Frequency Of Grooming Research Articles

Interaction specificity between leaf-cutting ants and vertically transmitted Pseudonocardia bacteria.

BackgroundThe obligate mutualism between fungus-growing ants and microbial symbionts offers excellent opportunities to study the specificity and stability of multi-species interactions. In addition to cultivating fungus gardens, these ants have domesticated actinomycete bacteria to defend gardens against the fungal parasite Escovopsis and possibly other pathogens. Panamanian Acromyrmex echinatior leaf-cutting ants primarily associate with actinomycetes of the genus Pseudonocardia. Colonies are inoculated with one of two vertically transmitted phylotypes (Ps1 or Ps2), and maintain the same phylotype over their lifetime. We performed a cross-fostering experiment to test whether co-adaptations between ants and bacterial phylotypes have evolved, and how this affects bacterial growth and ant prophylactic behavior after infection with Escovopsis.ResultsWe show that Pseudonocardia readily colonized ants irrespective of their colony of origin, but that the Ps2 phylotype, which was previously shown to be better able to maintain its monocultural integrity after workers became foragers than Ps1, reached a higher final cover when grown on its native host than on alternative hosts. The frequencies of major grooming and weeding behaviors co-varied with symbiont/host combinations, showing that ant behavior also was affected when cuticular actinomycete phylotypes were swapped.ConclusionThese results show that the interactions between leaf-cutting ants and Pseudonocardia bear signatures of mutual co-adaptation within a single ant population.Electronic supplementary materialThe online version of this article (doi:10.1186/s12862-015-0308-2) contains supplementary material, which is available to authorized users.

Central amygdalar nucleus treated with orexin neuropeptides evoke differing feeding and grooming responses in the hamster

Interaction of the orexinergic (ORXergic) neuronal system with the excitatory (glutamate, l-Glu) or the inhibitory (GABA) neurosignaling complexes evokes major homeostatic physiological events. In this study, effects of the two ORXergic neuropeptides (ORX-A/B) on their receptor (ORX-2R) expression changes were correlated to feeding and grooming actions of the hibernating hamster (Mesocricetus auratus). Infusion of the central amygdala nucleus (CeA) with ORX-A caused hamsters to consume notable quantities of food, while ORX-B accounted for a moderate increase. Interestingly the latter neuropeptide was responsible for greater frequencies of grooming with respect to both controls and the hamsters treated with ORX-A. These distinct behavioral changes turned out to be even greater in the presence of l-Glu agonist (NMDA) while the α1 GABAA receptor agonist (zolpidem, Zol) greatly reduced ORX-A-dependent feeding bouts. Moreover, ORX-A+NMDA mainly promoted greater ORX-2R expression levels with respect to ORX-A-treated hamsters while ORX-B+Zol was instead largely responsible for a down-regulatory trend. Overall, these features point to CeA ORX-2R sites as key sensory limbic elements capable of regulating eating and grooming responses, which may provide useful insights regarding the type of molecular mechanism(s) operating during feeding bouts.

Preliminary Study: Neurobehavioural Effects of Nauclea latifolia and Emilia sonchifolia in Mice Infected with Plasmodium berghei berghei

This study was designed to examine the effects of ethanolic leaf extracts of Nauclea latifolia and Emilia sonchifolia on anxiety, fear and locomotion in mice infected with plasmodium berghei berghei . Thirty male Swiss albino mice weighing between 26-30g divided into five groups with six mice in each group. Group 1 served as the Control group and was treated with 0.2ml of normal saline, Group 2 served as the parasitized non-treated, Group 3, was parasitized and treated with Coartem ® , Group 4 was parasitized then treated with Emilia sonchifolia , Group 5 was parasitized and treated with Nauclea latifolia and Group 6 was parasitized and treated with a combination of Nauclea latifolia and Emilia sonchifolia respectively. The mice were passaged with the parasite intraperitoneally and then administered extract orally using an orogavage cannula for a duration of 5 days. Behavioural tests were performed pretreatment (day 6 after parasite passage) and posttreatment (day 11). The results obtained showed that grooming frequency and stretch attend

The impact of atypical early histories on pet or performer chimpanzees.

It is widely accepted that an animal’s early history, including but not limited to its rearing history, can have a profound impact on later behavior. In the case of captive animals, many studies have used categorical measures such as mother reared or human reared that do not account for both the influence of human and conspecific interaction. In order to account for the influence of both human and conspecific early exposure to later behavior, we collected 1385 h of data on 60 chimpanzees, of which 36 were former pets or performers, currently housed at accredited zoos or sanctuaries. We developed a unique metric, the Chimpanzee-Human Interaction (CHI) Index that represented a continuous measure of the proportion of human and chimpanzee exposure subjects experienced and here focused on their exposure during the first four years of life. We found that chimpanzees who experienced less exposure to other chimpanzees as infants showed a lower frequency of grooming and sexual behaviors later in life which can influence social dynamics within groups. We also found chimpanzees who experienced more exposure to other chimpanzees as infants showed a higher frequency of coprophagy, suggesting coprophagy could be a socially-learned behavior. These results help characterize some of the long-term effects borne by chimpanzees maintained as pets and performers and may help inform managers seeking to integrate these types of chimpanzees into larger social groups, as in zoos and sanctuaries. In addition, these results highlight the necessity of taking into account the time-weighted influence of human and conspecific interactions when assessing the impact that humans can have on animals living in captivity.

Sub‐lethal effects of capture and collaring on wildlife: Experimental and field evidence

ABSTRACTWe used both experimental and observational approaches to investigate sub‐lethal effects of capture and radiocollaring on pygmy rabbits (Brachylagus idahoensis) in Idaho and Washington during 2004–2008. We expected that attachment of collars would increase rates of grooming behaviors and alter patterns of space use. Frequency of grooming was >3 times higher following attachment of radiocollars on captive rabbits; however, the grooming rate declined rapidly and returned to within 5% of pre‐collaring levels after 7 days. Free‐ranging rabbits exhibited relatively longer distance movements immediately following and during the 2 weeks after capture and attachment of radiocollars, but those movements decreased during weeks 3–4 post‐collaring. Rabbits also shifted use areas away from capture locations. Our results suggest that: 1) rabbits became habituated to the presence of collars with respect to grooming; and 2) although, magnitude of movements following capture and collaring in the field attenuated with time, some animals continued to avoid capture areas up to 4 weeks after collaring. A better understanding of potential effects of telemetry on wildlife can help to improve the quality of data collected, design ways to mitigate the impacts on animals, and enhance the ethical conduct of wildlife research. © 2014 The Wildlife Society.

The Effects of Permanent Injury on the Behavior and Diet of Commensal Chacma Baboons (Papio ursinus) in the Cape Peninsula, South Africa

Primates may suffer injury from both natural (fights with conspecifics, predators) and human-induced (snares, power-lines and guns) causes. Though behavioral flexibility may allow primates to compensate for injuries, permanent disabilities, such as the loss of a limb, may adversely affect both foraging and locomotory efficiency and ultimately the survival and fitness of individuals. In the Cape Peninsula, South Africa, members of the chacma baboon population (Papio ursinus) experience chronic levels of conflict with humans that manifests in high levels (15%) of disabled baboons in groups that overlap with residential areas. In this study we investigate the potential impact of such disabilities by comparing the behavior and diet of disabled baboons with uninjured baboons matched closely for age, sex, and social status from groups of a similar size and composition for 8 mo, from May to December 2005. Disabled baboons spent more time resting and traveling and less time feeding than uninjured baboons. Disabled and uninjured baboons had similar diets but the former consumed fewer food items with high handling costs and fed more on high return foods than the latter. There was no difference in the frequency of grooming or social vigilance behaviors, as might be expected if disability had compromised either competitive ability or predation risk. Further, there was no difference in the survival of disabled or uninjured individuals in each group. Together these results suggest that while permanent injury may affect the behavior and diet of Peninsula baboons, that these constraints may be offset by access to anthropogenic food sources and the lack of natural predators. Disability in baboons may lead to obligate raiding of high-return anthropogenic foods, which is an important challenge for the ongoing management of this population.

Enriched environment prevents cognitive and motor deficits associated with postnatal MK-801 treatment.

Previous studies have shown the beneficial effects of enriched environment (EE) in rescuing behavioral deficits such as pre-pulse inhibition and locomotor hyperactivity associated with N-methyl-D-aspartate (NMDA) receptor blockade; however, cognitive deficits remain unresponsive. We designed experiments to determine the consequences of raising rat pups in an EE on several behavioral aberrations, mainly cognitive deficits, observed in rats postnatally exposed to MK-801 (NMDA receptor antagonist). Male Wistar rats were injected with MK-801 (1mg/kg) from postnatal day (P) 6-10. Rat pups were housed in an EE from birth up to the time of behavioral experiments at P28-34. The effects of EE in correcting MK-801-associated behaviors were assessed by rotarod, wire grip, open filed, and Morris water maze tests. We found that EE not only has beneficial effects on cognitive performance of normal rats but also prevents spatial learning and memory deficits in Morris water maze induced by MK-801. Postnatal MK-801 treatment also led to motor deficits both in wire grip and accelerating rotarod tests. These deficits were not observed in MK-801-treated rats raised in EE. In the open field test, EE prevented increase in "frequency of grooming" and decrease in "time spent in the center" associated with MK-801. Our results suggest that exposure to an EE would be strongly beneficial in correcting deficits, notably cognitive, associated with MK-801. Given that the postnatal MK-801 treatment represents an animal model of schizophrenia, we propose timely environmental interventions might be an effective strategy in the protection against schizophrenia.

Rapid behavioural gregarization in the desert locust, Schistocerca gregaria entails synchronous changes in both activity and attraction to conspecifics

Desert Locusts can change reversibly between solitarious and gregarious phases, which differ considerably in behaviour, morphology and physiology. The two phases show many behavioural differences including both overall levels of activity and the degree to which they are attracted or repulsed by conspecifics. Solitarious locusts perform infrequent bouts of locomotion characterised by a slow walking pace, groom infrequently and actively avoid other locusts. Gregarious locusts are highly active with a rapid walking pace, groom frequently and are attracted to conspecifics forming cohesive migratory bands as nymphs and/or flying swarms as adults. The sole factor driving the onset of gregarization is the presence of conspecifics. In several previous studies concerned with the mechanism underlying this transformation we have used an aggregate measure of behavioural phase state, Pgreg, derived from logistic regression analysis, which combines and weights several behavioural variables to characterise solitarious and gregarious behaviour. Using this approach we have analysed the time course of behavioural change, the stimuli that induce gregarization and the key role of serotonin in mediating the transformation. Following a recent critique that suggested that using Pgreg may confound changes in general activity with genuine gregarization we have performed a meta-analysis examining the time course of change in the individual behaviours that we use to generate Pgreg. We show that the forced crowding of solitarious locusts, tactile stimulation of the hind femora, and the short-term application of serotonin each induce concerted changes in not only locomotion-related variables but also grooming frequency and attraction to other locusts towards those characteristic of long-term gregarious locusts. This extensive meta-analysis supports and extends our previous conclusions that solitarious locusts undergo a rapid behavioural gregarization upon receiving appropriate stimulation for a few hours that is mediated by serotonin, at the end of which their behaviour is largely indistinguishable from locusts that have been in the gregarious phase their entire lives.

Effect of resveratrol on behavioral performance of streptozotocin-induced diabetic mice in anxiety tests.

The aim of this study was to evaluate with anxiety tests the effect of resveratrol (RSV) on streptozotocin (STZ)-induced diabetic mouse behavioral performance at the second and fourth week of treatment. Confirmed diabetic mice (>250 mg/dl of glucose in blood after STZ injection) were treated with RSV (RDM, n=12) or control treated (DM, n=12) for 4 weeks. DM and RDM were tested in the Open Field Test (OFT) and Elevated Plus Maze (EPM). In the second week of RSV treatment, a higher grooming frequency (P<0.05) and a lower defecation and rearing frequency (P<0.05) were detected in the OFT in the RDM group compared with the DM. There was a higher grooming frequency (P<0.05) and higher percentage of entries in open arms (P<0.05) in the RDM group than in the DM group in the EPM. However, in the fourth week of RSV treatment, the only effect observed was a higher grooming frequency in the RDM group than in the DM group (P<0.05) in the EPM. In conclusion, RSV treatment in diabetic mice provoked anxiolytic-like effects in both tests (OFT and EPM), and these effects were observed in a short time window (2 weeks). It is suggested that RSV may help diabetic animals to adapt to new stressing and anxiety situations and thus to improve their welfare.

한우 육성우의 성별 군집두수에 따른 사양성적, 행동특성 및 혈액성상 비교분석

ABSTRACT This study examined the effects of sex in different group sizes of Hanwoo calves. The growth performance including the mean daily gain, feed conversion rate, behavioral characteristics, and blood parameters in Hanwoo calves were investigated. A total of 54 heads of Hanwoo calves were housed separately at 4 heads per group, 3 heads per group, and 2 heads per group per pen. In the heifer calves, except for those 10 months of age, the growth performance was improved by increasing the group size, which was similar to steer calves (p<0.05). The heifer calves housed in 3 heads group spent more time lying down (p<0.05). The steer calves spent more time standing in the 3 heads group, lying down (2 heads group), and walking (4 heads group). The heifer calves housed in 2 heads group had a lower frequency of drinking, self-grooming, pairwise grooming, and fighting (p<0.05). On the other hand, the steer calves in the 4 heads group had a higher frequency of drinking, rubbing, and fighting (p<0.05). The white blood cell and cortisol were highest in the heifer calves in the 2 heads group (p<0.05).(

Behavioural responses to ectoparasites in pied flycatchersFicedula hypoleuca: an experimental study

Nests of cavity‐nesting birds usually harbor some species of haematophagous ectoparasites that feed on the incubating adults and nestlings. Given the negative impact of ectoparasites on nestlings there will be selection on hosts to reduce parasite infestations through behavioural means. We have experimentally reduced the abundance of all ectoparasites in nests of pied flycatchersFicedula hypoleucato explore both whether there are changes in the frequency and duration of putative anti‐parasite behaviours by tending adults, as well as whether such anti‐parasite behaviours are able to compensate for the deleterious effects that parasites may have on nestlings. Heat treatment of nests substantially decreased the density of ectoparasites, and thereby positively affected nestling growth. The frequency and intensity of female grooming and nest sanitation behaviours during the incubation and nestling periods decreased as a consequence of the experimental reduction of ectoparasite infestation. Although nestlings begged more intensely in infested nests, the experiment had no significant effect on parental provisioning effort. Reduction of parasites resulted in larger nestlings shortly before fledging and increased fledging success. This study shows a clear effect of a complete natural nest ectoparasite fauna on parental behaviour at the nest and nestling growth in a cavity‐nesting bird. Although ectoparasites induce anti‐parasite behaviours in females, these behaviours are not able to fully remove parasite's deleterious effects on nestling growth and survival.

Comparative Study of Aqueous and Ethanolic Leaf Extracts Of Spondias Mombin on Neurobehaviour in Male Rats

Remedies for anxiety and fear have been investigated through both orthodox and traditional medicine; this study compared the effects of chronic administration of graded doses of aqueous and ethanolic extracts of Spondias mombin on anxiety and fear in Albino Wistar rats. Fifty rats of Wistar strain (100-120g body weight) were divided into five major groups A-E with each group made up of ten rats (n=10). Spondias mombin (250, 400,500 and 800mg/kg) were orally administered for 4 weeks before testing. The elevated plus maze was used to assess anxiety behaviour. Following administration of graded doses of aqueous and ethanolic extracts of Spondias mombin for a period of four weeks, decreased anxiety and fear in the albino rats was revealed (p<0.05). The order of the anxiolytic property following these graded dose of administration was; duration and frequency in open arm of the 500mg/kg group was significantly higher (90.2 ± 37.2s & 4.4 ± 1.29/5min respectively) compared to control, and other treatment groups of Spondias mombin (P< 0.05). Duration in closed arm (260.33 ± 15.97s) was significantly lower compared to control. Closed arms frequency with 250mg/kg and 500mg/kg ethanol extract were 3 .83 ± 1.74/5min and 3.16 ± 1.40/5min. The extracts were significantly (P<0.05) lower compared with control (8.67 ± 1.05/5min). However, the 500mg/kg ethanol extract showed a lower frequency. The duration of grooming following four weeks of treatment with 250mg/kg and 500mg/kg ethanol extract of Spondias mombin were 8.68 ± 2.10s and 12. 1 ± 0.001s respectively and these were significantly lower compared to control. Spondias mombin dose-dependently decreased anxiety and fear with significant decrease observed in rats administered with ethanolic extracts of Spondias mombin. Anxiolytic effect is shown by decrease in the frequency of grooming and duration of grooming, decrease in frequency of head dipping and stretch attempt posture (SAP), and a lower frequency of close arm entry by the experimental groups. Ethanolic extract from Spondias mombin produced better behavioral effects with decreased anxiety and fear compared to the aqueous extract and so has a potential as an alternative anxiolytic and sedative agent compared to its aqueous extract.

Inflammatory macrophage phenotype in BTBR T+tf/J mice

Although autism is a behaviorally defined disorder, many studies report an association with increased pro-inflammatory cytokine production. Recent characterization of the BTBR T+tf/J (BTBR) inbred mouse strain has revealed several behavioral characteristics including social deficits, repetitive behavior, and atypical vocalizations which may be relevant to autism. We therefore hypothesized that, asocial BTBR mice, which exhibit autism-like behaviors, may have an inflammatory immune profile similar to that observed in children with autism. The objectives of this study were to characterize the myeloid immune profile of BTBR mice and to explore their associations with autism-relevant behaviors. C57BL/6J (C57) mice and BTBR mice were tested for social interest and repetitive self-grooming behavior. Cytokine production was measured in bone-marrow derived macrophages incubated for 24 h in either growth media alone, LPS, IL-4/LPS, or IFNγ/LPS to ascertain any M1/M2 skewing. After LPS stimulation, BTBR macrophages produced higher levels of IL-6, MCP-1, and MIP-1α and lower IL-10 (p < 0.01) than C57 mice, suggesting an exaggerated inflammatory profile. After exposure to IL-4/LPS BTBR macrophages produced less IL-10 (p < 0.01) than C57 macrophages and more IL-12p40 (p < 0.01) suggesting poor M2 polarization. Levels of IL-12(p70) (p < 0.05) were higher in BTBR macrophages after IFNγ/LPS stimulation, suggesting enhanced M1 polarization. We further observed a positive correlation between grooming frequency, and production of IL-12(p40), IL-12p70, IL-6, and TNFα (p < 0.05) after treatment with IFNγ/LPS across both strains. Collectively, these data suggest that the asocial BTBR mouse strain exhibits a more inflammatory, or M1, macrophage profile in comparison to the social C57 strain. We have further demonstrated a relationship between this relative increase in inflammation and repetitive grooming behavior, which may have relevance to repetitive and stereotyped behavior of autism.

Increased anxiety-related behavior in male and female adult rats following early and late adolescent exposure to 3,4-methylenedioxymethamphetamine (MDMA)

Subsequent behavioral effects in adulthood of daily exposure to MDMA during early or late adolescence were assessed in both male and female rats. From either postnatal day (PND) 35 (early adolescence) or PND45 (late adolescence), PVG/c rats of each sex were exposed via intraperitoneal injections to saline or 10mg/kg MDMA for 10 consecutive days. They were regularly weighed during treatment and again on PND90. At this age, their anxiety-related behavior was determined from frequencies of ambulation, rearing, grooming, defecation and occupancy of the center and corners of an open field, as well as entries into and time spent in the light compartment of a light–dark box. Spatial and working memories were assessed by preferences for a novel Y-maze arm, and by recognition of a novel object. MDMA-exposed rats gained less weight during treatment than saline controls but were heavier on PND90 depending on their sex or age when treated. As shown by decreased open-field ambulation (for males only) and increased defecation plus fewer entries into the light compartment of the light–dark box and entries into both arms of a Y maze, MDMA exposure increased adult anxiety-related behavior particularly for rats treated during late adolescence. There was no evidence of any effects on either spatial or working memory.

Integration into the dairy cow herd: Long-term effects of mother contact during the first twelve weeks of life

The objective of this study is to investigate the long-term effects of mother rearing on the ability to cope with the challenge of integration into the cow herd shortly before first parturition. Four groups of heifers with different levels of contact with their mothers during the first twelve weeks of life were compared. Two rearing groups were fed via an automatic milk feeder two (A2, n=5) or six times (A6, n=5) a day. The animals in these groups were compared to two treatment groups that were either kept separate from the cow herd and with limited contact with their mothers (M2, n=9) or permanent access to the herd and their mothers through selection gates (MP, n=7). At the age of 25±0.2months, heifers were integrated individually into the cow herd and observed for 33h. Social and other behaviour of each heifer was recorded by continuous behaviour sampling, and the identity of the nearest neighbour was determined by time sampling every 5min. Additionally, faecal samples were taken for measurement of adrenocortical activity. For statistical analysis ANOVA was performed with treatment and breed as fixed factors and herd size, except for social behaviour as covariate. For post hoc testing, heifers were allocated to groups according to contact with the mother (M2 and MP; mother) i.e. suckling by the mother compared to automatic feeding (A2 and A6; automat) and according to contact with the herd (MP; permanent suckling vs. M2, A2, A6; no herd). The treatment groups tended to differ in the frequency of self grooming (p=0.102), with mother-heifers tending to self-groom more often than automat-heifers (p=0.109). Permanent suckling-heifers performed self-grooming more often than no herd-heifers (p=0.048). Concerning social behaviour, the treatment groups tended to differ in submissive behaviour (p=0.062), with mother-heifers being submissive more often than automat-heifers (p=0.023) and permanent suckling-heifers more often than no herd-heifers (p=0.055). The increase in the concentration of faecal cortisol metabolites after the first two days of integration tended to be different between the treatment groups (p=0.088). In our nearest neighbour analysis, one MP-heifer and one M2-heifer could clearly identify their mothers in a herd of 50 cows after 2years of separation (p<0.05, over chance level). This suggests that rearing with contact with the mother in the first twelve weeks, even if very limited, may have an effect on later behaviour and may lead to possibly enhanced social skills in dairy heifers.

Analysis of emotionality and locomotion in radio-frequency electromagnetic radiation exposed rats

In the current study the modulatory role of mobile phone radio-frequency electromagnetic radiation (RF-EMR) on emotionality and locomotion was evaluated in adolescent rats. Male albino Wistar rats (6-8 weeks old) were randomly assigned into the following groups having 12 animals in each group. Group I (Control): they remained in the home cage throughout the experimental period. Group II (Sham exposed): they were exposed to mobile phone in switch-off mode for 28 days, and Group III (RF-EMR exposed): they were exposed to RF-EMR (900 MHz) from an active GSM (Global system for mobile communications) mobile phone with a peak power density of 146.60 μW/cm(2) for 28 days. On 29th day, the animals were tested for emotionality and locomotion. Elevated plus maze (EPM) test revealed that, percentage of entries into the open arm, percentage of time spent on the open arm and distance travelled on the open arm were significantly reduced in the RF-EMR exposed rats. Rearing frequency and grooming frequency were also decreased in the RF-EMR exposed rats. Defecation boli count during the EPM test was more with the RF-EMR group. No statistically significant difference was found in total distance travelled, total arm entries, percentage of closed arm entries and parallelism index in the RF-EMR exposed rats compared to controls. Results indicate that mobile phone radiation could affect the emotionality of rats without affecting the general locomotion.

Mo1860 Identification of Kappa Opioid Receptors on Colonic Sensory Nerves and Their Up-Regulation in a Mouse Model of Chronic Visceral Hypersensitivity

Background: Inflammatory bowel disease (IBD) is characterized by chronic inflammation of the gastrointestinal tract. This relapsing condition is often associated with debilitating abdominal pain, which in some cases can persist throughout quiescent stages of the disease. The regulatory mechanisms involved in central sensitization and peripheral neuroplasticity in the context of IBD-related visceral pain remains elusive. A growing body of evidence suggests a role for the transient receptor potential vanilloid 1 (TRPV1) in visceral hypersensitivity. TRPV1 is expressed in sensory dorsal root ganglion (DRG) neurons and is directly involved in nociception. Previous studies have demonstrated that TRPV1-deficient mice experience reduced thermal hyperalgesia during inflammation, thus suggesting a role for TRPV1 in inflammatory pain. The objective of the present study was therefore to investigate the role of TRPV1 in visceral pain in the dextran sulfate sodium (DSS) murine model of colitis. Methods: Mice were given DSS in drinking water for 7 days, after which spontaneous visceral pain was assessed using the non-invasive, animal behavior recognition system LABORAS. Control and DSS-treated mice were then sacrificed and colon-innervating DRGs collected for quantitative PCR, immunostaining, and neuronal dissociation. In Vitro studies were performed with human neuroblastoma NG108 cells. Results: DSS-treated mice showed reduced mobility and frequency of grooming and climbing, which likely reflect spontaneous visceral pain. Remarkably, while controls cells showed very few processes, dissociated DRG neurons isolated from DSS-treated mice displayed extensive neurite outgrowth after 24 h in culture. Immunocytochemistry later revealed TRPV1 expression along the entire length of these axons. These results are supported by In Vitro data demonstrating that exposure to a mixture of proinflammatory cytokines (bradykinin, histamine, and serotonin) induces neurite outgrowth and TRPV1 membrane trafficking in TRPV1-transfected neuronal NG108 cells. Finally, PCR analysis demonstrated that the neuronal morphological changes observed in DSS-treated animals were associated with a significant decrease in the expression of the small Rho GTPase RhoA and Rho kinase, both of which are known to modulate neurite outgrowth. Conclusion: These results demonstrate that DSS-colitis induces changes in neuronal morphology and modulation of TRPV1 trafficking, which may play a role in visceral hypersensitivity in the context of gastrointestinal inflammatory disorders. Current experiments using pharmacological inhibitors of the RhoA/Rho kinase signaling axis and TRPV1deficient animals will provide important insights into the exact role of TRPV1 in IBD-related visceral hypersensitivity and perhaps identify new targets for the treatment of chronic pain in these patients.

Mo1859 Visceral Pain Correlates With Neuronal Outgrowth and Modulation of TRPV1 Trafficking in Dorsal Root Ganglion Neurons in a Murine Model of Colitis

Background: Inflammatory bowel disease (IBD) is characterized by chronic inflammation of the gastrointestinal tract. This relapsing condition is often associated with debilitating abdominal pain, which in some cases can persist throughout quiescent stages of the disease. The regulatory mechanisms involved in central sensitization and peripheral neuroplasticity in the context of IBD-related visceral pain remains elusive. A growing body of evidence suggests a role for the transient receptor potential vanilloid 1 (TRPV1) in visceral hypersensitivity. TRPV1 is expressed in sensory dorsal root ganglion (DRG) neurons and is directly involved in nociception. Previous studies have demonstrated that TRPV1-deficient mice experience reduced thermal hyperalgesia during inflammation, thus suggesting a role for TRPV1 in inflammatory pain. The objective of the present study was therefore to investigate the role of TRPV1 in visceral pain in the dextran sulfate sodium (DSS) murine model of colitis. Methods: Mice were given DSS in drinking water for 7 days, after which spontaneous visceral pain was assessed using the non-invasive, animal behavior recognition system LABORAS. Control and DSS-treated mice were then sacrificed and colon-innervating DRGs collected for quantitative PCR, immunostaining, and neuronal dissociation. In Vitro studies were performed with human neuroblastoma NG108 cells. Results: DSS-treated mice showed reduced mobility and frequency of grooming and climbing, which likely reflect spontaneous visceral pain. Remarkably, while controls cells showed very few processes, dissociated DRG neurons isolated from DSS-treated mice displayed extensive neurite outgrowth after 24 h in culture. Immunocytochemistry later revealed TRPV1 expression along the entire length of these axons. These results are supported by In Vitro data demonstrating that exposure to a mixture of proinflammatory cytokines (bradykinin, histamine, and serotonin) induces neurite outgrowth and TRPV1 membrane trafficking in TRPV1-transfected neuronal NG108 cells. Finally, PCR analysis demonstrated that the neuronal morphological changes observed in DSS-treated animals were associated with a significant decrease in the expression of the small Rho GTPase RhoA and Rho kinase, both of which are known to modulate neurite outgrowth. Conclusion: These results demonstrate that DSS-colitis induces changes in neuronal morphology and modulation of TRPV1 trafficking, which may play a role in visceral hypersensitivity in the context of gastrointestinal inflammatory disorders. Current experiments using pharmacological inhibitors of the RhoA/Rho kinase signaling axis and TRPV1deficient animals will provide important insights into the exact role of TRPV1 in IBD-related visceral hypersensitivity and perhaps identify new targets for the treatment of chronic pain in these patients.

Anxiolytic effect of clonazepam in female rats: Grooming microstructure and elevated plus maze tests

Grooming behavior is an adaptation to a stressful environment that can vary in accordance with stress intensity. Direct and indirect GABAA receptor agonists decrease duration, frequency, incorrect transitions and uninterrupted bouts of grooming. Hormonal variation during the different phases of the estrous cycle of female rats also changes the grooming behavior. It is known that GABAA agonists and endogenous hormones change anxiety-like behaviors observed in the elevated plus maze test, a classical animal model of anxiety. This study was designed to determine the anxiolytic effect of clonazepam in female rats in different estrous phases and to correlate anxiety behaviors in the elevated plus maze and grooming microstructure tests. Our results show that female rats displayed higher anxiety-like behavior scores during the estrus and proestrus phases in the elevated plus maze and that clonazepam (0.25mg/kg; i.p.) had an anxiolytic effect that was independent of the estrous phase. Grooming behaviors were higher in the proestrus phase but were decreased by clonazepam administration, independent of the estrous phase, demonstrating the anxiolytic effect of this drug in both animal models. Grooming behaviors were moderately associated with anxiolytic-like behaviors in the elevated plus maze test. Here, we describe the anxiolytic effect of clonazepam and the influence of estrous phase on anxiety. Moreover, we show that the grooming microstructure test is a useful tool for detecting anxiolytic-like behaviors in rats.

In Vivo Manganese Exposure Modulates Erk, Akt and Darpp-32 in the Striatum of Developing Rats, and Impairs Their Motor Function

Manganese (Mn) is an essential metal for development and metabolism. However, exposures to high Mn levels may be toxic, especially to the central nervous system (CNS). Neurotoxicity is commonly due to occupational or environmental exposures leading to Mn accumulation in the basal ganglia and a Parkinsonian-like disorder. Younger individuals are more susceptible to Mn toxicity. Moreover, early exposure may represent a risk factor for the development of neurodegenerative diseases later in life. The present study was undertaken to investigate the developmental neurotoxicity in an in vivo model of immature rats exposed to Mn (5, 10 and 20 mg/kg; i.p.) from postnatal day 8 (PN8) to PN12. Neurochemical analysis was carried out on PN14. We focused on striatal alterations in intracellular signaling pathways, oxidative stress and cell death. Moreover, motor alterations as a result of early Mn exposure (PN8-12) were evaluated later in life at 3-, 4- and 5-weeks-of-age. Mn altered in a dose-dependent manner the activity of key cell signaling elements. Specifically, Mn increased the phosphorylation of DARPP-32-Thr-34, ERK1/2 and AKT. Additionally, Mn increased reactive oxygen species (ROS) production and caspase activity, and altered mitochondrial respiratory chain complexes I and II activities. Mn (10 and 20 mg/kg) also impaired motor coordination in the 3rd, 4th and 5th week of life. Trolox™, an antioxidant, reversed several of the Mn altered parameters, including the increased ROS production and ERK1/2 phosphorylation. However, Trolox™ failed to reverse the Mn (20 mg/kg)-induced increase in AKT phosphorylation and motor deficits. Additionally, Mn (20 mg/kg) decreased the distance, speed and grooming frequency in an open field test; Trolox™ blocked only the decrease of grooming frequency. Taken together, these results establish that short-term exposure to Mn during a specific developmental window (PN8-12) induces metabolic and neurochemical alterations in the striatum that may modulate later-life behavioral changes. Furthermore, some of the molecular and behavioral events, which are perturbed by early Mn exposure are not directly related to the production of oxidative stress.