11 resultados para Animal cognition
em Helda - Digital Repository of University of Helsinki
Resumo:
Humans are a social species with the internal capability to process social information from other humans. To understand others behavior and to react accordingly, it is necessary to infer their internal states, emotions and aims, which are conveyed by subtle nonverbal bodily cues such as postures, gestures, and facial expressions. This thesis investigates the brain functions underlying the processing of such social information. Studies I and II of this thesis explore the neural basis of perceiving pain from another person s facial expressions by means of functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG). In Study I, observing another s facial expression of pain activated the affective pain system (previously associated with self-experienced pain) in accordance with the intensity of the observed expression. The strength of the response in anterior insula was also linked to the observer s empathic abilities. The cortical processing of facial pain expressions advanced from the visual to temporal-lobe areas at similar latencies (around 300 500 ms) to those previously shown for emotional expressions such as fear or disgust. Study III shows that perceiving a yawning face is associated with middle and posterior STS activity, and the contagiousness of a yawn correlates negatively with amygdalar activity. Study IV explored the brain correlates of interpreting social interaction between two members of the same species, in this case human and canine. Observing interaction engaged brain activity in very similar manner for both species. Moreover, the body and object sensitive brain areas of dog experts differentiated interaction from noninteraction in both humans and dogs whereas in the control subjects, similar differentiation occurred only for humans. Finally, Study V shows the engagement of the brain area associated with biological motion when exposed to the sounds produced by a single human being walking. However, more complex pattern of activation, with the walking sounds of several persons, suggests that as the social situation becomes more complex so does the brain response. Taken together, these studies demonstrate the roles of distinct cortical and subcortical brain regions in the perception and sharing of others internal states via facial and bodily gestures, and the connection of brain responses to behavioral attributes.
Resumo:
Neuronal ceroid lipofuscinoses (NCLs) are a family of inherited pediatric neurodegenerative disorders, leading to retinal degeneration, death of selective neuronal populations and accumulation of autofluorscent ceroid-lipopigments. The clinical manifestations are generally similar in all forms. The Finnish variant late infantile neuronal ceroid lipofuscinosis (vLINCLFin) is a form of NCL, especially enriched in the Finnish population. The aim of this thesis was to analyse the brain pathology of vLINCLFin utilising the novel Cln5-/- mouse model. Gene expression profiling of the brains of already symptomatic Cln5-/- mice revealed that inflammation, neurodegeneration and defects in myelinization are the major characteristics of the later stages of the disease. Histological characterization of the brain pathology confirmed that the thalamocortical system is affected in Cln5-/- mice, similarly to the other NCL mouse models. However, whereas the brain pathology in all other analyzed NCL mice initiate in the thalamus and spread only months later to the cortex, we observed that the sequence of events is uniquely reversed in Cln5-/- mice; beginning in the cortex and spreading to the thalamus only months later. We could also show that even though neurodegeneration is inititated in the cortex, reactive gliosis and loss of myelin are evident in specific nuclei of the thalamus already in the 1 month old brain. To obtain a deeper insight into the disturbed metabolic pathways, we performed gene expression profiling of presymptomatic mouse brains. We validated these findings with immunohistological analyses, and could show that cytoskeleton and myelin were affected in Cln5-/- mice. Comparison of gene expression profiling results of Cln5-/- and Cln1-/- mice, further highlighted that these two NCL models share a common defective pathway, leading to disturbances in the neuronal growth cone and cytoskeleton. Encouraged by the evidence of this defected pathway, we analyzed the molecular interactions of NCL-proteins and observed that Cln5 and Cln1/Ppt1 proteins interact with each other. Furthermore, we demonstrated that Cln5 and Cln1/Ppt1 share an interaction partner, the F1-ATP synthase, potentially linking both vLINCLFIN and INCL diseases to disturbed lipid metabolism. In addition, Cln5 was shown to interact with other NCL proteins; Cln2, Cln3, Cln6 and Cln8, implicating a central role for Cln5 in the NCL pathophysiology. This study is the first to describe the brain pathology and gene expression changes in the Cln5-/- mouse. Together the findings presented in this thesis represent novel information of the disease processes and the molecular mechanisms behind vLINCLFin and have highlighted that vLINCLFin forms a very important model to analyze the pathophysiology of NCL diseases.
Resumo:
Major advances in the treatment of preterm infants have occurred during the last three decades. Survival rates have increased, and the first generations of preterm infants born at very low birth weight (VLBW; less than 1500 g) who profited from modern neonatal intensive care are now in young adulthood. The literature shows that VLBW children achieve on average lower scores on cognitive tests, even after exclusion of individuals with obvious neurosensory deficits. Evidence also exists for an increased risk in VLBW children for various neuropsychiatric disorders such as attention-deficit hyperactivity disorder (ADHD) and related behavioral symptoms. Up till now, studies extending into adulthood are sparse, and it remains to be seen whether these problems persist into adulthood. The aim of this thesis was to study ADHD-related symptoms and cognitive and executive functioning in young adults born at VLBW. In addition, we aimed to study sleep disturbances, known to adversely affect both cognition and attention. We hypothesized that preterm birth at VLBW interferes with early brain development in a way that alters the neuropsychological phenotype; this may manifest itself as ADHD symptoms and impaired cognitive abilities in young adulthood. In this cohort study from a geographically defined region, we studied 166 VLBW adults and 172 term-born controls born from 1978 through 1985. At ages 18 to 27 years, the study participants took part in a clinic study during which their physical and psychological health was assessed in detail. Three years later, 213 of these individuals participated in a follow-up. The current study is part of a larger research project (The Helsinki Study of Very Low Birth Weight Adults), and the measurements of interest for this particular study include the following: 1) The Adult Problem Questionnaire (APQ), a self-rating scale of ADHD-related symptoms in adults; 2) A computerized cognitive test battery designed for population studies (CogState®) which measures core cognitive abilities such as reaction time, working memory, and visual learning; 3) Sleep assessment by actigraphy, the Basic Nordic Sleep Questionnaire, and the Morningness-Eveningness Questionnaire. Actigraphs are wrist-worn accelerometers that separate sleep from wakefulness by registering body movements. Contrary to expectations, VLBW adults as a group reported no more ADHD-related behavioral symptoms than did controls. Further subdivision of the VLBW group into SGA (small for gestational age) and AGA (appropriate for gestational age) subgroups, however, revealed more symptoms on ADHD subscales pertaining to executive dysfunction and emotional instability among those born SGA. Thus, it seems that intrauterine growth retardation (for which SGA served as a proxy) is a more essential predictor for self-perceived ADHD symptoms in adulthood than is VLBW birth as such. In line with observations from other cohorts, the VLBW adults reported less risk-taking behavior in terms of substance use (alcohol, smoking, and recreational drugs), a finding reassuring for the VLBW individuals and their families. On the cognitive test, VLBW adults free from neurosensory deficits had longer reaction times than did term-born peers on all tasks included in the test battery, and lower accuracy on the learning task, with no discernible effect of SGA status over and above the effect of VLBW. Altogether, on a group level, even high-functioning VLBW adults show subtle deficits in psychomotor processing speed, visual working memory, and learning abilities. The sleep studies provided no evidence for differences in sleep quality or duration between the two groups. The VLBW adults were, however, at more than two-fold higher risk for sleep-disordered breathing (in terms of chronic snoring). Given the link between sleep-disordered breathing and health sequelae, these results suggest that VLBW individuals may benefit from an increased awareness among clinicians of this potential problem area. An unexpected finding from the sleep studies was the suggestion of an advanced sleep phase: The VLBW adults went to bed earlier according to the actigraphy registrations and also reported earlier wake-up times on the questionnaire. In further study of this issue in conjunction with the follow-up three years later, the VLBW group reported higher levels of morningness propensity, further corroborating the preliminary findings of an advanced sleep phase. Although the clinical implications are not entirely clear, the issue may be worth further study, since circadian rhythms are closely related to health and well-being. In sum, we believe that increased understanding of long-term outcomes after VLBW, and identification of areas and subgroups that are particularly vulnerable, will allow earlier recognition of potential problems and ultimately lead to improved prevention strategies.
Resumo:
Background: Type 2 diabetes is linked to several complications which add to both physical and mental distress. Depression is a common co-morbidity of diabetes which can occur both as a cause and a consequence of type 2 diabetes. Depression has been shown to correlate with glucose regulation and treating depression might prove beneficial for glucose regulation as well as for mental well being. Another complication which might affect diabetes management is cognitive decline. Several risk factors and complications of diabetes might modify the risk for developing cognitive impairment, which is increased 1.5 times among subjects with type 2 diabetes. Type 2 diabetes, depression and impaired cognitive performance have all been linked to low birth weight. This thesis aimed to explore the effects and interactions of birth weight, depression and cognitive ability in relation to type 2 diabetes from a life course perspective. Subjects and methods: Studies I, II and V were part of the Helsinki Birth Cohort Study. 2003 subjects participated in an extensive clinical examination at an average age of 61 years. A standard glucose tolerance test (OGTT) was performed and depressive symptoms were assessed using the Beck Depression Inventory (BDI). In addition data was obtained from child welfare clinics and national registers. A subset of the cohort (n=1247) also performed a test on cognitive performance (CogState ®) at the average age of 64. Studies III and IV were randomised clinical trials where mildly depressed diabetic subjects were treated with paroxetine or placebo and the effect on metabolic parameters and quality of life was assessed. The first trial included 14 women and lasted 10 weeks, while the second trial included 43 subjects, both men and women, and lasted 6 months. Results: Type 2 diabetes was positively associated with the occurrence of depressive symptoms. Among diabetic subjects 23.6% had depressive symptoms, compared to 16.7% of subjects with normal glucose tolerance (OR = 1.77, p<0.001). Formal mediation analysis revealed that cardiovascular disease (CVD) is likely to act as a mediator in the association. Furthermore, low birth weight was found to modify the association between type 2 diabetes, CVD and depression. The association between BDI score and having type 2 diabetes or CVD was twice as strong in the subgroup with low birth weight (≤ 2500g) compared with the group with birth weight > 2500g (p for interaction 0.058). In the six months long randomised clinical trial (study IV) paroxetine had a transient beneficial effect on glycosylated haemoglobin A1c (GHbA1c) and quality of life when compared to placebo after three months of treatment. In study V we found that subjects with known diabetes had a consistently poorer level of cognitive performance than subjects with normal glucose tolerance in most of the tested cognitive domains. This effect was further amplified among those born with a small birth weight (p for interaction 0.002). Conclusions: Type 2 diabetes is associated with a higher occurrence of depressive symptoms compared to subjects with normal glucose tolerance. This association is especially strong among subjects with CVD and those born with a low birth weight. Treating depressed diabetic subjects with paroxetine has no long term effect on glucose regulation. Physicians should be aware of depression as an important co-morbidity of type 2 diabetes. Both depression and the cognitive decline often seen among diabetic subjects are increased if the subject is born with a low birth weight. Physicians should recognise low birth weight as an additional risk factor and modifier of diabetic complications.
Resumo:
The nature of a burial is always ritualistic. This is often forgotten when dealing with Finnish inhumation burials containing animal bones. Only the animal bones found close to the deceased have traditionally been thought to have a ritualistic purpose. The animal bones found in the filling of the grave, which is still part of the burial, has on the other hand, often been neglected in the previous research. In this Master s thesis I will discuss the function and interpretation of animal bones in graves. The base of this study is six sites, all of different nature, from Finland. Luistari in Eura is from the western coast and is dated to Late Iron Age (and possibly Medieval period), the Medieval hamlet of Finno is situated in Espoo which is situated on the southern coast. Two town burials, Turku and Porvoo, are also included in this study. The graves from Turku are dated to Late Medieval period and Early Renaissance, whereas the cemetery in Porvoo is from the 18th century. Visulahti in Mikkeli is from the Late Iron Age and represents Eastern Finnish burial tradition, the same as Suotniemi from Käkisalmi parish, which is nowadays part of Russia. While parts of the animal bones had already been analysed before, the author also analysed animal bones for the purpose of the present Master´s thesis. The bones were compared to the burial contexts, when possible. Based on the comparisons I have made interpretations which might explain the existence of animal bones in the graves. The interpretations are among others sacrifice, commemoration meals and animal burials. The site could also have been a settlement site prior to the graves, thus the bones in the graves would belong to the settlement phase. When comparing the date of the studied sites, the town burials are later and the animal bones are probably related to previous or contemporary use of the sites as graveyards. On top of this there does not seem to be much difference in burial tradition between Eastern and Western Finland, although at least from the hamlet burials of Finno there are aspects that could be linked to Eastern burials. In making the interpretations I have taken into consideration the aspects of belief during different time periods when they could be accounted as relevant. Also the problems with bone preservation were relevant and challenging for the study. Often only the hardest substance of the skeleton, namely teeth, has been preserved. For this reason the quality of the archaeological documentation was a key issue in this study. In producing quality interpretations of the animal bones in graves, the bones, contexts and their relationship to the surrounding site should be documented with care.
Resumo:
Kirjallisuusosa: Alzheimerin taudin hoitoon olisi tarvetta uusille taudinkulkuun vaikuttaville lääkeaineille. Niiden kehittämiseksi tarvitaan eläinmalleja, joissa esiintyy taudin patofysiologisia piirteitä. Rottamalleista vanhemmat skopolamiini- tai MK-801-häirintä sekä ikääntyneiden rottien käyttö eivät kovin hyvin vastaa taudin patofysiologiaa, vaikka niissä eläimen muisti käyttäytymiskokeissa onkin heikentynyt. Uudemmat transgeeniset rottamallit ja mallit, joissa annetaan Aβ:a aivoihin, ilmentävät huomattavasti paremmin Alzheimerin taudin kaltaista tilaa aivoissa ainakin Aβ:n osalta. Taupatofysiologiaa ei silti kummassakaan näistä malleista juuri esiinny. Toisaalta Aβ:lla näyttäisi olevan huomattavasti tau:ta suurempi rooli taudissa, joten sen ilmeneminen mallissa onkin keskeisempi tekijä. Nämä mallit ilmentävät melko suurelti osin yhtä hyvin Alzheimerin taudin patofysiologiaa. Aβ:n antaminen on hieman yksinkertaisempi suorittaa käytännössä, sillä siinä ei tarvitse luoda transgeenista kantaa. Toisaalta transgeenisessa mallissa Aβ-patofysiologia syntyy enemmän Alzheimerin taudin kaltaisesti solujen sisällä eikä valmiita aggregoituvia Aβ-peptidejä anneta ulkopuolelta aivoihin. Molemmat mallit ovat kuitenkin käyttökelpoisia, ja soveltuvat erityisesti Aβ:an vaikuttavien lääkeaineiden kehittämiseen. Kokeellinen osa: Kokeen tarkoituksena oli validoida kohotettu ristikko-sokkelo (elevated plus-maze, EPM) hiirillä kognitiomallina. Kokeessa käytettiin kahden koekerran (trial, T) menetelmää, jossa koekertojen pituus oli viisi minuuttia. Näin saatiin useita oppimista kuvaavia parametreja. Hiirille yritettiin saada muistihäiriö aikaviiveen avulla (koekertojen väli 1-18 vrk) tai antamalla muskariinireseptoriantagonistia skopolamiinia (0,1-0,8 mg/kg i.p.) 30 minuuttia ennen T1:tä. Nämä kokeet suoritettiin sekä C57BL/6J- että ICR:(CD-1)-hiirillä. Aikaviivekokeissa ainut ryhmä, jolla oli viitettä unohtamisesta, oli ICR:(CD-1)-hiirien 18 vrk:n ryhmä. Tämän perusteella tutkittiin vielä 21 vuorokauden aikaväli, mutta selvää muistihäiriötä ei esiintynyt. Skopolamiini ei häirinnyt muistia ICR:(CD-1)-hiirillä, mutta C57BL/6J-hiirillä 0,2 mg/kg:n annoksesta ylöspäin merkitsevä muistihäiriö esiintyi. Näin ollen jatkokokeissa käytettäväksi valittiin skopolamiinin annos 0,2 mg/kg C57BL/6J-hiirillä, ja siinä tutkittiin donepetsiilin (0,3, 0,8 ja 1,5 mg/kg s.c), memantiinin (5,0 ja 10,0 mg/kg s.c) ja kokeellisen 5-HT6-antagonistin SB742457:n (1,5 ja 6,0 mg/kg s.c) muistia parantavia vaikutuksia. Tutkittavat lääkeaineet annettiin 40 minuuttia ennen T1:tä ja skopolamiini 30 minuuttia ennen. Memantiinilla (5,0 mg/kg) oli selkeä skopolamiinin heikentämää kognitiota parantava vaikutus ja donepetsiilillakin (1,5 mg/kg) suuntaus tähän. Tulosten perusteella malli näyttäisi soveltuvan muisti- ja oppimisvaikutusten tutkimiseen käytettäväksi malliksi.