B6 ja 129Sv hiireliinide käitumuslik ja geneetiline võrdlus, mis keskendub ärevuskäitumisele ja Lsamp geeni ekspressioonile

Väitekirja elektrooniline versioon ei sisalda publikatsioone.Kaasaegne neuroteadus vajab hiiri nii baasteaduses haiguste ja häirete mudeldamiseks kui ravimiarenduse valdkonnas ohutuse testimisel, enne kui ravimikandidaati tohib hakata inimeste peal katsetama. Tänapäevased näriliste mudelid püüdlevad etoloogilisema lähenemise poole. Loomade elutingimused ja ka katsed peavad toimuma võimalikult loomuomases keskkonnas. Surve selliseks lähenemiseks kasvab nii teadlaste kogukonnast, kes tahavad, et nende tulemused oleksid võimalikult valiidsed ja kõrge translatsioonilise väärtusega, kui ka seadusloome tasandilt (direktiiv 2010/63/EU), mis tuleb vastu heaoluühiskonna eeldustele loomade heaolu kohta. See, kuidas närilisi laborites kasvatatakse ja milliseid käitumiskatseid nendega tehakse, mõjutab katsetest saadud tulemusi. Käesolev doktoritöö hindab erinevates keskkonnatingimustes, see tähendab individuaalselt, tavapuuris või rikastatud keskkonnas üles kasvamise mõju klassikalistele hiireliinidele B6 ja 129Sv. Lisaks keskendub töö eelmainitud taustaliinidesse loodud Lsamp-puudulikkusega hiire iseloomustamisele. B6 hiired kasutavad varasemalt teadaolevalt keskkonnas toime tulemiseks ja kohanemiseks aktiivset toimetulekustrateegiat; samades tingimustes käituvad 129 liini hiired alalhoidlikult ja passiivselt. Tuvastasime uuringutega, et rikastatud keskkonnas elamine mõjub aktiivsetele B6 loomadele paremini kui ärevatele 129Sv liini hiirtele. Farmakoloogilised ja käitumiskatsete andmed viitavad, et 129Sv hiirte monoamiinsüsteem on rikastatud keskkonnas üle stimuleeritud, mis tingib ebaadekvaatse kohanemisreaktsiooni. Lsamp geen juhib närvisüsteemi kujunemisel neuronite ühenduste kujunemist. Mutatsioone selles geenis seostatakse ärevus- ja meeleoluhäiretega. Lsamp-puudulikkusega hiirtel, kellel see geen on välja lülitatud, esineb kõrvalekaldeid sotsiaalses käitumises ning uudses ja ärevas olukorras kohanemisel. Lsamp geenil on kaks promootorit: 1a ja 1b. Käesolevas töös näitasime esmakordselt nende erinevaid ekspressioonimustreid hiire ajus. 1b on transkriptsiooniliselt aktiivne sensoorsetes juhteteedes alates tuumadest ajutüves ja taalamuses kuni primaarsete sensoorsete aladeni ajukoores. 1a promootor ekspresseerub klassikalistes limbilistes struktuurides nagu hippokampus ja hüpotaalamus. Lsamp promootorite ekspressiooni tasemed hippokampuses käitumiskatsete järgselt viitavad, et koos Bdnfiga mängib lsamp olulist rolli aju plastilisuses ja kohanemiskäitumise reguleerimisel. Nii geneetiline taust kui kasvukeskkond mõjutavad Lsamp geeni ekspressiooni. Käesolevas töös näitame, et rikastatud keskkond suurendab Lsamp 1b transkripti ekspressiooni taset B6 hiirte hippokampuses; sama tendents ilmneb ka teise uuritud 129Sv liini juures ja mõlemal liinil 1a promootori puhul. Ka liinide vahel esineb märkimisväärseid erinevusi. Ärevate 129Sv loomade ajus on Lsamp 1a transkripti ekspressioon hippokampuses oluliselt kõrgem (hoolimata kasvukeskkonnast) kui B6 hiirtel. Samas Lsamp 1b transkript ekspresseerub kõrgemal tasemel B6 liini taalamuses ja ajukoores, mis võiks aidata seletada liinidevahelisi erinevusi füüsilises aktiivsuses, ruumilises mälus ja peenmotoorikas. Edasistes uuringutes tuleb vaadelda Lsampi ekspressiooni muutumist erinevates ajapunktides. Viimaste põlvkondade jooksul on läänemaailmas inimeste kasvukeskkond dramaatiliselt muutunud. Teisel viisil, kuid samaväärselt muutub ka laborinäriliste kasvukeskkond. Lisaks ebamugavustele, mis selliste muutustega kaasnevad, saab seda vaadelda kui võimalust avastamaks uusi fenotüüpe, mis varem ei saanud avalduda. Geenide ja keskkonna vahelised interaktsioonid väärivad süvitsi edasi uurimist nii transgeensetes loommudelites kui ühiskonnas laiemalt.Contemporary neuroscience needs mice in basic sciences to model diseases or disorders and in drug discovery for safety testing before a new drug can be entered into phase I studies on human subjects. Current rodent models aspire for ethological approach. Animal husbandry and experiments should take place in settings as close to natural as possible. Demand for such conditions is in rise in scientific community, who are interested in highly valid and translational results but compulsory by law (directive 2010/63/EU) which conforms to welfare society’s expectations about animal welfare. The results of animal experiments are influenced by the rearing conditions and the sort of experiments that are chosen. Present dissertation evaluates the impact of three rearing envrironments on common laboratory mouse strains B6 and 129Sv. The conditions are: individual housing, standard housing and enriched environment. Furthermore it will focus on describing Lsamp-deficient mice generated into abovementioned backgrounds. B6 mice are known to use active coping strategy while adapting to the environment; in a similar conditions 129Sv mice are passive and inhibited. With results presented in this dissertation we demonstrated that environmental enrichment is likely more beneficial for B6 male mice compared to more anxious 129Sv. Pharmacological and behavioural data indicates that the monoaminergic system of 129Sv mice is overstimulated in an enriched environment which leads to inadequate reaction. In a growing nervous system Lsamp gene guides the development of the connections between neurons. Mutations in the Lsamp gene are associated with anxiety and mood disorders. Lsamp-deficient mice have displayed abnormalities in social behaviour and in adaptations to the novel and anxiety provoking environment. Lsamp gene has two promoters: 1a and 1b. Current dissertation showed for the first time the differential expression pattern of those in the mouse brain. 1b is transcriptionally active in the in sensory pathways from nuclei in the brainstem and thalamus to the primary sensory cortex. 1a promoter is expressed in the classical limbic structures such as hippocampus and hypothalamus. The expression levels of Lsamp promoters in the hippocampus after behavioural experiments indicate that Lsamp along with a Bdnf plays an important role in the plasticity and in the regulation of adaptive behaviours. Genetic background and rearing environment influence the expression of Lsamp gene. In the current work we show that enriched environment elevates the expression of Lsamp 1b transcript in the hippocampi of B6 mice; similar tendency exists in other studied mouse line 129Sv and in both mouse lines for the 1a transcript. There are also remarkable differences between the strains. Anxious 129Sv animals (in all rearing environments) express more 1b transcript in their hippocampus than B6 mice. At the same time Lsamp 1b transcript is more highly expressed in the thalamus and cortex of B6 mice, which could help explain differences between the lines in locomotor activity, spatial memory and fine motor skills. In the future Lsamp expression has to be studied longitudinally. In western society the rearing environment for people has changed dramatically over the last few generations. Different but equally effective changes have happened in laboratory rodent environments. This does not have to be annoyance for the researcher, but can also be seen as an opportunity. The animals from the enriched environment can reveal phenotypes that could not have been discovered before. It is crucial to continue to investigate gene-environment interactions in trans-genetic animal models and in human population

Taasohvristamine riigi poolt pakutavates toetussüsteemides lähisuhtevägivalla ohvrite näitel

https://www.ester.ee/record=b5506101*es

Post-Socialist Dynamics of Value Patterns in Estonia

The article focuses on the dynamics of value patterns in Estonia over a period spanning late socialism to liberal market capitalism. The research data is derived from five population surveys ‘Work, family and leisure’ (WFL), in which value orientations were measured on the basis of Clyde Kluckhohn’s conception. The same instrument of life values was used in 1985 (just before the perestroika of Soviet socialist system), in 1993, 1998 and 2003 (during the transition period of post-socialism) and in 2008 (just before the economic crisis in capitalist society). The aim of the study is to differentiate value patterns and observe the trends of their change during this period. The results of hierarchical cluster analysis reveal a clear tendency of structural change: a dichotomy of value profiles on the ethno-linguistic basis in 1985 and 1993 was replaced by a dichotomy of value profiles on the basis of age in 2003 and 2008. The results of multidimensional analysis show a relative stability of the value structure and a change in the meaning of some life values (professional work, close friends). The results are discussed in the context of post-socialist societal transformation

Behavioural characterization of C57BL/6N and BALB/c female mice in social home cage – Effect of mixed housing in complex environment

Developing reliable mouse models for social behaviour is challenging. Different tests have been proposed, but most of them consist of rather artificial confrontations of unfamiliar mice in novel arenas or are relying on social stress induced by aggressive conspecifics. Natural social interaction in home cage in laboratory has not been investigated well. IntelliCage is a fully automated home-cage system, where activity of the group-housed mice can be monitored along with various cognitive tasks. Here we report the behavioural profile of C57BL/6N (86) and BALB/c (BALB) female mice in IntelliCage when separated by strain, followed by monitoring of activity and formation of 'home-base' after mixing two strains. For that purpose, 3 cages were connected. Significant differences between the strains were established in baseline behaviour in conventional tests and in IntelliCage. The B6 mice showed reduced anxiety-like behaviour in open field and light-dark box, slightly enhanced exploratory activity in IntelliCage during initial adaptation and clearly distinct circadian activity. Mixing of two strains resulted in reduction of body weight and anhedonia in B6 mice. In addition, the B6 mice showed clear preference to previous home-cage, and formed a new home-base faster than BALB mice. In contrast, BALB mice showed enhanced activity and moving between the cages without showing any preference to previous home-cage. It could be argued that social challenge caused changes in both strains and different coping styles are responsible for behavioural manifestations. Altogether, this approach could be useful in modelling and validating mouse models for disorders with disturbed social behaviour.Peer reviewe

Rat ultrasonic vocalizations and novelty-induced social and non-social investigation behavior in a seminatural environment

Although rats are known to emit ultrasonic vocalizations (USVs), it remains unclear whether these calls serve an auditory communication purpose. For USVs to be part of communication, the vocal signals will need to be a transfer of information between two or more conspecifics, and with the possibility to induce changes in the behavior of the recipient. Therefore, the aim of our study was to investigate the role of USVs in adult rats’ social and non-social investigation strategies when introduced into a large novel environment with unfamiliar conspecifics. We quantified a wide range of social and non-social behaviors in the seminatural environment, which could be affected by subtle signals, including USVs. We found that during the first hour in the seminatural environment the ability to vocalize did not affect how quickly adult rats met each other, their overall social investigation behavior, their passive social behavior nor their aggressive behavior. Furthermore, the non-social exploratory behaviors and behaviors reflecting anxiety/stress-like states were also unaffected. These results demonstrated that a disability to vocalize did not result in significant disadvantages (or changes) compared to intact conspecifics regarding social and non-social behaviors. This suggests that other (multi)sensory cues are more relevant in social interactions than USVs

Third-party prosocial behavior in adult female rats is impaired after perinatal fluoxetine exposure

SSRIs are commonly used to treat pregnant women with depression. However, SSRIs can cross the placenta and affect the development of the fetus. The effects of perinatal SSRI exposure, and especially the effects on social behavior, are still incompletely documented. This study first aims to investigate whether rats show prosocial behavior in the form of consolation behavior. Secondly, it aims to investigate whether perinatal SSRI exposure affects this prosocial behavior. At last, we investigate whether the behavior changed after the rats had been exposed to an additional white-noise stressor. Rat dams received 10 mg/kg/d fluoxetine (FLX) or vehicle (CTR) via oral gavage from gestational day 1 until postnatal day 21. At adulthood, the rat offspring were housed in four cohorts of 4 females and 4 males in a seminatural environment. As prosocial behaviors are more prominent after stressful situations, we investigated the behavioral response of rats immediately after natural aggressive encounters (fights). Additionally, we studied whether a stressful white-noise exposure would alter this response to the aggressive encounters. Our study indicates that CTR-female rats are able to show third party prosocial behavior in response to witnessing aggressive encounters between conspecifics in a seminatural environment. In addition, we showed that perinatal FLX exposure impairs the display of prosocial behavior in female rats. Moreover, we found no signs of prosocial behavior in CTR- and FLX-males after natural aggressive encounters. After white-noise exposure the effects in third party prosocial behavior of CTR-females ceased to exist. We conclude that female rats are able to show prosocial behavior, possibly in the form of consolation behavior. In addition, the negative effects of perinatal fluoxetine exposure on prosocial behavior could provide additional evidence that SSRI treatment during pregnancy could contribute to the risk for social impairments in the offspring

Perinatal fluoxetine treatment and dams' early life stress history alter affective behavior in rat offspring depending on serotonin transporter genotype and sex

Many women diagnosed with a major depression continue or initiate antidepressant treatment during pregnancy. Both maternal stress and selective serotonin inhibitor (SSRI) antidepressant treatment during pregnancy have been associated with changes in offspring behavior, including increased anxiety and depressive-like behavior. Our aim was to investigate the effects of the SSRI fluoxetine (FLX), with and without the presence of a maternal depression, on affective behavior in male and female rat offspring. As reduced serotonin transporter (SERT) availability has been associated with altered behavioral outcome, both offspring with normal (SERT+/+) and reduced (SERT+/-) SERT expression were included. For our animal model of maternal depression, SERT+/- dams exposed to early life stress were used. Perinatal FLX treatment and early life stress in dams (ELSD) had sex- and genotype-specific effects on affective behavior in the offspring. In female offspring, perinatal FLX exposure interacted with SERT genotype to increase anxiety and depressive-like behavior in SERT+/+, but not SERT+/-, females. In male offspring, ELSD reduced anxiety and interacted with SERT genotype to decrease depressive-like behavior in SERT+/-, but not SERT+/+, males. Altogether, SERT+/+ female offspring appear to be more sensitive than SERT+/- females to the effects of perinatal FLX exposure, while SERT+/- male offspring appear more sensitive than SERT+/+ males to the effects of ELSD on affective behavior. Our data suggest a role for offspring SERT genotype and sex in FLX and ELSD-induced effects on affective behavior, thereby contributing to our understanding of the effects of perinatal SSRI treatment on offspring behavior later in life

Effects of perinatal fluoxetine exposure on novelty-induced social and non-social investigation behaviors in a seminatural environment

Selective serotonin reuptake inhibitors (SSRIs) are increasingly prescribed as medication for various affective disorders during pregnancy. SSRIs cross the placenta and affect serotonergic neurotransmission in the fetus, but the neurobehavioral consequences for the offspring remain largely unclear. Recent rodent research has linked perinatal SSRI exposure to alterations in both social and non-social aspects of behavior. However, this research has mainly focused on behavior within simplified environments. The current study investigates the effects of perinatal SSRI exposure on social and non-social investigation behaviors of adult rat offspring upon introduction to a novel seminatural environment with unknown conspecifics. During the perinatal period (gestational day 1 until postnatal day 21), rat dams received daily treatment with either an SSRI (fluoxetine, 10 mg/kg) or vehicle. Adult male and female offspring were observed within the first hour after introduction to a seminatural environment. The results showed that perinatal fluoxetine exposure altered aspects of non-social investigation behaviors, while not altering social investigation behaviors. More specifically, both fluoxetine-exposed males and females spent more total time on locomotor activity than controls. Furthermore, fluoxetine-exposed females spent less time exploring objects and specific elements in the environment. The data suggest that perinatal exposure to SSRIs leads to a quicker, less detailed investigation strategy in novel environments and that the alteration is mostly pronounced in females. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00213-021-05984-8

Promoter-Specific Expression and Genomic Structure of IgLON Family Genes in Mouse

IgLON family is composed of five genes: Lsamp, Ntm, Opcml, Negr1, and Iglon5; encoding for five highly homologous neural adhesion proteins that regulate neurite outgrowth and synapse formation. In the current study we performed in silico analysis revealing that Ntm and Opcml display similar genomic structure as previously reported for Lsamp, characterized by two alternative promotors 1a and 1b. Negr1 and Iglon5 transcripts have uniform 5' region, suggesting single promoter. Iglon5, the recently characterized family member, shares high level of conservation and structural qualities characteristic to IgLON family such as N-terminal signal peptide, three Ig domains, and GPI anchor binding site. By using custom 5'-isoform-specific TaqMan gene-expression assay, we demonstrated heterogeneous expression of IgLON transcripts in different areas of mouse brain and several-fold lower expression in selected tissues outside central nervous system. As an example, the expression of IgLON transcripts in urogenital and reproductive system is in line with repeated reports of urogenital tumors accompanied by mutations in IgLON genes. Considering the high levels of intra-family homology shared by IgLONs, we investigated potential compensatory effects at the level of IgLON isoforms in the brains of mice deficient of one or two family members. We found that the lack of IgLONs is not compensated by a systematic quantitative increase of the other family members. On the contrary, the expression of Ntm 1a transcript and NEGR1 protein was significantly reduced in the frontal cortex of Lsamp-deficient mice suggesting that the expression patterns within IgLON family are balanced coherently. The actions of individual IgLONs, however, can be antagonistic as demonstrated by differential expression of Syp in deletion mutants of IgLONs. In conclusion, we show that the genomic twin-promoter structure has impact on both anatomical distribution and intra-family interactions of IgLON family members. Remarkable variety in the activity levels of 1a and 1b promoters both in the brain and in other tissues, suggests complex functional regulation of IgLONs by alternative signal peptides driven by 1a and 1b promoters.Peer reviewe

Female rat sexual behavior is unaffected by perinatal fluoxetine exposure

Serotonin plays an important role in adult female sexual behavior, however little is known about the influence of serotonin during early development on sexual functioning in adulthood. During early development, serotonin acts as neurotrophic factor, while it functions as a modulatory neurotransmitter in adulthood. The occurrence of serotonin release, could thus have different effects on behavioral outcomes, depending on the developmental period in which serotonin is released. Because serotonin is involved in the development of the HPG axis which is required for puberty establishment, serotonin could also alter expression patterns of for instance the estrogen receptor ɑ (ERɑ). The aim of our study was to investigate the effects of increased serotonin levels during early development on adult female rat sexual behavior during the full behavioral estrus in a seminatural environment. To do so, rats were perinatally exposed with the selective serotonin reuptake inhibitor (SSRI) fluoxetine (10 mg/kg FLX) and sexual performance was tested during adulthood. All facets of female sexual behavior between the first and last lordosis (behavioral estrus), and within each copulation bout of the behavioral estrus were analyzed. Besides the length and onset of the behavioral estrus and the sexual behaviors patterns, other social and conflict behavior were also investigated. In addition, we studied the effects of perinatal FLX exposure on ERɑ expression patterns in the medial preoptic nucleus, ventromedial nucleus of the hypothalamus, medial amygdala, bed nucleus of the stria terminalis, and the dorsal raphé nucleus. The results showed that perinatal fluoxetine exposure has no effect on adult female sexual behavior. The behavioral estrus of FLX-females had the same length and pattern as CTR-females. In addition, FLX- and CTR-females showed the same amount of paracopulatory behavior and lordosis, both during the full behavioral estrus and the "most active bout". Furthermore, no differences were found in the display of social and conflict behaviors, nor in ERɑ expression patterns in the brain. We conclude that increases in serotonin levels during early development do not have long-term consequences for female sexual behavior in adulthood.</p