Editorial for Brian Sciences Special Issue “Epidemiology of ASD Services: Unmet Need, Barriers and Innovative Solutions”

We are very honoured by the collaboration we had with the editorial staff of Brain Sciences for the realization of the special issue “Epidemiology of ASD Services: Unmet Need, Barriers and Innovative Solutions” [...]

The Impact of Health and Social Services on the Quality of Life in Families of Adults with Autism Spectrum Disorder (ASD): A Focus Group Study

Background: Autism spectrum disorder (ASD) is a complex developmental condition that affects the whole family. The gap between childrens’ needs and their satisfaction, especially regarding what concerns the presence of social and healthcare services, is still a source of burden, particularly after the transition to adulthood. Our study aimed to gather a comprehensive view on how parents of adults with ASD perceive (and interact with) health and social services, and how the provision of care impacts family quality of life with the aim to advise ASD intervention programs. The goal is to identify specific areas of change useful to influence autism intervention strategies so that they more effectively meet the needs of young people with autism and their families. Methods: We conducted two focus groups with parents of young adults with ASD. A semi-structured focus group methodology was adopted. The QoL conceptual framework guided data collection and analysis as part of a directed theory-driven content analysis approach. Results: The lack of structured care pathways and the low level of integration of different services were the main limits reported by parents during the focus group, while a shared positive perception of the experience conducted together as caring families emerged. Conclusions: The experience here reported claims for a greater role of the institutions in order to facilitate the building of networks that are really inclusive for persons with autism in society and to support the implementation of innovative solutions for the welfare system. Furthermore, parents stressed the need for the provision of support to the family.

Selective reduction in the expression of type-1 metabotropic glutamate receptors in the hippocampus of adult rats born by caesarean section

Perinatal hypoxia causes long-term neurobiological consequences, including alterations in mechanisms of activity-dependent synaptic plasticity and cognitive dysfunction. Changes in neurotransmitter receptors have been associated with these alterations, but little is known on how early hypoxia influences the expression and function of metabotropic glutamate (mGlu) receptors in adult life. This is an important issue because mGlu receptors are implicated in mechanisms of synaptic plasticity. Here, we examined the expression of mGlu1, mGlu5, and mGlu2/3 receptor subtypes in the hippocampus, nucleus accumbens, prefrontal cortex, and dorsal striatum in 6-month old Wistar rats (a) born by vaginal delivery; (b) born by caesarean section; and (c) born by caesarean section followed by 20 min of asphyxia. Unexpectedly, we found a large reduction of mGlu1α protein levels in the hippocampus of rats born by caesarean section regardless of the presence of asphyxia. No changes in mGlu1α receptor protein levels were found in the other brain regions. Levels of mGlu5 and mGlu2/3 receptors and levels of GluA2/3 and GluN1 subunits of AMPA and NMDA receptors did not differ among the three groups of rats in any brain region. These results are consistent with previous findings showing that changes in mGlu1 receptors occur within the epigenetic programming caused by early-life events.

New mode of care. Value and limit of the person-centered care planning for people with mental disability

The huge increase of people with mental and intellectual disability worldwide, and the advocacy capacity achieved by these patients, which culminated in the Convention on the Rights of Persons with Disabilities (CRPD), came along the shifts in the way governments deliver public services. In particular, in the last decades, many countries examined how to provide a person with disabilities an acceptable social functioning, improve wellbeing, according to the principles of equity, solidarity and participation. A new political and social-health model was born, called "welfare community", users are protagonists of their health project and the resources put in place assume an investment character on the community and its economic development. Personalisation of social and health services is also considered in many countries as a "new mode of care", although in different forms depending on financial aspect and recipients. The present article is a narrative review that examines and summarize international research and non-research material to survey the different implementation strategies of personalisation in different countries, with a special focus on Italy, in attempting to provide conceptual clarity about this topic in terms of opportunities and pitfalls.

Epidemiology of Autism Spectrum Disorders: A Review of Worldwide Prevalence Estimates Since 2014

The prevalence of Autism Spectrum Disorder (ASD) has increased dramatically in recent decades, supporting the claim of an autism epidemic. Systematic monitoring of ASD allows estimating prevalence and identifying potential sources of variation over time and geographical areas. At present, ASD prevalence estimates are available worldwide, coming either from surveillance systems using existing health and educational databases or from population studies specifically performed. In the present article, we present a review of the ASD prevalence estimates published since 2014. Data confirm a high variability in prevalence across the world, likely due to methodological differences in case detection, and the consistent increase of prevalence estimates within each geographical area.

Nature-Based Interventions for Mental Health Care: Social Network Analysis as a Tool to Map Social Farms and their Response to Social Inclusion and Community Engagement

Social farming represents a hybrid governance model in which public bodies, local communities, and economic actors act together to promote health and social inclusion in rural areas. Although relational variables are crucial to foster social farm performance, the relational system in which farms are embedded has still not been fully described. Using social network analysis, here we map the nature of the links of a selected sample of social farms operating in Northern Italy. We also explore possible network variations following specific actions taken to potentiate local social farming initiatives. The results show a certain degree of variability in terms of the extension and features of the examined networks. Overall, the actions taken appear to be significant to enlarge and diversify farms' networks. Social farming has the potential to provide important benefits to society and the environment and to contrast vulnerability in rural areas. Being able to create social and economic networks of local communities, social farming may also represent an innovative way to respond to the cultural shift from institutional psychiatry to community-based mental health care. This study emphasizes the critical role played by network facilitation in diversifying actors, promoting heterogeneous relationships, and, in turn, system complexity.

Health issues and informal caregiving in Europe and Italy

Informal caregivers are the unpaid persons who take care of a not self-sufficient family member, due to old age or chronic illness or disability. As in all the European countries, the demand for informal cares is further increased as a result of the ageing societies and the social and political fallout of informal caregiving is a very current and important issue. We have overviewed some international scientific literature, with the aim of understanding the key research objectives to be firstly pursued to address this problem. In particular, we focused on the psycho-physical health differences in informal caregivers, subjected to long lasting load and prolonged stress, as compared to non caregiver persons. We also underlined the relationship between caregiver health differences and stress, gender type, kind of the care recipient (autism) and social and political situation in Europe and Italy. The collected data indicate the necessity to prevent caregiver psychological and physical health by appropriate laws, especially supporting women, often most involved in care activities.

Are touch screen technologies more effective than traditional educational methods in children with autism spectrum disorders? A pilot study

Applied Computer technologies can address the needs of individuals with autism spectrum disorders (ASD). Data on the efficacy of assistive technology in ASD is limited, and its effectiveness in supporting and facilitating skill acquisition in this specific population must be still demonstrated. 63 Italian ASD subjects underwent learning activities administered by cardboards or a touch screen support. The support preference was evaluated in a choice trial, and quantitative analysis was performed on items regarding communication and challenging behaviours. Touch devices are attractive especially for males without intellectual disability and a lower communication and cooperation behaviours with the use of touch screen compared with paper support was shown depending on activities. Overall, our data do not confirm the hypothesis that touch screen presentation improves activity completion and behavioural performance for each individual with ASD. Data discourage an indiscriminate use of these devices and suggest analysing with more attention the core ingredients that should shape digital devices when used for people on ASD.

Effectiveness of a Standardized Equine-Assisted Therapy Program for Children with Autism Spectrum Disorder

In this study the effectiveness of an equine-assisted therapy (EAT) in improving adaptive and executive functioning in children with autism spectrum disorder (ASD) was examined (children attending EAT, n = 15, control group n = 13; inclusion criteria: IQ > 70). Therapeutic sessions consisted in structured activities involving horses and included both work on the ground and riding. Results indicate an improvement in social functioning in the group attending EAT (compared to the control group) and a milder effect on motor abilities. Improved executive functioning was also observed (i.e. reduced planning time in a problem-solving task) at the end of the EAT program. Our findings provide further support for the use of animal-assisted intervention programs as complementary intervention strategies for children with ASD.

Reduced miR-659-3p Levels Correlate with Progranulin Increase in Hypoxic Conditions: Implications for Frontotemporal Dementia

Progranulin (PGRN) is a secreted protein expressed ubiquitously throughout the body, including the brain, where it localizes in neurons and is activated microglia. Loss-of-function mutations in the GRN gene are an important cause of familial frontotemporal lobar degeneration (FTLD). PGRN has a neurotrophic and anti-inflammatory activity, and it is neuroprotective in several injury conditions, such as oxygen or glucose deprivation, oxidative injury, and hypoxic stress. Indeed, we have previously demonstrated that hypoxia induces the up-regulation of GRN transcripts. Several studies have shown microRNAs (miRNAs) involvement in hypoxia. Moreover, in FTLD patients with a genetic variant of GRN (rs5848), the reinforcement of miR-659-3p binding site has been suggested to be a risk factor. Here, we report that miR-659-3p interacts directly with GRN 3′UTR as shown by luciferase assay in HeLa cells and ELISA and Western Blot analysis in HeLa and Kelly cells. Moreover, we demonstrate the physical binding between GRN mRNA and miR-659-3p employing a miRNA capture-affinity technology in SK-N-BE and Kelly cells. In order to study miRNAs involvement in hypoxia-mediated up-regulation of GRN, we evaluated miR-659-3p levels in SK-N-BE cells after 24 h of hypoxic treatment, finding them inversely correlated to GRN transcripts. Furthermore, we analyzed an animal model of asphyxia, finding that GRN mRNA levels increased at post-natal day (pnd) 1 and pnd 4 in rat cortices subjected to asphyxia in comparison to control rats and miR-659-3p decreased at pnd 4 just when GRN reached the highest levels. Our results demonstrate the interaction between miR-659-3p and GRN transcript and the involvement of miR-659-3p in GRN up-regulation mediated by hypoxic/ischemic insults.

Effects of maternal chlorpyrifos diet on social investigation and brain neuroendocrine markers in the offspring - a mouse study

BACKGROUND

Chlorpyrifos (CPF) is one of the most widely used organophosphate pesticides worldwide. Epidemiological studies on pregnant women and their children suggest a link between in utero CPF exposure and delay in psychomotor and cognitive maturation. A large number of studies in animal models have shown adverse effects of CPF on developing brain and more recently on endocrine targets. Our aim was to determine if developmental exposure to CPF affects social responsiveness and associated molecular neuroendocrine markers at adulthood.

METHOD

Pregnant CD1 outbred mice were fed from gestational day 15 to lactation day 14 with either a CPF-added (equivalent to 6 mg/kg/bw/day during pregnancy) or a standard diet. We then assessed in the offspring the long-term effects of CPF exposure on locomotion, social recognition performances and gene expression levels of selected neurondocrine markers in amygdala and hypothalamus.

RESULTS

No sign of CPF systemic toxicity was detected. CPF induced behavioral alterations in adult offspring of both sexes: CPF-exposed males displayed enhanced investigative response to unfamiliar social stimuli, whereas CPF-exposed females showed a delayed onset of social investigation and lack of reaction to social novelty. In parallel, molecular effects of CPF were sex dimorphic: in males CPF increased expression of estrogen receptor beta in hypothalamus and decreased oxytocin expression in amygdala; CPF increased vasopressin 1a receptor expression in amygdala in both sexes.

CONCLUSIONS

These data indicate that developmental CPF affects mouse social behavior and interferes with development of sex-dimorphic neuroendocrine pathways with potential disruptive effects on neuroendocrine axes homeostasis. The route of exposure selected in our study corresponds to relevant human exposure scenarios, our data thus supports the view that neuroendocrine effects, especially in susceptible time windows, should deserve more attention in risk assessment of OP insecticides.

Endocrine disrupters: a review of some sources, effects, and mechanisms of actions on behaviour and neuroendocrine systems

Some environmental contaminants interact with hormones and may exert adverse consequences as a result of their actions as endocrine disrupting chemicals (EDCs). Exposure in people is typically a result of contamination of the food chain, inhalation of contaminated house dust or occupational exposure. EDCs include pesticides and herbicides (such as dichlorodiphenyl trichloroethane or its metabolites), methoxychlor, biocides, heat stabilisers and chemical catalysts (such as tributyltin), plastic contaminants (e.g. bisphenol A), pharmaceuticals (i.e. diethylstilbestrol; 17α-ethinylestradiol) or dietary components (such as phytoestrogens). The goal of this review is to address the sources, effects and actions of EDCs, with an emphasis on topics discussed at the International Congress on Steroids and the Nervous System. EDCs may alter reproductively-relevant or nonreproductive, sexually-dimorphic behaviours. In addition, EDCs may have significant effects on neurodevelopmental processes, influencing the morphology of sexually-dimorphic cerebral circuits. Exposure to EDCs is more dangerous if it occurs during specific 'critical periods' of life, such as intrauterine, perinatal, juvenile or puberty periods, when organisms are more sensitive to hormonal disruption, compared to other periods. However, exposure to EDCs in adulthood can also alter physiology. Several EDCs are xenoestrogens, which can alter serum lipid concentrations or metabolism enzymes that are necessary for converting cholesterol to steroid hormones. This can ultimately alter the production of oestradiol and/or other steroids. Finally, many EDCs may have actions via (or independent of) classic actions at cognate steroid receptors. EDCs may have effects through numerous other substrates, such as the aryl hydrocarbon receptor, the peroxisome proliferator-activated receptor and the retinoid X receptor, signal transduction pathways, calcium influx and/or neurotransmitter receptors. Thus, EDCs, from varied sources, may have organisational effects during development and/or activational effects in adulthood that influence sexually-dimorphic, reproductively-relevant processes or other functions, by mimicking, antagonising or altering steroidal actions.

Prenatal chlorpyrifos exposure alters motor behavior and ultrasonic vocalization in CD-1 mouse pups

BACKGROUND

Chlorpyrifos (CPF) is a non-persistent organophosphate (OP) largely used as pesticide. Studies from animal models indicate that CPF is a developmental neurotoxicant able to target immature central nervous system at dose levels well below the threshold of systemic toxicity. So far, few data are available on the potential short- and long-term adverse effects in children deriving from low-level exposures during prenatal life and infancy.

METHODS

Late gestational exposure [gestational day (GD) 14-17] to CPF at the dose of 6 mg/kg was evaluated in CD-1 mice during early development, by assessment of somatic and sensorimotor maturation [reflex-battery on postnatal days (PNDs) 3, 6, 9, 12 and 15] and ultrasound emission after isolation from the mother and siblings (PNDs 4, 7 and 10). Pups' motor skills were assessed in a spontaneous activity test on PND 12. Maternal behavior of lactating dams in the home cage and in response to presentation of a pup previously removed from the nest was scored on PND 4, to verify potential alterations in maternal care directly induced by CPF administration.

RESULTS

As for the effects on the offspring, results indicated that on PND 10, CPF significantly decreased number and duration of ultrasonic calls while increasing latency to emit the first call after isolation. Prenatal CPF also reduced motor behavior on PND 12, while a tendency to hyporeflexia was observed in CPF pups by means of reflex-battery scoring. Dams administered during gestation with CPF showed baseline levels of maternal care comparable to those of controls, but higher levels of both pup-directed (licking) and explorative (wall rearing) responses.

CONCLUSION

Overall our results are consistent with previous epidemiological data on OP neurobehavioral toxicity, and also indicate ultrasonic vocalization as an early marker of CPF exposure during development in rodent studies, with potential translational value to human infants.

Long-term effects on hypothalamic neuropeptides after developmental exposure to chlorpyrifos in mice

BACKGROUND

Increasing evidence from animal and human studies indicates that chlorpyrifos (CPF), similar to other organophosphorus insecticides still widely used, is a developmental neurotoxicant. Developmental exposure to CPF in rodents induces sex-dimorphic behavioral changes at adulthood, including social and agonistic responses, which suggests that CPF may interfere with maturation of neuroendocrine mechanisms.

OBJECTIVES

We assessed the hypothesis that CPF affects the levels of neurohypophyseal hormones acting as modulators of social behavior in mammals, such as oxytocin (OT), arginine vasopressin (AVP), and prolactin (PRL).

METHODS

Pregnant female mice were orally administered with either vehicle (peanut oil) or 3 or 6 mg/kg CPF on gestational day (GD) 15 to GD18, and offspring were treated subcutaneously with either vehicle or 1 or 3 mg/kg CPF on postnatal days (PNDs) 11 to PND14. Dose levels were chosen to avoid systemic toxicity and inhibition of brain acetylcholinesterase. Offspring were sacrificed at 5 months of age, and expression of OT, AVP, and PRL was analyzed in the hypothalamus by Western blot or enzyme-linked immunosorbent assay (ELISA) analysis.

RESULTS

Both male and female mice showed dose-related enhancement of OT expression, with males presenting the more intense effect. AVP expression was significantly reduced in male mice at the higher prenatal and postnatal dose. We observed no significant effect on PRL expression in either sex. Overall, outcomes were mainly attributable to fetal exposure, whereas postnatal doses appeared to potentiate the prenatal effects.

CONCLUSIONS

Our data indicate that developmental exposure to CPF may permanently interfere with specific key signaling proteins of the hypothalamic peptidergic system, with time-, dose-, and sex-related effects still evident at adulthood.

Behavioral and electrophysiological effects of the adenosine A2A receptor antagonist SCH 58261 in R6/2 Huntington's disease mice

The effect of chronic treatment with the selective adenosine A2A receptor antagonist SCH 58261 on the behavioral and electrophysiological alterations typical of R6/2 mice (a transgenic mouse model of Huntington's disease, HD), has been studied. Starting from 5 weeks of age, R6/2 and wild type (WT) mice were treated daily with SCH 58261 (0.01 mg/kg i.p.) for 7 days. In the following weeks, the ability of mice to perform in the rotarod, plus maze and open field tests were evaluated. In addition, with electrophysiological experiments in corticostriatal slices we tested whether the well-known increased NMDA vulnerability of R6/2 mice was prevented by SCH 58261 treatment. We found that chronic treatment with SCH 58262: i) fully prevented the alterations in emotional/anxious responses displayed by R6/2 mice; ii) did not prevent the impairment in motor coordination; iii) abolished the increase in NMDA-induced toxicity observed in the striatum of HD mice. On balance, targeting A2A receptors seems to have some beneficial effects in HD even though, given the complexity of A2A receptor pharmacology and HD pathogenesis, further studies are necessary to clarify whether A2A receptor antagonists have therapeutic potential in HD.

Neonatal basal forebrain cholinergic hypofunction affects ultrasonic vocalizations and fear conditioning responses in preweaning rats

The present study investigated the effects of intracebroventricular injections of 192 IgG-saporin in 7-day-old rats on (i) ultrasound vocalizations (USVs) on postnatal day (pnd) 13 following isolation and reunion with the mother and (ii) fear conditioning on pnd 18-19 recording both freezing and other behavioural responses as well as USVs. On pnd 13 lesioned and control pups showed comparable USV baseline values; a brief reunion with the mother induced a significant increase in USVs in all rats (maternal potentiation). On pnd 18, during the fear conditioning training, 192 IgG-saporin rats emitted a lower number of USVs. On pnd 19 all rats showed a stronger conditioned response (with full inhibition of locomotion) to auditory than to contextual cues. Surprisingly, lesioned rats showed a stronger fear-conditioned response to contextual cues than controls. These results suggest that early selective removal of the cholinergic basal forebrain paradoxically enhances hippocampally dependent fear-conditioned responses on pnd 19.

Acute perinatal asphyxia at birth has long-term effects on behavioural arousal and maternal behaviour in lactating rats

This study analysed the long-term consequences of an asphyctic event at birth on maternal behaviour and emotionality in rats. Pregnant Wistar rats were delivered by Caesarean section and the pups, still in the uterus horns, were placed into a water bath at 37 degrees C for periods of 0 (Caesarean delivery, CD) or 20 min (asphyxia, CD+20). Control subjects were born by vaginal delivery (VD). Subsequently, pups were given to surrogate mothers, weaned at 21 days, and mated at adulthood. After giving birth, differences in maternal competence and behavioural arousal were assessed observing: (i) maternal behaviour after reunion with the pups following a 3h separation, on postpartum day (PPD) 4; (ii) behaviour in an elevated plus-maze test, on postpartum day 7; and (iii) performance in a fear conditioning test, in which subjects learned to associate a conditional stimulus with an aversive unconditioned stimulus (postpartum days 7-8). Results indicate that subjects in the CD+20 group showed a deficit in maternal care, taking a longer time to retrieve the whole litter and often failing to retrieve all pups. Both CD and CD+20 groups showed higher behavioural activity in the plus-maze. In addition, when tested in the fear conditioning paradigm, the CD+20 group showed a lower latency to perform freezing behaviour in the auditory cue trial. The changes in behavioural arousal described suggest that the dopaminergic system may be a potential neurochemical target for an early hypoxic insult and indicate maternal behaviour as a useful endpoint to study the effects of early birth insult on brain function.

Efficient testing strategies for evaluation of xenobiotics with neuroendocrine activity

Maturation of neuroendocrine regulations is an extremely complex process made up of several stages, that can be permanently affected by any exogenous substances able to interfere with the hormonal signalling at various levels. The Endocrine Disrupting Chemicals (EDCs) are a heterogeneous group of xenobiotics with potential endocrine activities which have been identified as priority risk factors in toxicological research. The present review is aimed at suggesting a number of endocrine and behavioural endpoints to be used in experimental studies to: (i) characterize more thoroughly the functional effects of developmental exposure to agents known to act as endocrine disruptors and (ii) unmask possible interferences with the maturation of the hypothalamus-hypophysis-gonad/thyroid (HHG/Th) axis by different class of xenobiotics not considered as EDCs. A combined testing strategy, considering both markers of endocrine/hormonal maturation and behavioural endpoints under hormonal control in laboratory rodents, may evidence even subtle perturbations of the neuroendocrine homeostasis, that often go undetected.

Developmental neurotoxicity of organophosphorous pesticides: fetal and neonatal exposure to chlorpyrifos alters sex-specific behaviors at adulthood in mice

Developmental exposure to the organophosphorous insecticide chlorpyrifos (CPF) induces long-term effects on brain and behavior in laboratory rodents. We evaluated in adult mice the behavioral effects of either fetal and/or neonatal CPF exposure at doses not inhibiting fetal and neonatal brain cholinesterase. CPF (3 or 6 mg/kg) was given by oral treatment to pregnant females on gestational days 15-18 and offspring were treated sc (1 or 3 mg/kg) on postnatal days (PNDs) 11-14. Serum and brain acetylcholinesterase (AChE) activity was evaluated at birth and 24 h from termination of postnatal treatments. On PND 70, male mice were assessed for spontaneous motor activity in an open-field test and in a socioagonistic encounter with an unfamiliar conspecific. Virgin females underwent a maternal induction test following presentation of foster pups. Both sexes were subjected to a plus-maze test to evaluate exploration and anxiety levels. Gestational and postnatal CPF exposure (higher doses) affected motor activity in the open field and enhanced synergically agonistic behavior. Postnatal CPF exposure increased maternal responsiveness toward pups in females. Mice of both sexes exposed to postnatal CPF showed reduced anxiety response in the plus-maze, an effect greater in females. Altogether, developmental exposure to CPF at doses that do not cause brain AChE inhibition induces long-term alterations in sex-specific behavior patterns of the mouse species. Late neonatal exposure on PNDs 11-14 was the most effective in causing behavioral changes. These findings support the hypothesis that developmental CPF may represent a risk factor for increased vulnerability to neurodevelopmental disorders in humans.

A social recognition test for female mice reveals behavioral effects of developmental chlorpyrifos exposure

CD-1 mice were exposed to the organophosphate pesticide chlorpyrifos (CPF) both prenatally (gestational days 15-18; doses 0, 3 or 6 mg/kg) and postnatally (postnatal days 11-14, doses 0, 1 or 3 mg/kg). When four-month-olds, females underwent a social recognition test in which ultrasound vocalizations (USVs) and social investigation behavior emitted by a resident female in the presence of a female partner were measured during two subsequent 3 min sessions (interval between the two sessions 45 min). Throughout the social recognition test a marked increase in USVs was found in females prenatally treated with the highest CPF dose; USV increase was also paralleled by a selective increase in frequency and not in duration of social investigation. These results confirm that developmental exposure to CPF induces long-lasting alterations in the social behavior repertoire of the mouse, thus extending our previous observations on the effects of postnatal CPF on male agonistic behavior to the female sex. They also suggest that social recognition can be easily and rapidly assessed in the female mouse making it possible to evaluate, primarily by means of USV emission, even subtle alteration of social behavioral patterns dissociated from cognitive components of individual recognition.

C-section birth per se or followed by acute global asphyxia altered emotional behaviour in neonate and adult rats

Birth complications such as perinatal asphyxia are considered risk factors for later neurobehavioural disorders. Behavioural analysis of animal models may help to clarify the contribution of particular patterns of early hypoxia and their combination to psychiatric morbidity. Wistar rats underwent caesarean section (c-section) alone or c-section followed by asphyxia, the latter induced by placing pups still in uterus horns into a water bath at 37 degrees C for 20 min. Vaginally delivered pups were used as controls. Frequency of ultrasound emissions was analysed following isolation at a lower temperature than that of the home nest (23+/-0.5 degrees C) and reunion with their mother (3 min) on postnatal day (PND) 13 (maternal potentiation test). A sex-dependent effect of hypoxia was observed, with higher production of ultrasounds in hypoxic males. Caesarean-delivered pups produced significantly more ultrasounds than those vaginally delivered. At adolescence (PND 35) rats underwent a 25 min social interaction test with a conspecific of the same sex and age. Significant alterations in investigative behaviour (inclusive of: nose, anogenital, body sniffing, and following) were evident in caesarean-delivered rats of both sexes, but not in rats experiencing perinatal asphyxia. At adulthood, auditory, and context conditioned responses, analysed in a fear conditioning test, were not markedly affected either by c-section or c-section plus hypoxia. However, hypoxic rats emitted significantly more 22 kHz ultrasounds than c-section or vaginally delivered rats during the training session. In conclusion, differential effects appear to be brought about by c-section and by hypoxia mainly related to emotional/anxious responses.

Neurobehavioral effects of prenatal exposure to AZT: a preliminary investigation with the D1 receptor agonist SKF 38393 in mice

Zidovudine (AZT) is the main therapeutic agent against HIV vertical transmission and is routinely administered to seropositive pregnant women and their newborns. Toxicity after chronic administration as well as citogenetic effects following developmental AZT exposure has been reported. Furthermore, recent animal data indicate alterations of several behavioral endpoints during the entire lifespan of mice and rats after developmental AZT exposure. In this study, we investigated specific central nervous system (CNS) effects of AZT administration during pregnancy on the offspring. CD-1 mouse females were administered twice daily from day 10 of pregnancy until delivery with either AZT (160 mg/kg) or saline (0.9% NaCl). On PND, 60 male offsprings received an intraperitoneal injection of the D1 receptor agonist 2,3,4,5-tetra-hydro-7,8-diol-1-phenyl-(1H)-3-benzazepine (SKF 38393) (0, 3, and 10 mg/kg), and spontaneous behavior was assessed in an automated activity chamber for 40 min. At variance from what observed in control mice that displayed excessive grooming when administered the higher dose of the D1 agonist, SKF 38393 failed to increase duration of grooming in AZT-treated mice. These data suggest that the D1 receptorial dopaminergic subsystem might be hyporesponsive in mice prenatally exposed to AZT.

Behavioral responses of 129/Sv, C57BL/6J and DBA/2J mice to a non-predator aversive olfactory stimulus

We examined the behavior of three inbred mouse strains (129/SvPasIco, C57BL/6J, and DBA/2J) exposed to an object soaked with the chemical component of the aversive scent (toluquinone odor) emitted by a myriapod species (Ommatoiulus sabulosus) in the presence of a predator. Subjects were exposed to the odor for three consecutive days. Behavioral responses to the toluquinone odor were characterized both by an approach phase of risk assessment and by a repeated series of approach-avoid episodes. Results indicate that toluquinone exposure reduced completely, and in a strain independent fashion, selected behaviors such as crouching, catching and eating object. Other responses were strain-dependent: the DBA (DBA/2J) strain displayed defensive burying at high levels, C57 (C57BL/6J) mice performed high levels of withdrawal while the 129/Sv (129/SvPasIco) strain showed also high levels of stretch attend posture. Compared to other tasks, this test is ethological, simple, cheap and is not affected by strain differences in appetitive-sensory responses, as shown by some strain-independent responses. These features make this task as a good complement to any exploration-anxiety test battery.

Acute global anoxia during C-section birth affects dopamine-mediated behavioural responses and reactivity to stress

Perinatal asphyxia may induce major neurological deficits shortly after birth as well as neurological/behavioural disorders later in development. We used a rat model of global perinatal asphyxia to model acute intrauterine asphyxia around the time of birth. Caesarean section was performed in rats and their pups, still in uterus horns, were placed into a water bath at 37 degrees C for periods of 0, 10 or 20 min. Pups were then given to surrogate mothers, and examined for long-term behavioural effects of the perinatal asphyctic insult. Behavioural assessment included analysis of novelty seeking behaviour at adolescence, while spatial discrimination abilities, response to both an acute and a chronic stress, and the effects of the full D1 receptor agonist SKF 82958 on open field behaviour were assessed at adulthood. Overall, no marked abnormalities were found in the novelty seeking test, in the ability to discriminate spatial changes in the test environment and in physiological response to stress. However, adult rats subjected to severe perinatal asphyxia (20 min) showed lower activity level and lower stereotyped behaviour after the administration of SKF 82958 in an open field test. These results support the observations from human and animal studies that perinatal insult can produce long-term dysfunction of dopaminergic neurotransmission, and points to the need of more thorough examination of the potential effects of perinatal asphyxia on hypothalamic-pituitary-adrenal (HPA) axis. Altogether, the present findings suggest that the present 20 min perinatal asphyxia model might serve for the study of neurodevelopmental disorders associated with perinatal insults.

Long-term effects of acute perinatal asphyxia on rat maternal behavior

In this study we used a rat model of graded perinatal asphyxia to study the long-term consequences of this manipulation on rat maternal behavior at adulthood. Rats were delivered by cesarean (C) section and the pups, still in the uterus horns, were placed into a water bath at 37 degrees C for periods of 0 (controls) or 20 min (asphyxia). Subsequently, female pups were given to surrogate mothers, weaned at 21 days postnatally and then left undisturbed until adulthood, when they were mated. Once they gave birth, on postnatal days (Pnds) 1, 3, 5, 7, 9, 11 and 13 they were observed in the home cage five times per day to assess their maternal behavior in an undisturbed condition. In addition, maternal behavior was observed for 30 min in a novel cage on Pnds 4 and 8. Perinatal asphyxia affected maternal behavior in the home cage, hypoxic females being more often found outside the nest area and performing more often behaviors such as self-grooming. Principal component analysis confirmed a more 'active' behavioral profile for hypoxic females. Hypoxic mothers were characterized by a longer latency to perform on-nest behavior and by a reduced frequency of pup retrieval and licking in the novel cage. No significant differences in corticosterone secretion in response to an acute stressor were found in dams belonging to the different treatments or in the body weights of the offspring. These results are suggestive of an arousal deficit due to perinatal hypoxia and point to the dopaminergic system as a potential neurochemical target for an early hypoxic insult.

Prolonged perinatal AZT administration and early maternal separation: effects on social and emotional behaviour of periadolescent mice

Zidovudine (AZT) is an effective treatment in preventing perinatal transmission of HIV-1; however, a continuous re-evaluation of the risk-benefit ratio of human exposure to this drug is suggested by both clinical and animal studies. The objective of this study was to assess the medium and long-term effects of pre-postnatal AZT treatment on mouse social and emotional behaviour and the possible interactions between AZT exposure and disruptions in the mother-infant relationship. Pregnant CD-1 mice were administered per os with AZT (160 mg/kg) from pregnancy day 10, throughout delivery, to lactation day 10. In half of the litters, the offspring was separated from the mother for 3 h from postnatal days 2 (PND2) to PND14. On PND35, a 30-min social interaction test was performed and corticosterone levels were measured at the end of the session. On PND80, long-term effects of AZT on emotionality were assess by means of an elevated plus-maze. Results indicate that, on PND35, previous AZT exposure affected social behaviour of the experimental subjects, reducing aggressive interactions in males, while decreasing investigative behaviours in females. At adulthood, AZT inhibited exploratory behaviour in the plus-maze while increasing the frequency of risk-assessment postures in male mice. As for maternal deprivation, this early manipulation exerted a pro-aggressive effect in adolescent male mice, deprived subjects being overall characterised by higher activity levels and a deficit in habituation, an effect also observed in the plus-maze. A significant interaction between AZT and maternal deprivation was found for affiliative behaviours. As for corticosterone levels, no AZT effect was found, while maternal deprivation tended to reduce elevations of this hormone in response to stressful stimuli. Overall results from this study indicate that both AZT exposure and maternal deprivation induced gender-dependent changes in social and emotional behaviour both during adolescence and at adulthood.

Animal models of anti-HIV drugs exposure during pregnancy: effects on neurobehavioral development

In the last 10 years, zidovudine (AZT) has become the main prophylactic therapy against vertical HIV-1 transmission. AIDS Clinical Trials Group (ACTG) 076 have demonstrated that the administration of AZT to HIV-infected women during their third trimester of pregnancy, trough labor and given orally to babies for 6 weeks, reduced by two-thirds the rate of vertical infection. Although the rapid diffusion of this regimen into clinical practice together with the implementation of HIV counseling and testing practices have dramatically reduced the vertical transmission rate in the US and Western Europe, there is a growing concern on the adverse effects of antiretroviral therapy on the fetus and the newborn. In fact, even though shorter regimen therapies that are less complex and expensive to implement in poor countries have been demonstrated as effective as ACTG 076 regimen, the distribution of the risk of vertical transmission in the developing countries is still very high. Consequently, a large number of unborns will be a candidate to developmental exposure to antiretroviral agents. To date, data on the transplacental mutagenicity, carcinogenicity and mitochondrial dysfunction induced by developmental exposure to AZT have been reported in several animal models. Furthermore, one study reported severe yet few human cases of cardiomyopathy and neurological disease likely associated with mitochondrial dysfunction in uninfected infants of seropositive mothers perinatally exposed to AZT. For all of these reasons, many investigations have been focusing on the assessment of the potential adverse effects of nucleoside reverse transcriptase (RT) inhibitors (NRTI) administration during development. A survey of the main results derived from clinical and animal studies is reported here, focusing on those neurobehavioral studies that have been looking for specific and/or aspecific changes in the nervous system induced by NRTI exposure in utero.

Prenatal AZT or 3TC and mouse development of locomotor activity and hot-plate responding upon administration of the GABA(A) receptor agonist muscimol

RATIONALE

Zidovudine (AZT) and lamivudine (3TC) are nucleoside analogues administered prenatally in clinical practice, separately or in combination, as antiretroviral drugs to prevent HIV mother-to-child transmission by inhibiting viral reverse transcriptase. In animal studies pre- and/or perinatal exposure to AZT and 3TC induce age- and sex-dependent neurobehavioural alterations in the offspring.

OBJECTIVE

Investigation of short- and medium-term effects of in utero exposure to AZT or 3TC on development of the GABAergic system.

METHODS

Pregnant CD-1 mice were given orally twice daily AZT (160 mg/kg), 3TC (500 mg/kg) or vehicle solution (NaCl 0.9%) from pregnancy day 10 to delivery. Offspring locomotion and nociceptive sensitivity were examined on postnatal day (pnd) 8, 14, and 28 after administration of two doses of GABAergic agonist muscimol (pnd 8 and 14: 0.05 and 0.2 mg/kg; pnd 28: 0.2 and 1.0 mg/kg). A 30-min locomotor activity test and a 60 s hot-plate test (50+/-1 degrees C) were used.

RESULTS

AZT and 3TC treated mice showed a mild increase of locomotor activity after administration of the high dose muscimol on pnd 8. On pnd 14 the low muscimol dose enhanced locomotor activity in vehicle and 3TC, but not in AZT pups, whereas no prenatal treatment effect was evident on pnd 28. AZT increased nociceptive sensitivity at all ages considered.

CONCLUSIONS

Prenatal AZT effects on locomotor activity appear clearly detectable after GABAergic challenge and seem to be transient. AZT effects on pain sensitivity did not appear to be dependent on GABA regulated nociceptive mechanisms. Prenatal 3TC exposure had rather limited effects on locomotor activity development, and no effect on nociception.

Prenatal exposure to anti-HIV drugs: neurobehavioral effects of zidovudine (AZT) + lamivudine (3TC) treatment in mice

BACKGROUND

The new antiretroviral treatments that combine the zidovudine (AZT) regimen with lamivudine (3TC) appear as a cost-effective alternative to the current AZT monotherapy to prevent mother-to-fetus transmission of the HIV-1 virus. Recent evidence in uninfected children raised concern about the long-term effects of perinatal exposure to AZT and 3TC, especially when used in combination. Animal studies indicated behavioral changes in offspring exposed perinatally to both AZT and 3TC, whereas no animal data are available on the effects of the perinatal exposure to the AZT + 3TC combination on neurodevelopment.

METHODS

Pregnant CD-1 mice received p.o. AZT + 3TC (160 and 500 mg/kg, respectively) or vehicle solution (NaCl 0.9%) twice daily from gestational day 10 to delivery. Maternal reproductive endpoints such as pregnancy length, abortion, litter size, sex ratio, and offspring viability were assessed. Pups were scored for different somatic and behavioral endpoints, including sensorimotor development, homing performance on postnatal day (PND) 10, passive-avoidance testing (PND 22-23), locomotor activity (PND 23), and social interaction (PND 35).

RESULTS

While no effects were observed on maternal reproductive endpoints, treated pups showed a long-lasting reduction of body weight and a slightly delayed maturation of placing and grasping reflexes and pole grasping. No effects on passive-avoidance or locomotor activity were found. AZT + 3TC-treated mice showed selective alterations in the social interaction test; the treated female offspring also displayed a significant reduction of affiliative interactions.

CONCLUSIONS

The combination of AZT and 3TC (1) induced small, but more marked, effects on somatic and sensorimotor development than either of these drugs administered separately; and (2) affected juvenile social behavior.

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.

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.

Prenatal exposure to anti-HIV drugs. long-term neurobehavioral effects of lamivudine (3TC) in CD-1 mice

The present study was aimed at investigating the long-term effects of prenatal exposure to lamivudine (3TC), an antiretroviral drug used in clinical practice alone or in combination with zidovudine (AZT) to prevent mother-to-child transmission of the HIV virus. Pregnant CD-1 mice were given per os twice daily either 3TC at different doses (125, 250, or 500 mg/kg) or vehicle solution (NaCl 0. 9%) from pregnancy day 10 to delivery. Offspring behavior was examined on postnatal day 35 in a 20-min social interaction test. At adulthood different behavioral endpoints were analyzed, including locomotor activity and exploration in an open field following administration of the muscarinic antagonist scopolamine (2 mg/kg), spatial learning in either radial arm or Morris water maze, virgin female behavior in a maternal induction test, and pain sensitivity in a hot-plate test (52 +/- 0.1 degrees C). Our findings confirm the low neurotoxicity of 3TC in comparison to AZT. However some significant behavioral alterations were found, namely (1) a decrease in immobility in the open field test, (2) an increase in the responsiveness to scopolamine shown by the 500-mg/kg 3TC mice (sniffing behavior) in the open field, and (3) a longer escape latency in the first day of the reversal phase in the Morris task (particularly marked in the 250-mg/kg treatment group). No significant changes in either pain sensitivity, social/affiliative, or maternal behavior were found, although a higher occurrence of aggressive behavior toward foster pups was noted in both 125- and 500-mg/kg 3TC females.

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.

Neurobehavioral effects of prenatal lamivudine (3TC) exposure in preweaning mice

The present study provides a characterization of the behavioral changes induced in preweaning mice by prenatal exposure to lamivudine (3TC), an antiviral drug recently entered in the clinical practice to treat HIV patients. Pregnant CD1 mice were given per os bidaily either 3TC at different doses (125, 250, or 500 mg/kg) or vehicle solution (saline 0.9%) from pregnancy day 10 to delivery. Data on reproductive performance, such as gestation length, litter size, and offspring viability, were collected. Offspring were then examined for a series of different somatic and behavioral end points, including sensorimotor development, ontogenetic pattern of ultrasonic vocalization, passive avoidance learning, and locomotor activity. In the absence of gross changes in somatic and sensorimotor development, a slight change in ultrasound emission was found on postnatal day (PND) 3, with 125 and 500 mg/kg 3TC-treated offspring emitting a lower number of ultrasounds. Learning and retention performances of a passive-avoidance task on PND 20-21 were unaffected by 3TC treatment, while decreased habituation in an automated locomotor activity test was evident in male offspring exposed to 250 and 500 mg/kg 3TC.

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.

Effects of prenatal AZT on mouse neurobehavioral development and passive avoidance learning

Recent evidence has shown that perinatal administration of zidovudine (AZT) to HIV-infected mothers reduces the risk of maternal-infant transmission of the virus. Treatment of pregnant seropositive women with AZT is becoming a common medical practice, despite the paucity of information about the potential neurotoxic/behavioral-teratogenic effects of AZT on the developing organism. The aim of the present study is to evaluate in mice the short-, medium-, and long-term effects of prenatal exposure to AZT on neurobehavioral development. Pregnant mice were given 0.2, 0.4, and 2.0 mg/ml AZT in drinking water from day 10 of gestation to delivery. Offspring's viability was severely affected in the 2.0 mg/ml AZT group. Thus, behavioral analysis was carried out in offspring of 0.2 and 0.4 mg/ml AZT-treated females only. Some limited but significant alterations were found, such as stunted body weight, delayed appearance of the pole-grasping reflex, and a slight impairment in the acquisition phase of a passive avoidance response. Moreover, sexual differences in some items of the social behavior repertoire appeared to be affected by AZT treatment.