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Biomedical subjects

E Alleva

Publications and source records attributed to E Alleva.

At least 37 records · Page 2Linked to original sources

Prolonged perinatal exposure to AZT affects aggressive behaviour of adult CD-1 mice.

RATIONALE: AZT is commonly administered to seropositive women and their neonates to prevent mother-to-child transmission of HIV. Recently, animal studies performed in monkeys and rodents have revealed that pre- and/or perinatal exposure to AZT induces age- and sex-dependent behavioural alterations in the offspring, possibly resulting from an action of this drug on CNS targets. Long-term effects of prenatal AZT treatment on social/aggressive behaviour of adult male mice have been previously described. Specifically, AZT has been shown to induce selective changes in the offensive components of agonistic interactions. OBJECTIVE: The aim of the present study was to extend previous findings, analysing the long-term effects of a more prolonged AZT exposure on intraspecific male mice agonistic behaviour. METHODS: AZT was given orally twice daily to pregnant CD- mice. The dosage selected for AZT was 160 mg/kg. Saline solution (0.9% NaCl) was used as vehicle. Starting on postnatal day (PND) 60 isolated males underwent five 15-min repeated encounters with an opponent of the same age and strain isolated for the same amount of time. Furthermore, a locomotor activity test (PND 67) and a hot-plate test (52 +/- 0.1 degrees C) (PND 74) were performed to assess AZT effects on, respectively, general activity and pain sensitivity. RESULTS: AZT perinatal exposure reduced attack behaviour of adult mice, while increasing the likelihood of them behaving as subordinates. Furthermore, long-term effects of AZT treatment on pain sensitivity were found in the hot-plate test, with AZT mice showing higher pain thresholds than controls. CONCLUSIONS: Overall, these data indicate that perinatal exposure to drugs such as AZT exerts selective effects on the developing CNS, resulting in long-term behavioural disturbances. Future studies will need to address the issue of the specific mechanisms underlying these effects.

Aggression↗

Effects of prenatal AZT+3TC treatment on open field behavior and responsiveness to scopolamine in adult mice.

Treatment of pregnant seropositive women and their neonates with the nucleoside analogs (reverse transcriptase inhibitors) zidovudine (AZT), lamivudine (3TC) and their combination has become a standard of care in industrialized countries to prevent transmission of the HIV-1 virus. Animal studies indicated limited but significant behavioral changes in AZT or 3TC-prenatally exposed offspring, whereas data on the potential neurobehavioral outcomes of AZT+3TC combination are still lacking. The aim of the present study was to assess in mice prenatally exposed to AZT+3TC the functional state of cholinergic muscarinic neuroregulation at adulthood. Pregnant CD-1 mice received per orem twice daily AZT+3TC (160 and 500 mg/kg, respectively) or vehicle solution (NaCl 0.9%) from gestational day (GD) 10 to delivery (GD 19). Locomotor activity, exploratory behavior and responsiveness to the muscarinic cholinergic blocker scopolamine (2 mg/kg) were analyzed at adulthood (PND 70) in offspring of both sexes in an open field test. Results indicated that prenatal AZT+3TC exposure does not influence responsiveness to the muscarinic cholinergic antagonist as measured by analysis of the drug's effects on locomotor and exploratory activity and different behavioral items. However, AZT+3TC-treated mice displayed higher frequency of rearing, and lower frequency and duration of self-grooming behavior, consistent with an effect on dopaminergic neurotransmission. However, this would need confirmatory experiments.

Animals↗

Learning performances, brain NGF distribution and NPY levels in transgenic mice expressing TNF-alpha.

Tumor necrosis factor-alpha (TNF-alpha) is a cytokine involved in a variety of neurobiological activities including changing behavior and regulation of both neurotrophin and neuropeptide levels. In this study we used two lines of transgenic mice overexpressing brain TNF-alpha characterized by neurological deficits (line Tg6074) or phenotypically normal (line TgK3). We analyzed whether or not impairments in learning and memory processes due to TNF-alpha overexpression were associated with changes in endogenous brain NGF, NPY and beta-amyloid. The results indicate that full TNF-alpha transgene expression disrupted the learning capabilities of transgenic mice (both Tg6074 and TgK3). NGF decreased in the hippocampus of both transgenic mice whereas hippocampal NPY slightly potentiated in Tg6074. The decrease in NGF is correlated with deficits in spatial learning and memory whereas inflammation in the brain of Tg6074 could be responsible of the hippocampal increase in NPY. As a whole, these results show that transgenic mice overexpressing TNF-alpha in the brain represent a useful model for studying neuronal degeneration and brain inflammatory processes.

Amyloid beta-Peptides↗

Serum NGF levels in children and adolescents with either Williams syndrome or Down syndrome.

The neurotrophin nerve growth factor (NGF) is a major regulator of peripheral and central nervous system development. Serum NGF was measured in normally developing control children (n=26) and in individuals affected by congenital syndromes associated with learning disability: either Williams syndrome (WS; n=12) or Down syndrome (DS; n=21). Participants were assessed at three distinct developmental stages: early childhood (2 to 6 years), childhood (8 to 12 years), and adolescence (14 to 20 years). A sample was taken only once from each individual. Serum NGF levels were markedly higher in participants with WS, than DS and control participants. In addition, different developmental profiles emerged in the three groups: while in normally developing individuals NGF levels were higher in early childhood than later on, children with WS showed constantly elevated NGF levels. When compared to control participants, those with DS showed lower NGF levels only during early childhood. Neuropsychological assessment confirmed previously reported differences among the three groups in the development of linguistic/cognitive abilities. Some features of individuals with WS, such as hyperacusis and hypertension, could be related to high-circulating NGF levels.

Adolescent↗

Important hints in behavioural teratology of rodents.

The paper deals with the most important items regarding the improvement of quality of experimental procedures when testing drug effects on behaviour and development of commonly-used rodent species. Current-used test procedures for immature and adult rodents exposed early developmentally are briefly described and recent advances and difficulties in their hands-on interpretation are highlighted. Comparability of measures in human and animals for drug-effect assessment is also shortly discussed. It is then stressed that studies on rodents carried out in seminaturalistic and naturalistic settings may offer a highly profitable direction for future research in behavioural teratology and toxicology. A final paragraph is dedicated to the bioethical aspects arisen from the use of large number of rodents subjects in behavioural testing.

Animals↗

Long-term effects of prenatal 3'-azido-3'-deoxythymidine (AZT) exposure on intermale aggressive behaviour of mice.

RATIONALE: AZT treatment of seropositive pregnant women and their neonates has been widely used due to its effectiveness in reducing vertical transmission of HIV, but medium- and long-term effects of AZT on neurobehavioural development and adult responding are still poorly described. OBJECTIVE: The aim of the present study was to evaluate the long-term effects of prenatal AZT treatment on aggressive behaviour of adult male mice. METHODS: Pregnant CD-1 mice were given saline vehicle, 0.4, or 0.8 mg/ml AZT in their drinking water from gestation day 10 to delivery. Social-aggressive types of interaction were assessed in their male offspring following a 4-week isolation period. Two groups of subjects were used, each undergoing a different type of test: test 1 consisted of a single 20-min encounter with an isolated same-strain opponent on postnatal day (PND) 90, while in test 2 (PND 150) subjects were paired for 10 min for 5 consecutive days with a non-isolated opponent. RESULTS: Slight changes in both aggressive and defensive components of the male-specific agonistic pattern were evident only in test 1, AZT mice displaying a limited increase of aggressive behaviour compared to their controls. CONCLUSIONS: Although the long-term effects of prenatal AZT on social behaviour are limited, they may be of some relevance for paediatricians in order to plan a follow-up of infants, children and adolescents exposed in utero to antiretroviral drugs.

Aggression↗

Behavioural effects of endocrine disrupting chemicals on laboratory rodents: statistical methodologies and an application concerning developmental PCB exposure.

Appropriate behavioural tests and adequate statistical tools may help to establish the ED properties of a given compound by pointing out the alterations of selected behavioural endpoints. Frequently, laboratory collected data consist of frequencies and/or durations of specific items, and the analysis of variance (ANOVA) technique is performed to assess whether the investigated factors affect these behavioural endpoints. Moreover, when numerous aspects of behaviour are investigated simultaneously, Principal Component Analysis (PCA), a multivariate technique, may be very useful to reduce the overwhelming number of correlated original variables to a few orthogonal artificial variables (factors). Continuous Time Markov Chain (CTMC) models may be applied to analyse the time structure of a behavioural pattern when data consist of sequences of events and the time points at which they occur. Moreover, the Cox Proportional Hazard Model, a methodology originally developed for the analysis of failure time data, may help to evidence the effects of a given treatment on behavioural sequences when the assumptions of CTMC models are not fully satisfied. Analyses on data from mice of the outbred CD-1 strain (controls in a study of toxicity and exposed to PCB during development) are presented as examples to show how adequate statistical analyses and appropriate behavioural tests may reveal relevant effect of treatments otherwise not easily detected.

Animals↗

Song behavior, NGF level and NPY distribution in the brain of adult male zebra finches.

The aim of the present study was to investigate the role of nerve growth factor (NGF) and neuropeptide Y (NPY) in the higher vocal center (HVC) on singing behavior of adult male zebra finches. The results of our studies show: (a) that NGF is present in the brain of these birds and it is higher in the HVC than in the other neostriatal tissues; (b) that exogenous administration of NGF or NGF-antibody had no discernible effect on singing behavior; and (c) that NGF enhances the NPY immunoreactivity in neurons and fibers localized in HVC and other areas of the neostriatum and hippocampus whereas anti-NGF decreased NPY stained cells in the hippocampus. These studies indicate that NGF is produced in the brain of zebra finch and that it plays a role in the regulation of NPY.

Animals↗

Ultrasonic vocalizations elicit orienting and associative reactions in preweanling mice.

On postnatal days (PND) 12 and 13, 90 male Swiss CD-1 mice were tested for orientation to 3 intensities of recorded ultrasounds while climbing an inclined wire grid surface. Motor responses and vocalization to replayed ultrasounds (55-75 kHz) of 20-, 40-, and 60-dB SPL indicated an intensity dependence. In Experiment 2, 138 pups were exposed to either contingent or noncontingent pairings of recorded ultrasounds of 55-75 kHz, averaging 40 dB, and mild inescapable footshocks, or taped vocalizations or footshocks only on PND 12, 14, or 16. At PND 18, subjects were tested for passive avoidance following exposure to the taped ultrasounds only upon entry into the dark side of a black-white compartment. Results suggested only overall, nonspecific effects of pretreatment to elicit responses antagonistic to motor activity. In Experiment 3, 36 pups at PND 15 were tested for passive avoidance with the ultrasound recordings of 40- or 80-dB onset upon entry to the dark compartment; a third group had no ultrasound exposure. A significant intensity effect confirmed that the ultrasounds had prepotent properties.

Animals↗

Limited changes in handedness and morphine reactivity in CD-1 mice after pre- and postnatal ozone exposure.

Outbred CD 1 mice were either not exposed (control group) or exposed to ozone (O3) (0.3, 0.6, or 0.9 ppm), during foetal and neonatal life until the time of weaning (postnatal day (PND) 26). On PND 70 the subjects were tested for handedness using a paw preference task assessing both the animals' capability to reach a food pellet in a feeding tube and the individual preference for the use of one of the other forepaw. O3 exposure did not affect the animals' capability to learn the task but caused changes in handedness. Specifically, females exposed to the intermediate O3 concentration showed a reduced preference for the right paw than both their same-sex controls and 0.6 ppm males. On PND 100, mice underwent a hot plate test after IP treatment by either saline or morphine HCl (10 mg/kg). The results were generally in the direction of reduced drug sensitivity after exposure to the highest concentration. The evidence for this effect was more robust in the case of an organised avoidance response (wall-rearing) than in the case of a reflexive response (limb withdrawal); in the case of the former, latency data showed an effect on both males and females while frequency data showed an effect only in females. Overall, the O3 effects are suggestive of subtle CNS changes affecting mouse behavioural responses.

Animals↗

Effects of prenatal zidovudine treatment on learning and memory capacities of preweanling and young adult mice.

The present study analyzed the short and long-term effects of prenatal zidovudine (AZT) exposure on learning and memory capacities of CD-1 mice. Two tasks normally used in rodents were used, namely a passive avoidance step-through task and a Morris navigation task. AZT (0, 0.4, and 0.8 mg/ml) was administered via drinking water to pregnant CD-1 females from day 10 of gestation to delivery. Data on reproductive performance, such as gestation length, litter size, and pup mortality were collected. Avoidance learning in the offspring was tested on postnatal day (PND) 15, while spatial learning performances in the Morris water maze were obtained on PND 45. Retention of the passive avoidance response was mildly impaired in the offspring exposed to the 0.8 mg/ml AZT solution, whereas spatial learning on PND 45 was unaffected.

Animals↗

[Williams syndrome].

Williams syndrome (WS) is a rare (2-5/100,000) genetic human disorder characterised by a typical facies and mental retardation with a deficit in the visuospatial cognitive function and a relative preservation of linguistic abilities in general, and spoken language in particular. This syndrome also includes morphological anomalies, metabolic functional impairments, and likely deficits in the pattern of brain ontogenesis. The genetic basis of WS, recently identified, are presented. A cognitive profile of the WS individuals is defined and compared to Down syndrome (DS) and autism cognitive profiles. Neuroanatomical features of WS, including a reduction in brain volume, preservation of cerebellum and frontal lobes, and a reduction of posterior cortical systems, are described. The possible role of NGF (nerve growth factor)--a neurotrophin involved in the development of brain cholinergic systems and the associated behavioural functions--in the aetiology of the typical mental retardation of WS patients, is critically discussed. Future research avenues, including the identification of potential neurobiological markers in order to precociously diagnose this syndrome, are reviewed.

Biomarkers↗

Infection with Schistosoma mansoni in mice induces changes in nociception and exploratory behavior.

In this study, CD-1 mice were infected percutaneously with 1600 cercariae of Schistosoma mansoni and their pain sensitivity and exploratory behavior were analyzed in well-standardized tests (hot-plate, hole-board, open-field, novel object investigation and black/white box). Schistosome infection produced body weight reduction, increased analgesia, induced changes in the number of fecal pellets emitted during the hole-board and the black/white tests, induced decreased locomotion in the open-field, decreased sniffing, rearing, wall-rearing and time spent in exploratory activity. The infection also lengthened the latency time to the first transition from the white into the black compartment in the black/white box, index of enhanced anxiety. The present findings indicate that the analgesia is one of the main effects of the disease suggesting that schistosome infection induces maladaptive response in exploratory behavior and in locomotor activity of the host associated with altered motivational and attentional levels. Furthermore, though mouse behavioral changes appear to be similar to those observed in parasite/host systems where the changes are supposed to be adaptive for the parasite, in the case of Schistosoma/mouse system, the changes in host behavior resulted to be not adaptive for the parasite.

Animals↗

Behavioral effects of peripheral interleukin-1 administration in adult CD-1 mice: specific inhibition of the offensive components of intermale agonistic behavior.

Peripheral administration of interleukin-1beta (IL-1beta) in rodents reduces exploratory behavior in a novel environment while decreasing social investigation of a juvenile conspecific. In this study we wanted to test the effects of peripherally administered IL-1beta on another aspect of the mouse social repertoire, namely intraspecific fighting towards an adult male intruder. In the first experiment, sickness behavior induced by IL-1beta (1 microg/mouse) in adult CD-1 mice was assessed by direct observation of behavioral changes following placement into a novel environment. Three hours after injection, subjects were individually introduced for 20 min in a cage with clean sawdust and a number of behavioral items recorded. Blood samples were collected at the end of the testing session. Body temperature was measured right before, 1 h and 3.5 h following injection. In IL-1beta treated mice, exploration (assessed by measuring duration and frequency of Wall Rearing and Rearing behaviors) was nearly totally suppressed, while duration and frequency of behaviors such as Grooming, Bar Holding, and Digging were also markedly reduced. Administration of IL-1beta significantly elevated CORT secretion above basal levels and, as previously reported for mice, induced hypothermia (about 2 degrees C). In the second experiment, we assessed mice receiving IL-1beta (0.25; 0.5 or 1 microg/mouse or saline solution) in a social context. Three hours after injection, subjects were placed into a neutral cage for 20 min with a non-injected adult male conspecific and aggressive behavior scored. Overall, IL-1beta administration affected the social repertoire of treated mice in a dose-dependent fashion. Specifically, agonistic components of aggressive behavior were nearly totally suppressed, while the defensive elements, such as Upright Defensive posture, Upright Submissive posture, Crouching, or Flee were not affected by IL-1beta. Overall these data support the notion that sickness behavior induced by IL-1beta administration represents an organized behavioral strategy and is not an aspecific response to an illness-type of condition.

Agonistic Behavior↗

Exploratory and displacement behavior in transgenic mice expressing high levels of brain TNF-alpha.

Studies reported recently have shown that tumor necrosis factor-alpha (TNF-alpha) a cytokine released by macrophages and monocytes plays a key role in inflammatory processes and immune and neuro-endocrine regulation. TNF-alpha is also produced in the central nervous system (CNS). However, the role of this cytokine in the CNS is largely unknown, although evidence indicates that it is involved in various neurobehavioral manifestations. Using transgenic mice expressing high amounts of murine TNF-alpha transgene in the neurons of the CNS, we investigated the stereotyped, exploratory, and displacement activities in the hole-board and black/white box. Transgenic mice and their normal control littermates were hybrids of the CBA x C57BL/6 genetic backgrounds and were obtained by backcrossing the CBA x C57BL/6 founder female and her progeny with F1 hybrid mates. Transgenic mice did not show changes in the stereotyped behavior on the hole-board, but they displayed several alterations in the exploratory activities both in the hole-board and black/white box. Transgenic mice also exhibited an increase in grooming when exposed to a highly unfamiliar environmental stimuli in the black/white box. The study suggests that supranormal endogenous TNF-alpha in the brain affects the behavioral responses to stressful conditions.

Animals↗

Ultrasonic vocalizations by infant laboratory mice: a preliminary spectrographic characterization under different conditions.

During the first 2 to 3 weeks of life, isolated neonatal mice emit ultrasonic vocalizations, with various conditions such as hypothermia or olfactory or tactile stimulation eliciting this behavior. Although it is known that pup vocalizations stimulate prompt expression of maternal behavior, the communicative role of infant ultrasonic calls is still a matter of investigation. A fine-grained spectrographic analysis of ultrasonic calls emitted by pups exposed to different conditions was performed. Forty 8-day-old outbred CD-1 mice (Mus musculus) were isolated from their mothers and littermates and randomly exposed to one of the following conditions: (a) odor from the nest, (b) social isolation, (c) low temperature-isolation, (d) tactile stimulation, or (e) odor from a conspecific adult male. Upon consideration of the spectrogram typology and emission frequency interval, it appears that the conditions under which vocalizations are emitted influence the sound characteristics of call production.

Analysis of Variance↗