Yegor Malashichev | Saint-Petersburg State University (original) (raw)
Papers by Yegor Malashichev
Laterality of brain and behavior at the individual and/or group level is a characteristic of all ... more Laterality of brain and behavior at the individual and/or group level is a characteristic of all vertebrate classes, including amphibians. It is well recognized that the right-eye/left-hemisphere system is more efficient in discrimination of edible and non-edible items. However, the ontogenesis of this or other lateralized responses has rarely been investigated. Here we present the first evidence of ontogenesis of right-eye/left-hemisphere response to live food in the Mexican axolotl, Ambystoma mexicanum. Furthermore, we test a possible influence of mirror images imitating the presence of conspecifics on laterality of the reaction to food, as well as on the growth and development of axolotls; we then compare the results to those known for anuran tadpoles. We placed the newly hatched axolotls into aquaria either with transparent or mirror walls individually
(first experiment), or in a group of 25 animals (second experiment). The
larvae were fed Artemia salina nauplii and regularly scored for the number and direction (either left or right) of their attacks towards the prey. Body length was measured twice a month. The statistically significant lateralized response to food was first detected in only three-week-old larvae and was right-sided, suggesting processing of visual information in the left brain hemisphere. At the same age, the left hemisphere seems to start its specialization in more efficient perception of prey. In both experiments we found a significant difference between the larvae growing in the transparent and mirror aquaria, with a tendency
towards a stronger right-sided lateralization in the mirror aquaria. Also,
the mirror walls inhibited larval growth, especially at the age of 60–75 days. A similar phenomenon is known in overcrowding of anuran tadpoles, which is discussed in terms of visual brain stimulation.
Brain and behavioral asymmetries are often associated with neurodevelop-mental disorders, but hav... more Brain and behavioral asymmetries are often associated with neurodevelop-mental disorders, but have yet uncovered genetic and developmental mechanisms. A recent study by Vingerhoets and colleagues (2018), published in Brain Structure and Function, examined neural structural and functional asymmetries in a cohort of patients with situs inversus totalis, with and without primary cili-arly dyskinesia as a second diagnosis. The authors showed a potential for independent randomization of handedness, language dominance, and visceral laterality; this provides the first experimental hint that different mechanisms for symmetry breaking and molecular cascades may be involved in producing asymmetry of body and brain.
Psychiatry Research, 2015
Schizophrenia is a debilitating psychiatric disorder, affecting approximately 1% of the human pop... more Schizophrenia is a debilitating psychiatric disorder, affecting approximately 1% of the human population. Mostly genetic factors contribute to schizophrenia, but the genetics are complex and various aspects of brain functioning and structure, from development to synapse plasticity, seem to be involved in the pathogenesis. The goal of the study was to look for novel mutations in genes, implicated in molecular networks, important in schizophrenia. In the study four candidate genes taking part in the WNT signaling pathway were analyzed by sequencing in a cohort of 87 schizophrenia patients from Saint Petersburg, Russia. The gene list included CTNNB1 (beta-catenin), GSK3B, WNT2B and WNT7B. The impact of discovered variants on the protein function was analyzed in silico. We found three variants in the genes CTNNB1 and WNT7B, absent in healthy controls, including 212 controls from the same geographic area. The novel mutation c.1943A>G (p.N648S) in CTNNB1 seems to be the best candidate for disease-associated mutation in this study, as it damages the protein product in silico. This is the first study reporting mutations in CTNNB1 in schizophrenia.
Psychiatric Genetics, 2014
Schizophrenia is a severe psychiatric disorder, affecting ∼1% of the human population. The geneti... more Schizophrenia is a severe psychiatric disorder, affecting ∼1% of the human population. The genetic contribution to schizophrenia is significant, but the genetics are complex and many aspects of brain functioning, from neural development to synapse structure, seem to be involved in the pathogenesis. A novel way to study the molecular causes of schizophrenia is to study the genetics of left-right (LR) brain asymmetry, the disease feature often observed in schizophrenic patients. In this study, we analyzed by sequencing five candidate LR cerebral asymmetry genes in a cohort of 95 schizophrenia and schizotypal disorder patients from Saint Petersburg, Russia. The gene list included LMO4, LRRTM1, FOXP2, the PCDH11X/Y gene pair, and SRY. We found 17 previously unreported variants in the genes LRRTM1, FOXP2, LMO4, and PCDH11X in the 3'-UTR and 5'-UTR. The variants might contribute toward an altered mRNA processing, which could lead to altered mRNA amounts in developing neurons of the brain and establishment of an incorrect LR asymmetry profile. This is the first study in which multiple candidate genes for cerebral LR asymmetry and schizophrenia have been analyzed by sequencing. The approach to study the genetics of schizophrenia from the perspective of an LR cerebral asymmetry disturbance deserves more attention.
Robust lateralization in forelimb use has recently been found in bipedal, but not quadrupedal, ma... more Robust lateralization in forelimb use has recently been found in bipedal, but not quadrupedal, marsupial mammals. The link between bipedality and handedness, occurring in both marsupials and primates, remains to be investigated. To shed light on the developmental origins of marsupial manual lateralization, infants of macropod marsupials were examined before and shortly after the acquisition of habitual bipedal posture and locomotion. Forelimb preferences were assessed in natural, not artificially evoked, behaviors of infant red-necked wallaby in the wild and infant eastern gray kangaroo in free-ranging captivity. Pouch young of both species showed population-level left-forelimb preference when manipulating food objects, such as leaves and grass blades. This result provides the first report of lateralization in pouch young marsupials and rare evidence of lateralized manual activity in early mammalian ontogenesis. Young-at-foot juveniles of eastern gray kangaroo preferred to use the left forelimb to manipulate the mother's pouch edge as previously shown for red-necked wallaby. In both species, the direction of biases in manipulative behavior for young-at-foot and pouch young was the same as in adults. Forelimb preferences in offspring were positively correlated with the forelimb preferences of their mothers. Our results strongly suggest that the emergence of individual and population-level forelimb preferences in macropod infants precedes the onset of independent standing and locomotion. In all probability, manual lateralization in bipedal marsupials, such as kangaroos and wallabies, is not determined by the acquisition of habitual bipedality in the course of ontogenesis.
Neural crest (NC) is an established source for many endochondral and intramem-branous bones in th... more Neural crest (NC) is an established source for many endochondral and intramem-branous bones in the skull and postcranial skeleton in vertebrates. Neural crest cells also contribute to the trapezius/cleidohyoideus muscle attachment sites on the shoulder girdle of the mouse, where they are found in the scapula, clavicle, and sternum. In the avian shoulder girdle, NC cells from the level of the first two cranial−most somites were only found so far in the clavicle, while in the axolotl, the NC contribution to the shoulder girdle was not found at all. In this study we aimed to determine whether NC cells caudal to the level of the second somite contribute to the cartilaginous shoulder girdle in birds and to analyse the phylogenetic distribution of NC cells in the vertebrate shoulder girdle. Homotopic quail to chick embryos and GFP+ to white chick embryos transplantations of the neural tube including presumptive NC, as well as immunohistochemical detection of NC markers, such as HNK-1 and PDGFRα revealed no contribution of NC cells from somite levels 3−27 to the skeletal elements of the shoulder girdle, including, but not restricting to muscle attachment sites, despite abundance of other NC derivatives. Thus, in birds, NC does not contribute to the formation of the cartilaginous shoulder girdle. The negative result is discussed in a broad evolutionary aspect. It supports the notion of the uniqueness of NC contribution to the variety of endochondral bones in mice (or mammals). In other vertebrates, including birds, only the cells of the cranial NC seem to migrate to the shoulder girdle and contribute to the intramembranous clavicles and/or interclavicle. We critically evaluate the existing hypotheses on evolution of NC contribution to the shoulder girdle in vertebrates.
Left-cradling bias is a distinctive feature of maternal behaviour in humans and great apes, but i... more Left-cradling bias is a distinctive feature of maternal behaviour
in humans and great apes, but its evolutionary origin remains
unknown. In 11 species of marine and terrestrial mammal, we
demonstrate consistent patterns of lateralization in mother–
infant interactions, indicating right hemisphere dominance
for social processing. In providing clear evidence that lateralized
positioning is beneficial in mother–infant interactions,
our results illustrate a significant impact of lateralization on
individual fitness.
Highlights d Bipedal macropod marsupials display population-level leftforelimb preference d Later... more Highlights d Bipedal macropod marsupials display population-level leftforelimb preference d Lateralization in bipedal marsupials is consistent across multiple behaviors d Bipedal marsupials show stronger manual lateralization than quadrupeds d Species differences in lateralization are not explained by phylogenetic relations Correspondence y.malashichev@spbu.ru In Brief Strongly pronounced handedness is traditionally considered to be a distinctive human trait. Giljov et al. show forelimb preferences in kangaroos, comparable in strength with human handedness, but oppositely directed. The contrast in manual lateralization between bipedal and quadrupedal marsupials emphasizes the link between posture and handedness. SUMMARY Recent studies have demonstrated a close resemblance between some handedness patterns in great apes and humans [1-3]. Despite this, comparative systematic investigations of manual lateralization in non-primate mammals are very limited [4, 5]. Among mammals, robust population-level handedness is still considered to be a distinctive human trait [6, 7].
in humans and great apes, but its evolutionary origin remains unknown. In 11 species of marine an... more in humans and great apes, but its evolutionary origin remains
unknown. In 11 species of marine and terrestrial mammal, we
demonstrate consistent patterns of lateralization in mother–
infant interactions, indicating right hemisphere dominance
for social processing. In providing clear evidence that lateralized
positioning is beneficial in mother–infant interactions,
our results illustrate a significant impact of lateralization on
individual fitness.
A review of the herpetofauna of the «Belogorye» Natural Reserve was carried out for the «Les na V... more A review of the herpetofauna of the «Belogorye» Natural Reserve was carried out for the «Les na Vorskle » and «Ostrasyev Yar» territories. Twelve amphibian and nine reptilian species were recorded on this territory from 1927 till 2006. Extinction of two amphibian species and two reptile ones was revealed, which was supposed to be a result of climate aridization and anthropogenic pressure intensification.
Current Biology, 2015
Highlights d Bipedal macropod marsupials display population-level leftforelimb preference d Later... more Highlights d Bipedal macropod marsupials display population-level leftforelimb preference d Lateralization in bipedal marsupials is consistent across multiple behaviors d Bipedal marsupials show stronger manual lateralization than quadrupeds d Species differences in lateralization are not explained by phylogenetic relations Correspondence y.malashichev@spbu.ru In Brief Strongly pronounced handedness is traditionally considered to be a distinctive human trait. Giljov et al. show forelimb preferences in kangaroos, comparable in strength with human handedness, but oppositely directed. The contrast in manual lateralization between bipedal and quadrupedal marsupials emphasizes the link between posture and handedness. SUMMARY Recent studies have demonstrated a close resemblance between some handedness patterns in great apes and humans [1-3]. Despite this, comparative systematic investigations of manual lateralization in non-primate mammals are very limited [4, 5]. Among mammals, robust population-level handedness is still considered to be a distinctive human trait [6, 7].
PLoS ONE, 2012
Background: Factors determining patterns of laterality manifestation in mammals remain unclear. I... more Background: Factors determining patterns of laterality manifestation in mammals remain unclear. In primates, the upright posture favours the expression of manual laterality across species, but may have little influence within a species. Whether the bipedalism acts the same in non-primate mammals is unknown. Our recent findings in bipedal and quadrupedal marsupials suggested that differences in laterality pattern, as well as emergence of manual specialization in evolution might depend on species-specific body posture. Here, we evaluated the hypothesis that the postural characteristics are the key variable shaping the manual laterality expression across mammalian species.
BMC Evolutionary Biology, 2013
Background: Acquisition of upright posture in evolution has been argued to facilitate manual late... more Background: Acquisition of upright posture in evolution has been argued to facilitate manual laterality in primates. Owing to the high variety of postural habits marsupials can serve as a suitable model to test whether the speciestypical body posture shapes forelimb preferences in non-primates or this phenomenon emerged only in the course of primate evolution. In the present study we aimed to explore manual laterality in marsupial quadrupeds and compare them with the results in the previously studied bipedal species. Forelimb preferences were assessed in captive grey short-tailed opossum (Monodelphis domestica) and sugar glider (Petaurus breviceps) in four different types of unimanual behaviour per species, which was not artificially evoked. We examined the possible effects of sex, age and task, because these factors have been reported to affect motor laterality in placental mammals. Results: In both species the direction of forelimb preferences was strongly sex-related. Male grey short-tailed opossums showed right-forelimb preference in most of the observed unimanual behaviours, while male sugar gliders displayed only a slight, not significant rightward tendency. In contrast, females in both species exhibited consistent group-level preference of the left forelimb. We failed to reveal significant differences in manual preferences between tasks of potentially differing complexity: reaching a stable food item and catching live insects, as well as between the body support and food manipulation. No influence of subjects' age on limb preferences was found. Conclusions: The direction of sex-related differences in the manual preferences found in quadrupedal marsupials seems to be not typical for placental mammals. We suggest that the alternative way of interhemispheric connection in absence of corpus callosum may result in a fundamentally distinct mechanism of sex effect on limb preferences in marsupials compared to placentals. Our data confirm the idea that non-primate mammals differ from primates in sensitivity to task complexity. Comparison of marsupial species studied to date indicate that the vertical body orientation and the bipedalism favor the expression of individual-and population-level forelimb preferences in marsupials much like it does in primates. Our findings give the first evidence for the effect of species-typical posture on the manual laterality in non-primate mammals.
PLoS ONE, 2010
Background: Behavioral laterality is known for a variety of vertebrate and invertebrate animals. ... more Background: Behavioral laterality is known for a variety of vertebrate and invertebrate animals. Laterality in social interactions has been described for a wide range of species including humans. Although evidence and theoretical predictions indicate that in social species the degree of population level laterality is greater than in solitary ones, the origin of these unilateral biases is not fully understood. It is especially poorly studied in the wild animals. Little is known about the role, which laterality in social interactions plays in natural populations. A number of brain characteristics make cetaceans most suitable for investigation of lateralization in social contacts.
Some animals, notably birds, preferentially approach and capture food items in their right visual... more Some animals, notably birds, preferentially approach and capture food items in their right visual field. However, this lateralised behaviour has not been studied extensively in anamniotes. Here we test eye preference during feeding for a fish, (Perccottus glenii; Teleostei, Perciformes), a newt, (Pleurodeles walti; Amphibia, Caudata), and a frog, (Xenopus laevis; Amphibia, Anura) using a test chamber that assesses reaction to visual stimuli while blocking olfactory and mechanical input. Both the fish and the newt showed right preferences in reactions to food items, but the frog did not. Our data extend our knowledge of the lateralised behaviours of vertebrates and are the first record of lateralised prey capture in a caudate amphibian. This finding dates back the history of the common pattern for visual lateralisation in vertebrates to Devonian, when the fish and quadruped lineages diverged.
Animal Behaviour, 2012
ABSTRACT
Animal Cognition, 2013
Visual lateralization in different aspects of social behaviour has been found for numerous specie... more Visual lateralization in different aspects of social behaviour has been found for numerous species of vertebrates ranging from fish to mammals. For inspection of a shoal mate, many fishes show a left eye-right hemisphere preference. Here, we tested the hypothesis that in fish, there is a key cue in the conspecific appearance, which elicits lateralized response to the whole image of the conspecific. In a series of eight experiments, we explored eye preferences in cryptic-coloured Amur sleeper, Perccottus glenii, fry. Fish displayed left-eye preferences at the population level for inspection of a group of conspecifics, their own mirror image, and a motionless flat model of a conspecific. In contrast, no population bias was found for scrutinizing an empty environment or a moving cylinder. When fry were showed a model of a conspecific in a lateral view with the eye displaced from the head to the tail, they again showed a significant preference for left-eye use. On the other hand, 'eyeless' conspecific model elicited no lateralized viewing in fry. Finally, the left-eye preference was revealed for scrutiny of the image of a conspecific eye alone. We argue that in Amur sleeper fry, eye is the element of the conspecific image, which can serve as a 'key' for the initiation of lateralized social response. This key element may serve as a trigger for the rapid recognition of conspecifics in the left eye-right hemisphere system. Possible causes and advantages of lateralized perception of social stimuli and their key elements are discussed in the context of current theories of brain lateralization.
Behavioral Ecology and Sociobiology, 2013
Laterality of brain and behavior at the individual and/or group level is a characteristic of all ... more Laterality of brain and behavior at the individual and/or group level is a characteristic of all vertebrate classes, including amphibians. It is well recognized that the right-eye/left-hemisphere system is more efficient in discrimination of edible and non-edible items. However, the ontogenesis of this or other lateralized responses has rarely been investigated. Here we present the first evidence of ontogenesis of right-eye/left-hemisphere response to live food in the Mexican axolotl, Ambystoma mexicanum. Furthermore, we test a possible influence of mirror images imitating the presence of conspecifics on laterality of the reaction to food, as well as on the growth and development of axolotls; we then compare the results to those known for anuran tadpoles. We placed the newly hatched axolotls into aquaria either with transparent or mirror walls individually
(first experiment), or in a group of 25 animals (second experiment). The
larvae were fed Artemia salina nauplii and regularly scored for the number and direction (either left or right) of their attacks towards the prey. Body length was measured twice a month. The statistically significant lateralized response to food was first detected in only three-week-old larvae and was right-sided, suggesting processing of visual information in the left brain hemisphere. At the same age, the left hemisphere seems to start its specialization in more efficient perception of prey. In both experiments we found a significant difference between the larvae growing in the transparent and mirror aquaria, with a tendency
towards a stronger right-sided lateralization in the mirror aquaria. Also,
the mirror walls inhibited larval growth, especially at the age of 60–75 days. A similar phenomenon is known in overcrowding of anuran tadpoles, which is discussed in terms of visual brain stimulation.
Brain and behavioral asymmetries are often associated with neurodevelop-mental disorders, but hav... more Brain and behavioral asymmetries are often associated with neurodevelop-mental disorders, but have yet uncovered genetic and developmental mechanisms. A recent study by Vingerhoets and colleagues (2018), published in Brain Structure and Function, examined neural structural and functional asymmetries in a cohort of patients with situs inversus totalis, with and without primary cili-arly dyskinesia as a second diagnosis. The authors showed a potential for independent randomization of handedness, language dominance, and visceral laterality; this provides the first experimental hint that different mechanisms for symmetry breaking and molecular cascades may be involved in producing asymmetry of body and brain.
Psychiatry Research, 2015
Schizophrenia is a debilitating psychiatric disorder, affecting approximately 1% of the human pop... more Schizophrenia is a debilitating psychiatric disorder, affecting approximately 1% of the human population. Mostly genetic factors contribute to schizophrenia, but the genetics are complex and various aspects of brain functioning and structure, from development to synapse plasticity, seem to be involved in the pathogenesis. The goal of the study was to look for novel mutations in genes, implicated in molecular networks, important in schizophrenia. In the study four candidate genes taking part in the WNT signaling pathway were analyzed by sequencing in a cohort of 87 schizophrenia patients from Saint Petersburg, Russia. The gene list included CTNNB1 (beta-catenin), GSK3B, WNT2B and WNT7B. The impact of discovered variants on the protein function was analyzed in silico. We found three variants in the genes CTNNB1 and WNT7B, absent in healthy controls, including 212 controls from the same geographic area. The novel mutation c.1943A>G (p.N648S) in CTNNB1 seems to be the best candidate for disease-associated mutation in this study, as it damages the protein product in silico. This is the first study reporting mutations in CTNNB1 in schizophrenia.
Psychiatric Genetics, 2014
Schizophrenia is a severe psychiatric disorder, affecting ∼1% of the human population. The geneti... more Schizophrenia is a severe psychiatric disorder, affecting ∼1% of the human population. The genetic contribution to schizophrenia is significant, but the genetics are complex and many aspects of brain functioning, from neural development to synapse structure, seem to be involved in the pathogenesis. A novel way to study the molecular causes of schizophrenia is to study the genetics of left-right (LR) brain asymmetry, the disease feature often observed in schizophrenic patients. In this study, we analyzed by sequencing five candidate LR cerebral asymmetry genes in a cohort of 95 schizophrenia and schizotypal disorder patients from Saint Petersburg, Russia. The gene list included LMO4, LRRTM1, FOXP2, the PCDH11X/Y gene pair, and SRY. We found 17 previously unreported variants in the genes LRRTM1, FOXP2, LMO4, and PCDH11X in the 3'-UTR and 5'-UTR. The variants might contribute toward an altered mRNA processing, which could lead to altered mRNA amounts in developing neurons of the brain and establishment of an incorrect LR asymmetry profile. This is the first study in which multiple candidate genes for cerebral LR asymmetry and schizophrenia have been analyzed by sequencing. The approach to study the genetics of schizophrenia from the perspective of an LR cerebral asymmetry disturbance deserves more attention.
Robust lateralization in forelimb use has recently been found in bipedal, but not quadrupedal, ma... more Robust lateralization in forelimb use has recently been found in bipedal, but not quadrupedal, marsupial mammals. The link between bipedality and handedness, occurring in both marsupials and primates, remains to be investigated. To shed light on the developmental origins of marsupial manual lateralization, infants of macropod marsupials were examined before and shortly after the acquisition of habitual bipedal posture and locomotion. Forelimb preferences were assessed in natural, not artificially evoked, behaviors of infant red-necked wallaby in the wild and infant eastern gray kangaroo in free-ranging captivity. Pouch young of both species showed population-level left-forelimb preference when manipulating food objects, such as leaves and grass blades. This result provides the first report of lateralization in pouch young marsupials and rare evidence of lateralized manual activity in early mammalian ontogenesis. Young-at-foot juveniles of eastern gray kangaroo preferred to use the left forelimb to manipulate the mother's pouch edge as previously shown for red-necked wallaby. In both species, the direction of biases in manipulative behavior for young-at-foot and pouch young was the same as in adults. Forelimb preferences in offspring were positively correlated with the forelimb preferences of their mothers. Our results strongly suggest that the emergence of individual and population-level forelimb preferences in macropod infants precedes the onset of independent standing and locomotion. In all probability, manual lateralization in bipedal marsupials, such as kangaroos and wallabies, is not determined by the acquisition of habitual bipedality in the course of ontogenesis.
Neural crest (NC) is an established source for many endochondral and intramem-branous bones in th... more Neural crest (NC) is an established source for many endochondral and intramem-branous bones in the skull and postcranial skeleton in vertebrates. Neural crest cells also contribute to the trapezius/cleidohyoideus muscle attachment sites on the shoulder girdle of the mouse, where they are found in the scapula, clavicle, and sternum. In the avian shoulder girdle, NC cells from the level of the first two cranial−most somites were only found so far in the clavicle, while in the axolotl, the NC contribution to the shoulder girdle was not found at all. In this study we aimed to determine whether NC cells caudal to the level of the second somite contribute to the cartilaginous shoulder girdle in birds and to analyse the phylogenetic distribution of NC cells in the vertebrate shoulder girdle. Homotopic quail to chick embryos and GFP+ to white chick embryos transplantations of the neural tube including presumptive NC, as well as immunohistochemical detection of NC markers, such as HNK-1 and PDGFRα revealed no contribution of NC cells from somite levels 3−27 to the skeletal elements of the shoulder girdle, including, but not restricting to muscle attachment sites, despite abundance of other NC derivatives. Thus, in birds, NC does not contribute to the formation of the cartilaginous shoulder girdle. The negative result is discussed in a broad evolutionary aspect. It supports the notion of the uniqueness of NC contribution to the variety of endochondral bones in mice (or mammals). In other vertebrates, including birds, only the cells of the cranial NC seem to migrate to the shoulder girdle and contribute to the intramembranous clavicles and/or interclavicle. We critically evaluate the existing hypotheses on evolution of NC contribution to the shoulder girdle in vertebrates.
Left-cradling bias is a distinctive feature of maternal behaviour in humans and great apes, but i... more Left-cradling bias is a distinctive feature of maternal behaviour
in humans and great apes, but its evolutionary origin remains
unknown. In 11 species of marine and terrestrial mammal, we
demonstrate consistent patterns of lateralization in mother–
infant interactions, indicating right hemisphere dominance
for social processing. In providing clear evidence that lateralized
positioning is beneficial in mother–infant interactions,
our results illustrate a significant impact of lateralization on
individual fitness.
Highlights d Bipedal macropod marsupials display population-level leftforelimb preference d Later... more Highlights d Bipedal macropod marsupials display population-level leftforelimb preference d Lateralization in bipedal marsupials is consistent across multiple behaviors d Bipedal marsupials show stronger manual lateralization than quadrupeds d Species differences in lateralization are not explained by phylogenetic relations Correspondence y.malashichev@spbu.ru In Brief Strongly pronounced handedness is traditionally considered to be a distinctive human trait. Giljov et al. show forelimb preferences in kangaroos, comparable in strength with human handedness, but oppositely directed. The contrast in manual lateralization between bipedal and quadrupedal marsupials emphasizes the link between posture and handedness. SUMMARY Recent studies have demonstrated a close resemblance between some handedness patterns in great apes and humans [1-3]. Despite this, comparative systematic investigations of manual lateralization in non-primate mammals are very limited [4, 5]. Among mammals, robust population-level handedness is still considered to be a distinctive human trait [6, 7].
in humans and great apes, but its evolutionary origin remains unknown. In 11 species of marine an... more in humans and great apes, but its evolutionary origin remains
unknown. In 11 species of marine and terrestrial mammal, we
demonstrate consistent patterns of lateralization in mother–
infant interactions, indicating right hemisphere dominance
for social processing. In providing clear evidence that lateralized
positioning is beneficial in mother–infant interactions,
our results illustrate a significant impact of lateralization on
individual fitness.
A review of the herpetofauna of the «Belogorye» Natural Reserve was carried out for the «Les na V... more A review of the herpetofauna of the «Belogorye» Natural Reserve was carried out for the «Les na Vorskle » and «Ostrasyev Yar» territories. Twelve amphibian and nine reptilian species were recorded on this territory from 1927 till 2006. Extinction of two amphibian species and two reptile ones was revealed, which was supposed to be a result of climate aridization and anthropogenic pressure intensification.
Current Biology, 2015
Highlights d Bipedal macropod marsupials display population-level leftforelimb preference d Later... more Highlights d Bipedal macropod marsupials display population-level leftforelimb preference d Lateralization in bipedal marsupials is consistent across multiple behaviors d Bipedal marsupials show stronger manual lateralization than quadrupeds d Species differences in lateralization are not explained by phylogenetic relations Correspondence y.malashichev@spbu.ru In Brief Strongly pronounced handedness is traditionally considered to be a distinctive human trait. Giljov et al. show forelimb preferences in kangaroos, comparable in strength with human handedness, but oppositely directed. The contrast in manual lateralization between bipedal and quadrupedal marsupials emphasizes the link between posture and handedness. SUMMARY Recent studies have demonstrated a close resemblance between some handedness patterns in great apes and humans [1-3]. Despite this, comparative systematic investigations of manual lateralization in non-primate mammals are very limited [4, 5]. Among mammals, robust population-level handedness is still considered to be a distinctive human trait [6, 7].
PLoS ONE, 2012
Background: Factors determining patterns of laterality manifestation in mammals remain unclear. I... more Background: Factors determining patterns of laterality manifestation in mammals remain unclear. In primates, the upright posture favours the expression of manual laterality across species, but may have little influence within a species. Whether the bipedalism acts the same in non-primate mammals is unknown. Our recent findings in bipedal and quadrupedal marsupials suggested that differences in laterality pattern, as well as emergence of manual specialization in evolution might depend on species-specific body posture. Here, we evaluated the hypothesis that the postural characteristics are the key variable shaping the manual laterality expression across mammalian species.
BMC Evolutionary Biology, 2013
Background: Acquisition of upright posture in evolution has been argued to facilitate manual late... more Background: Acquisition of upright posture in evolution has been argued to facilitate manual laterality in primates. Owing to the high variety of postural habits marsupials can serve as a suitable model to test whether the speciestypical body posture shapes forelimb preferences in non-primates or this phenomenon emerged only in the course of primate evolution. In the present study we aimed to explore manual laterality in marsupial quadrupeds and compare them with the results in the previously studied bipedal species. Forelimb preferences were assessed in captive grey short-tailed opossum (Monodelphis domestica) and sugar glider (Petaurus breviceps) in four different types of unimanual behaviour per species, which was not artificially evoked. We examined the possible effects of sex, age and task, because these factors have been reported to affect motor laterality in placental mammals. Results: In both species the direction of forelimb preferences was strongly sex-related. Male grey short-tailed opossums showed right-forelimb preference in most of the observed unimanual behaviours, while male sugar gliders displayed only a slight, not significant rightward tendency. In contrast, females in both species exhibited consistent group-level preference of the left forelimb. We failed to reveal significant differences in manual preferences between tasks of potentially differing complexity: reaching a stable food item and catching live insects, as well as between the body support and food manipulation. No influence of subjects' age on limb preferences was found. Conclusions: The direction of sex-related differences in the manual preferences found in quadrupedal marsupials seems to be not typical for placental mammals. We suggest that the alternative way of interhemispheric connection in absence of corpus callosum may result in a fundamentally distinct mechanism of sex effect on limb preferences in marsupials compared to placentals. Our data confirm the idea that non-primate mammals differ from primates in sensitivity to task complexity. Comparison of marsupial species studied to date indicate that the vertical body orientation and the bipedalism favor the expression of individual-and population-level forelimb preferences in marsupials much like it does in primates. Our findings give the first evidence for the effect of species-typical posture on the manual laterality in non-primate mammals.
PLoS ONE, 2010
Background: Behavioral laterality is known for a variety of vertebrate and invertebrate animals. ... more Background: Behavioral laterality is known for a variety of vertebrate and invertebrate animals. Laterality in social interactions has been described for a wide range of species including humans. Although evidence and theoretical predictions indicate that in social species the degree of population level laterality is greater than in solitary ones, the origin of these unilateral biases is not fully understood. It is especially poorly studied in the wild animals. Little is known about the role, which laterality in social interactions plays in natural populations. A number of brain characteristics make cetaceans most suitable for investigation of lateralization in social contacts.
Some animals, notably birds, preferentially approach and capture food items in their right visual... more Some animals, notably birds, preferentially approach and capture food items in their right visual field. However, this lateralised behaviour has not been studied extensively in anamniotes. Here we test eye preference during feeding for a fish, (Perccottus glenii; Teleostei, Perciformes), a newt, (Pleurodeles walti; Amphibia, Caudata), and a frog, (Xenopus laevis; Amphibia, Anura) using a test chamber that assesses reaction to visual stimuli while blocking olfactory and mechanical input. Both the fish and the newt showed right preferences in reactions to food items, but the frog did not. Our data extend our knowledge of the lateralised behaviours of vertebrates and are the first record of lateralised prey capture in a caudate amphibian. This finding dates back the history of the common pattern for visual lateralisation in vertebrates to Devonian, when the fish and quadruped lineages diverged.
Animal Behaviour, 2012
ABSTRACT
Animal Cognition, 2013
Visual lateralization in different aspects of social behaviour has been found for numerous specie... more Visual lateralization in different aspects of social behaviour has been found for numerous species of vertebrates ranging from fish to mammals. For inspection of a shoal mate, many fishes show a left eye-right hemisphere preference. Here, we tested the hypothesis that in fish, there is a key cue in the conspecific appearance, which elicits lateralized response to the whole image of the conspecific. In a series of eight experiments, we explored eye preferences in cryptic-coloured Amur sleeper, Perccottus glenii, fry. Fish displayed left-eye preferences at the population level for inspection of a group of conspecifics, their own mirror image, and a motionless flat model of a conspecific. In contrast, no population bias was found for scrutinizing an empty environment or a moving cylinder. When fry were showed a model of a conspecific in a lateral view with the eye displaced from the head to the tail, they again showed a significant preference for left-eye use. On the other hand, 'eyeless' conspecific model elicited no lateralized viewing in fry. Finally, the left-eye preference was revealed for scrutiny of the image of a conspecific eye alone. We argue that in Amur sleeper fry, eye is the element of the conspecific image, which can serve as a 'key' for the initiation of lateralized social response. This key element may serve as a trigger for the rapid recognition of conspecifics in the left eye-right hemisphere system. Possible causes and advantages of lateralized perception of social stimuli and their key elements are discussed in the context of current theories of brain lateralization.
Behavioral Ecology and Sociobiology, 2013