathways after the abstinence period. The animals were given 2mg/kg METH twice a day for 10 days. Then, we adopted real-time polymerase chain reaction (PCR) throughout the 10-day abstinence period to assess the CBD's effect (10 and 50μg/5μL) on the levels of the mRNA expression of the NSP. The findings suggested that CEM, when compared to the control group in the hippocampus, downregulated mRNA expression of NSP. Moreover, a dosage of 50 μg/5μL CBD may possibly enhance the mRNA expression level of BDNF/TrkB and NGF/TrkA in the hippocampus. Besides, the expression of RAF-1 mRNA level could be reversed significantly by both doses of CBD. According to our results, CBD may partly bring about neuroprotective effects by modulating the NSP. These findings set forth solid evidence demonstrating that CBD is a protective factor attributed to neuropsychiatric disorders, such as METH addiction.

Intracerebroventricular injection of ghrelin receptor antagonist alleviated NAFLD via improving hypothalamic insulin resistance.

Objective(s):Non-alcoholic fatty liver disease (NAFLD) is a hepatic manifestation of clinical metabolic syndrome. Insulin resistance is an important factor in the pathogenesis of NAFLD. Ghrelin, widely distributed in peripheral tissues and the central nervous system, plays a vital role in regulating food intake, energy balance, and substance metabolism. In this study, the effect of intracerebroventricular (ICV) injection of ghrelin receptor antagonist on NAFLD was explored.Materials and Methods:A rat model of NAFLD was established by feeding a high-fat diet, and a selective ghrelin receptor antagonist [D-Lys-3]-GHRP-6 was injected via ventricular intubation implantation. The serum total cholesterol (TC), triglycerides (TGs), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and hepatic TGs were measured using the colorimetric method. Fasting plasma glucose (FPG) and fasting plasma insulin (FPI) were determined to calculate homeostatic model assessment insulin resistance (HOMA-IR). Hematoxylin-eosin (HE) and Oil Red O staining were conducted to observe the pathological changes and lipid accumulation in the liver. Hosphatidylinositide3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway protein expressions were measured using western blot analysis.Results:ICV injection of [D-Lys-3]-GHRP-6 significantly reduced serum lipids, transaminase, and HOMA-IR, improved liver injury, and inhibited lipid accumulation in the liver of NAFLD rats. Moreover, ICV injection of [D-Lys-3]-GHRP-6 significantly up-regulated the phosphorylation levels of PI3K/Akt/mTOR signaling protein expressions in the hypothalamus, indicating a significant improvement in hypothalamic insulin resistance.Conclusion:Blockade of central ghrelin receptor can treat NAFLD possibly via the hypothalamic PI3K/Akt/mTOR signaling pathway to improve insulin resistance.

Abstract A2: Non-canonical AT 1 R/b-arrestin2 Activation In Brain As A Regulator Of Blood Pressure

The brain renin angiotensin system (RAS) is known for its role in cardiovascular and metabolic regulation. Angiotensin II (Ang II) is the major active product of the RAS, exerting most of its physiological effects through the angiotensin type-1 receptor (AT 1 R). Canonical or G protein-mediated signaling of the AT 1 R within the brain is known to induce dipsogenic and pressor responses to Ang II stimulation. Non-canonical or β-arrestin mediated signaling is thought to counterbalance the detrimental effects of canonical signaling. However, the role of the non-canonical AT 1 R/β-arrestin pathway within the brain is understudied. Therefore, we hypothesized that β-Arrestin activation within the brain contributes to blood pressure (BP) regulation. Global β-arrestin1 ( Arrb 1) and β-arrestin2 ( Arrb 2) knockout (KO) mice were employed to evaluate BP upon treatment with 1) deoxycorticosterone acetate (DOCA)-salt and 2) Ang II. Age- and sex-matched C57BL/6J mice served as controls. First, mice were instrumented with radiotelemetry implants and BP was continuously recorded. At baseline, Arrb2 -KO mice exhibited similar BP when compared to WT (WT=128±5.5 vs Arrb 2-KO=131±5.4 mmHg; n=8 and 9, respectively). However. Arrb2-KO mice exhibited exacerbated responses to DOCA-salt compared to WT (WT=152±12 vs Arrb 2-KO=163±10 mmHg; n=8 and 9, respectively; p=0.03). Second, BP was evaluated upon acute intracerebroventricular (ICV) injection of Ang II (1ug). Arrb -2KO mice showed a higher BP response to Ang II compared to WT (WT=143±12 vs Arrb 2-KO=168±10 mmHg; n=5 and 6, respectively). These findings suggest that activation of β-arrestin2 might counterbalance the effects of canonical activation of the AT 1 R through G proteins. Overall, β-arrestin2 in the brain appears to protect against cardiovascular diseases since the genetic ablation of β-Arrestin2 resulted in an exacerbated BP, particularly with brain-specific injection of Ang II.

Copper Modulates Adult Neurogenesis in Brain Subventricular Zone.

The subventricular zone (SVZ) in lateral ventricles is the largest neurogenic region in adult brain containing high amounts of copper (Cu). This study aims to define the role of Cu in adult neurogenesis by chelating labile Cu ions using a well-established Cu chelator D-Penicillamine (D-Pen). A neurosphere model derived from adult mouse SVZ tissues was established and characterized for its functionality with regards to neural stem/progenitor cells (NSPCs). Applying D-Pen in cultured neurospheres significantly reduced intracellular Cu levels and reversed the Cu-induced suppression of NSPC’s differentiation and migration. An in vivo intracerebroventricular (ICV) infusion model was subsequently established to infuse D-Pen directly into the lateral ventricle. Metal analyses revealed a selective reduction of Cu in SVZ by 13.1% (p = 0.19) and 21.4% (p < 0.05) following D-Pen infusions at low (0.075 μg/h) and high (0.75 μg/h) doses for 28 days, respectively, compared to saline-infused controls. Immunohistochemical studies revealed that the 7-day, low-dose D-Pen infusion significantly increased Ki67(+)/Nestin(+) cell counts in SVZ by 28% (p < 0.05). Quantification of BrdU(+)/doublecortin (DCX)(+) newborn neuroblasts in the rostral migration stream (RMS) and olfactory bulb (OB) further revealed that the short-term, low-dose D-Pen infusion, as compared with saline-infused controls, resulted in more newborn neuroblasts in OB, while the high-dose D-Pen infusion showed fewer newborn neuroblasts in OB but with more arrested in the RMS. Long-term (28-day) infusion revealed similar outcomes. The qPCR data from neurosphere experiments revealed altered expressions of mRNAs encoding key proteins known to regulate SVZ adult neurogenesis, including, but not limited to, Shh, Dlx2, and Slit1, in response to the changed Cu level in neurospheres. Further immunohistochemical data indicated that Cu chelation also altered the expression of high-affinity copper uptake protein 1 (CTR1) and metallothionein-3 (MT3) in the SVZ as well as CTR1 in the choroid plexus, a tissue regulating brain Cu homeostasis. Taken together, this study provides first-hand evidence that a high Cu level in SVZ appears likely to maintain the stability of adult neurogenesis in this neurogenic zone.

Investigating brain uptake of a non-targeting monoclonal antibody after intravenous and intracerebroventricular administration.

Monoclonal antibodies play an important role in the treatment of various diseases. However, the development of these drugs against neurological disorders where the drug target is located in the brain is challenging and requires a good understanding of the local drug concentration in the brain. In this original research, we investigated the systemic and local pharmacokinetics in the brain of healthy rats after either intravenous (IV) or intracerebroventricular (ICV) administration of EGFRvIII-T-Cell bispecific (TCB), a bispecific monoclonal antibody. We established an experimental protocol that allows serial sampling in serum, cerebrospinal fluid (CSF) and interstitial fluid (ISF) of the prefrontal cortex in freely moving rats. For detection of drug concentration in ISF, a push-pull microdialysis technique with large pore membranes was applied. Brain uptake into CSF and ISF was characterized and quantified with a reduced brain physiologically-based pharmacokinetic model. The model allowed us to interpret the pharmacokinetic processes of brain uptake after different routes of administration. The proposed model capturing the pharmacokinetics in serum, CSF and ISF of the prefrontal cortex suggests a barrier function between the CSF and ISF that impedes free antibody transfer. This finding suggests that ICV administration may not be better suited to reach higher local drug exposure as compared to IV administration. The model enabled us to quantify the relative contribution of the blood-brain barrier (BBB) and Blood-CSF-Barrier to the uptake into the interstitial fluid of the brain. In addition, we compared the brain uptake of three monoclonal antibodies after IV dosing. In summary, the presented approach can be applied to profile compounds based on their relative uptake in the brain and provides quantitative insights into which pathways are contributing to the net exposure in the brain.

Intranasal administration of neuropeptide Y significantly antagonized stress-induced colonic dysmotility via central GABAA receptors in male rats.

Stress plays a major role in the pathogenesis of many diseases. Central neuropeptide Y (NPY) counteracts the biological actions of corticotropin-releasing factor (CRF) and attenuates stress responses. Intracerebroventricular (ICV) administration of NPY significantly antagonized the inhibitory effects of chronic complicated stress (CCS) on gastrointestinal (GI) dysmotility in rats. However, ICV administration is an invasive technique. The effect of intranasal administration of NPY on the hypothalamus-pituitary-adrenal (HPA) axis and GI motility in CCS conditions have not been studied, and the inhibitory mechanism of NPY on CRF through the γ-aminobutyric acid (GABA)A receptor needs to be further investigated. A CCS rat model was set up, and NPY was intranasally administered every day before the stress loading. Furthermore, ICV administration of a GABAA receptor antagonist was performed daily. Hypothalamic CRF and NPY expressions were evaluated, serum corticosterone and NPY levels were analyzed, and colonic motor functions were assessed. CCS rats showed significantly increased CRF expression and corticosterone levels, which resulted in enhanced colonic motor functions. Intranasal NPY significantly increased hypothalamic NPY mRNA expression and reduced CRF mRNA expression and plasma corticosterone levels, helping to restore colonic motor functions. However, ICV administration of the GABAA receptor antagonist significantly abolished these effects induced by NPY. In conclusion, intranasal administration of NPY upregulates the hypothalamic NPY system. NPY may, through the GABAA receptor, significantly antagonize overexpressed central CRF and attenuate HPA axis activity in CCS conditions, influencing and helping to restore colonic motor function.

Inhibition of NLRP1-Dependent Pyroptosis Prevents Glycogen Synthase Kinase-3β Overactivation-Induced Hyperphosphorylated Tau in Rats.

Our previous study indicated that inhibition of NLRP1-dependent pyroptosis could decrease intracerebroventricular (ICV) injection of a protein kinase A (PKA) agonist- or streptozotocin (STZ)-induced hyperphosphorylated tau. In this study, we used a glycogen synthase kinase-3β (GSK-3β) overactivation rat model to reconfirm our previous results. ICV injection of wortmannin (WT, a PI3K inhibitor) and GF-109203X (GFX, a PKC inhibitor) was used to induce overactivation of GSK-3β in rats. We injected NLRP1 siRNA together with WT/GFX to evaluate the effect of the inhibition of NLRP1-dependent neuronal pyroptosis on hyperphosphorylated tau. Our results indicated that ICV injection of NLRP1 siRNA prevented ICV-WT/GFX-induced neuronal death, further improving the spatial memory of the rats in the Morris water maze test. ICV injection of NLRP1 siRNA downregulated the expression of ASC, caspase-1, and GSDMD and the contents of IL-1β and IL-18 in rat brains. ICV injection of NLRP1 siRNA also decreased hyperphosphorylated tau and the activity of GSK-3β. Thus, these results support our previous study that NLRP1-dependent pyroptosis could enhance hyperphosphorylation of tau protein.

Paclitaxel induces cognitive impairment via necroptosis, decreased synaptic plasticity and M1 polarisation of microglia

Context Paclitaxel (PTX) leads to chemotherapy brain (chemo-brain) which is characterised by cognitive impairment. It has been reported that necroptosis is associated with cognitive impairment in some neurodegenerative diseases, but it is not clear whether it is related to the development of chemo-brain. Objective To investigate the role of necroptosis and related changes in PTX-induced cognitive impairment. Materials and methods C57bl/6n mice were randomly divided into five groups: control, vehicle, and different concentrations of PTX (6, 8, 10 mg/kg). Two additional groups received pre-treatment with Gdcl3 or PBS through Intracerebroventricular (ICV) injection before PTX-treatment. Cognitive function, necroptosis, synaptic plasticity and microglia polarisation were analysed. Results PTX (10 mg/kg) induced significant cognitive impairment, accompanied by changes in synaptic plasticity, including decreased density of PSD95 (0.65-fold), BDNF (0.44-fold) and dendritic spines (0.57-fold). PTX induced necroptosis of 53.41% (RIP3) and 61.91% (MLKL) in hippocampal neurons, with high expression of RIP3 (1.58-fold) compared with the control group. MLKL (1.87-fold) exhibited the same trend, reaching a peak on the 14th day. The increased expression of iNOS (1.63-fold) and inflammatory factors such as TNF-α (1.85-fold) and IL-β (1.89-fold) compared to the control group suggests that M1 polarisation of microglia is involved in the process of cognitive impairment. Pre-treatment with Gdcl3 effectively reduced the number of microglia (0.50-fold), inhibited the release of TNF-α (0.73-fold) and IL-β (0.56-fold), and improved cognitive impairment. Conclusion We established a stable animal model of PTX-induced cognitive impairment and explored the underlying pathophysiological mechanism. These findings can guide the future treatment of chemo-brain.

The alpha-7 nicotinic acetylcholine receptor agonist GTS-21 does not affect food intake in rats

Obesity is a prevalent disease, but effective treatments remain limited. Agonists of the alpha-7 nicotinic acetylcholine receptor (α7nAChR) promote negative energy balance in mice, but these effects are not well-studied in rats. We tested the hypothesis that the α7nAChR agonist GTS-21 would decrease food intake and body weight in adult male Sprague Dawley rats. Contrary to our hypothesis, acute systemic administration of GTS-21 produced no significant effects on chow or high-fat diet (HFD) intake. Acute intracerebroventricular (ICV) GTS-21 also had no impact on chow intake, and actually increased body weight at the highest dose tested. Previous studies suggest that GTS-21 engages the food intake-suppressive glucagon-like peptide-1 (GLP-1) system in mice. As there are known species differences in GLP-1 physiology between mice and rats, we tested the ability of GTS-21 to elicit GLP-1 secretion in rats. Our results showed that plasma levels of total GLP-1 in rats were not significantly altered by peripheral GTS-21 injection. These results represent an advance in understanding how α7nAChR activation impacts energy balance control in rodents and suggest that there may be important differences between rats and mice in the ability of GTS-21/α7nAChR activation to increase secretion of GLP-1.

The effect of chronic stress and its preconditioning on spatial memory as well as hippocampal LRP1 and RAGE expression in a streptozotocin-induced rat model of Alzheimer’s disease

According to available evidence, prolonged or chronic exposure to stress is detrimental to various brain structures, including the hippocampus. The current study examined the expression of two critical blood-brain barrier receptors required for amyloid-beta clearance to understand better the mechanism by which chronic stress impairs learning and memory in patients with Alzheimer's disease (AD). Rats were randomly assigned to one of two groups in this study: experiment 1 and experiment 2. Each main group was then divided into four subgroups. Rats were bilaterally injected with streptozotocin (STZ, 3mg/kg, twice) using the intracerebroventricular (ICV) technique to induce the Alzheimer's model. Additionally, they were subjected to foot shock (1mA, 1Hz) for 10s every 60s (1h/day) for ten consecutive days prior to and following STZ injection. The Morris Water Maze (MWM) test was used to assess spatial learning and memory. Real-time PCR was used to determine Low-density lipoprotein receptor-related protein-1 (LRP1) and receptor for advanced glycation end-products (RAGE) mRNA levels in the hippocampus. Moreover, the animals' body weights were determined as physiological parameters in all groups. The results indicated that 10-day chronic electric foot shock stress reduced body weight, impaired spatial learning and memory, decreased hippocampal LRP1 mRNA expression, and increased hippocampal RAGE mRNA expression in a rat AD model. It can be concluded that chronic stress in conjunction with AD alters the expression of LRP1 and RAGE in the hippocampus. The findings pave the way for scientists to develop novel treatment strategies for AD.

Effect of ornithokinin on feeding behavior, cloacal temperature, voluntary activity and crop emptying rate in chicks

Bradykinin is a well-studied bioactive peptide associated with several physiological functions, including vasodilation and inflammation, in mammals. However, its avian homolog, ornithokinin, has received less research attention in birds. Therefore this study aimed to investigate the effect of intraperitoneal (IP) and intracerebroventricular (ICV) injections of ornithokinin on feeding behavior, cloacal temperature, voluntary activity, crop emptying rate, and blood constituents in chicks (Gallus gallus). We also investigated the effect of lipopolysaccharide (LPS), a cell wall component of gram-negative bacteria, on ornithokinin-associated gene expression was also investigated to determine whether activation of the ornithokinin system is induced by bacterial infection. Both IP and ICV injections of ornithokinin significantly decreased feed intake, cloacal temperature, voluntary activity, and crop emptying rate in chicks, but they did not affect the plasma concentration of corticosterone. Additionally, LPS significantly increased the expression of ornithokinin B2 receptor mRNA in several organs. Hence, ornithokinin is associated with a range of physiological responses in chicks and may be related to their response to bacterial infection.

Potential anti neuro‐inflammatory effect of BioCen‐128 in animal models of dementia

BackgroundBioCen‐128 is a new active pharmaceutical ingredient composed of a specific bovine thymic fraction of a polypeptide nature. Positive results of similar thymus extracts have been shown to be effective in delaying the processes associated with aging, immunosenescence and Alzheimer's disease (AD), where the inflammation plays an important role. Because of the anti‐inflammatory potential of BioCen‐128, the aim of this study was to evaluate the granuloma model induced by a cotton wool implantation and the model induced by intracerebroventricular (ICV) administration of streptozotocin (STZ).MethodThe experiment was carried out using male OF‐1cenp mice weighing 20 ± 2 g.ResultsMice administered BioCen‐128 in via the IP route at 5, 10 and 20 mg/kg of corporal weigh showed a decrease in the wet and dry weights of the granuloma, providing evidence of a systemic anti‐inflammatory effect. In the ICV model of STZ, the administration of BioCen‐128 improved cognitive function.ConclusionThese responses suggested an anti‐neuroinflammatory effect explainable by the action of thymosin β4 and thymosin alfa proteins. The results suggested that BioCen‐128 could be used in the prevention and treatment of some diseases, for example AD, where neuroinflammation is one of the biological events that take place.

Distribution of neuromedin U (NMU)-like immunoreactivity in the goldfish brain, and effect of intracerebroventricular administration of NMU on emotional behavior in goldfish

Neuromedin U (NMU) is a multifunctional neuropeptide implicated in regulation of smooth muscle contraction in the circulatory and digestive systems, energy homeostasis and the stress response, but especially food intake in vertebrates. Recent studies have indicated the possible involvement of NMU in the regulation of psychomotor activity in rodents. We have identified four cDNAs encoding three putative NMU variants (NMU-21, −25 and −38) from the goldfish brain and intestine. Recently, we have also purified these NMUs and the truncated C-terminal form NMU-9 from these tissues, and demonstrated their anorexigenic action in goldfish. However, there is no information on the brain localization of NMU-like immunoreactivity and the psychophysiological roles of NMU in fish. Here, we investigated the brain distribution of NMU-like immunoreactivity and found that it was localized throughout the fore- and mid-brains. We subsequently examined the effect of intracerebroventricular (ICV) administration of NMU-21, which is abundant only in the brain on psychomotor activity in goldfish. As goldfish prefer the lower to the upper area of a tank, we developed an upper/lower area preference test in a tank for evaluating the psychomotor activity of goldfish using a personal tablet device without an automatic behavior-tracking device. ICV administration of NMU-21 at 10 pmol g-1 body weight (BW) prolonged the time spent in the upper area of the tank, and this action mimicked that of ICV administration of the central-type benzodiazepine receptor (CBR) agonist tofisopam at 100 pmol g-1 BW. These results suggest that NMU-21 potently induces anxiolytic-like action in the goldfish brain.

Depressive-like behavior accompanies neuroinflammation in an animal model of bipolar disorder symptoms induced by ouabain

IntroductionA previous study from our Laboratory showed no alteration in inflammatory parameters seven days after ouabain (OUA) administration, a Na+K+ATPase inhibitor, which was previously considered only a mania model. However, the administration of OUA in rats was recently validated as a model of bipolar disorder (BD) symptoms, demonstrating that 14 days after single intracerebroventricular (ICV) administration, OUA also induces depressive-like behavior. Therefore, it is important to investigate the long-term effect of OUA on inflammatory parameters since this mechanism seems to play a key role in BD physiopathology. MethodsAdult male Wistar rats received a single ICV administration of OUA or artificial cerebrospinal fluid (aCSF). From the fourth day after the ICV infusion, the rats received saline or Lithium (Li) for 14 days. The open-field test was performed on the 7th day after OUA. On the 14th day, locomotion was re-evaluated, and the forced swimming test (FST) was used to evaluate depressive-like behavior. Inflammatory parameters were assessed in the frontal cortex and hippocampus. ResultsOUA increased the locomotion of rats after seven days, considered a mania-like behavior. In the FST, OUA increased the time of immobility on the 14th day, considered a depressive-like behavior. Li reversed the mania-like behavior and partially reversed the depressive-like behavior. Furthermore, OUA increased the levels of interleukin (IL)-1β, IL-6, IL-10, TNF-α, and CINC-1 in the frontal cortex and hippocampus. Li treatment reverses all these inflammatory alterations. ConclusionThis study suggests that the long-term Na+K+ATPase inhibition effects induce depressive-like behavior, which was accompanied by inflammation in the BD symptoms model.

Outcome and prognostic factors of very old patients with primary CNS lymphoma: a retrospective analysis of patients ≥80 years treated with high-dose methotrexate-based chemotherapy

Although >10% of primary CNS lymphoma (PCNSL) patients are ≥80 years, data on this population are limited. We analyzed 19 consecutive octogenarians with PCNSL treated with high-dose methotrexate (HD-MTX)-based chemotherapy at our institution concerning outcome, prognostic factors and living conditions at six-month follow-up for 11 patients alive and in remission. Seven patients received intracerebroventricular (ICV) treatment additional to systemic therapy. Median follow-up was 27.3 months. Median overall survival was 16.3 months. Positive prognosticators of survival were application of ICV treatment (p = 0.033) and female gender (p = 0.015). All 11 patients alive and in remission at 6-month follow-up were living at home with a median Karnofsky performance score of 60 (range 50–90) and a median instrumental activities of daily living score of 3 (range 1–8). HD-MTX-based polychemotherapy including ICV treatment was feasible in this population, patients in remission needed moderate support in everyday live.

Central Kisspeptin Does Not Affect ERK1/2 or p38 Phosphorylation in Oxytocin Neurons of Late-Pregnant Rats.

Oxytocin is secreted by hypothalamic supraoptic nucleus (SON) and paraventricular nucleus (PVN) oxytocin neurons to induce uterine contractions during parturition. Increased activation of oxytocin neurons at parturition involves a network of afferent inputs that increase oxytocin neuron excitability. Kisspeptin fibre density increases around oxytocin neurons during pregnancy, and central kisspeptin administration excites oxytocin neurons only in late pregnancy. Kisspeptin signals via extracellular regulated kinase 1/2 (ERK1/2) and p38. Therefore, to determine whether kisspeptin excites oxytocin neurons via ERK1/2-p38 signalling in late-pregnant rats, we performed immunohistochemistry for phosphorylated ERK1/2 (pERK1/2) and phosphorylated p38 (p-p38) in oxytocin neurons of non-pregnant and late-pregnant rats. Intracerebroventricular (ICV) kisspeptin administration (2 µg) did not affect pERK1/2 or p-p38 expression in SON and PVN oxytocin neurons of non-pregnant or late-pregnant rats. Furthermore, ICV kisspeptin did not affect pERK1/2 or p-p38 expression in brain areas with major projections to the SON and PVN: the nucleus tractus solitarius, rostral ventrolateral medulla, locus coeruleus, dorsal raphe nucleus, organum vasculosum of the lamina terminalis, median preoptic nucleus, subfornical organ, anteroventral periventricular nucleus, periventricular nucleus and arcuate nucleus. Hence, kisspeptin-induced excitation of oxytocin neurons in late pregnancy does not appear to involve ERK1/2 or p38 activation in oxytocin neurons or their afferent inputs.

Chronic intracerebroventricular infusion of angiotensin II causes dose- and sex-dependent effects on intake behaviors and energy homeostasis in C57BL/6J mice.

The renin-angiotensin system (RAS) within the brain is implicated in the control of fluid and electrolyte balance, autonomic functions, blood pressure, and energy expenditure. Mouse models are increasingly used to explore these mechanisms; however, sex and dose dependencies of effects elicited by chronic intracerebroventricular (ICV) angiotensin II (ANG II) infusion have not been carefully established in this species. To examine the interactions among sex, body mass, and ICV ANG II on ingestive behaviors and energy balance, young adult C57BL/6J mice of both sexes were studied in a multiplexed metabolic phenotyping system (Promethion) during chronic infusion of ANG II (0, 5, 20, or 50 ng/h). At these infusion rates, ANG II caused accelerating dose-dependent increases in drinking and total energy expenditure in male mice, but female mice exhibited a complex biphasic response with maximum responses at 5 ng/h. Body mass differences did not account for sex-dependent differences in drinking behavior or total energy expenditure. In contrast, resting metabolic rate was similarly increased by ICV ANG II in a dose-dependent manner in both sexes after correction for body mass. We conclude that chronic ICV ANG II stimulates water intake, resting, and total energy expenditure in male C57BL/6J mice following straightforward accelerating dose-dependent kinetics, but female C57BL/6J mice exhibit complex biphasic responses to ICV ANG II. Furthermore, control of resting metabolic rate by ANG II is dissociable from mechanisms controlling fluid intake and total energy expenditure. Future studies of the sex dependency of ANG II within the brain of mice must be designed to carefully consider the biphasic responses that occur in females.

Evidence for preserved insulin responsiveness in the aging rat brain

Insulin appears to exert salutary effects in the central nervous system (CNS). Thus, brain insulin resistance has been proposed to play a role in brain aging and dementia but is conceptually complex and unlikely to fit classic definitions established in peripheral tissues. Thus, we sought to characterize brain insulin responsiveness in young (4–5 months) and old (24 months) FBN male rats using a diverse set of assays to determine the extent to which insulin effects in the CNS are impaired with age. When performing hyperinsulinemic-euglycemic clamps in rats, intracerebroventricular (ICV) infusion of insulin in old animals improved peripheral insulin sensitivity by nearly two-fold over old controls and comparable to young rats, suggesting preservation of this insulin-triggered response in aging per se (p < 0.05). We next used an imaging-based approach by comparing ICV vehicle versus insulin and performed resting state functional magnetic resonance imaging (rs-fMRI) to evaluate age- and insulin-related changes in network connectivity within the default mode network. In aging, lower connectivity between the mesial temporal (MT) region and other areas, as well as reduced MT signal complexity, was observed in old rats, which correlated with greater cognitive deficits in old. Despite these stark differences, ICV insulin failed to elicit any significant alteration to the BOLD signal in young rats, while a significant deviation of the BOLD signal was observed in older animals, characterized by augmentation in regions of the septal nucleus and hypothalamus, and reduction in thalamus and nucleus accumbens. In contrast, ex vivo stimulation of hippocampus with 10 nM insulin revealed increased Akt activation in young (p < 0.05), but not old rats. Despite similar circulating levels of insulin and IGF-1, cerebrospinal fluid concentrations of these ligands were reduced with age. Thus, these data highlight the complexity of capturing brain insulin action and demonstrate preserved or heightened brain responses to insulin with age, despite dampened canonical signaling, thereby suggesting impaired CNS input of these ligands may be a feature of reduced brain insulin action, providing further rationale for CNS replacement strategies.

The Role of Orexin-A in Water Intake in Water-deprived Rats

Background: The lateral hypothalamus (LH), which produces orexin, is vital for body solution homeostasis. Lateral hypothalamus (LH) lesion causes adipsia and its stimulation increases water intake. Objective: This study aimed to investigate the effect of an intracerebroventricular (ICV) injection of orexin-A (OXA) on water-drinking behavior in water-deprived rats. Metods: A total of 32 male Wistar rats (220–250 g) were used and divided into 4 groups, control (no injection), vehicle (Normal saline, 5 µL), OXA (30 µg/rat), SB-334867 (OXA receptor selective antagonist, 30 µg/rat). After the microinjection of drugs or vehicles in the right lateral ventricle, each rat was placed individually into the metabolic cage and the amount of water intake, the delay time for the first water intake, and the referral number for water intake were recorded for 4 h. Findings: This study showed that ICV administration of OXA increased both water intake and the referral number for water intake in water-deprived animals (P&lt;0.05). On the other hand, ICV administration of SB-334867 decreased water intake compared to vehicle and control groups. Conclusion: It can be concluded that OXA has a regulatory role in water drinking behavior in water-depriving states.