RECENT RESEARCH
Integrative Research using Non-consumptive Predator-Prey framework
In my recent commentary in the Journal of Experimental Biology, I propose an integrative generalized experimental framework based on a ubiquitous eco-evolutionary predator-prey interaction that can be used across multiple disciplines such as ecology, neuroscience, and development, etc., to answer some of the most important questions in biology. The insights gained from using this framework can potentially impact research in artificial intelligence, mental well-being, and biodiversity loss which are important contemporary challenges.
This commentary is also associated with an Early Career Researcher Spotlight Interview: journals.biologists.com/jeb/article/226/19/jeb246728/330708/ECR-Spotlight-Anuradha-Batabyal
In my recent commentary in the Journal of Experimental Biology, I propose an integrative generalized experimental framework based on a ubiquitous eco-evolutionary predator-prey interaction that can be used across multiple disciplines such as ecology, neuroscience, and development, etc., to answer some of the most important questions in biology. The insights gained from using this framework can potentially impact research in artificial intelligence, mental well-being, and biodiversity loss which are important contemporary challenges.
This commentary is also associated with an Early Career Researcher Spotlight Interview: journals.biologists.com/jeb/article/226/19/jeb246728/330708/ECR-Spotlight-Anuradha-Batabyal
Rapid and dynamic colour change in Agamidae
Dynamic colour change is widespread in ectothermic animals, but has primarily been studied in the context of background matching. For most species, we lack quantitative data on the extent of colour change across different contexts. It is also unclear
whether and how colour change varies across body regions, and how overall sexual dichromatism relates to the extent of individual colour change. We measures reflectance in response to different stimuli for males and females of six species of agamid lizards (Agamidae, sister family to Chameleonidae) comprising three closely related species pairs. We estimated overall
sexual dichromatism based on the area of non-overlapping male and female colour volumes. As expected, males had larger colour volumes than females, but the extent of colour change in males differed between species and between body regions.
Notably, species that were most sexually dichromatic were not necessarily those in which males showed the greatest individual colour change. Our results indicate that the extent of colour change is independent of the degree of sexual dichromatism and
demonstrate that colour change on different body regions can vary substantially even between pairs of closely related species.
Research article: Publications
Development of instinct from learning
Organisms evolve adaptive strategies to adjust to rapidly changing environmental stressors. Predation pressure is one of the strongest selective forces and organisms respond to predatory threats via innate and learned responses. We utilized a natural, experimental set-up, where two lakes Stoney and Margo in Canada containing natural populations of the prey Lymnaea stagnalis differed in the presence and absence of an invasive, predatory Northern crayfish. We exploited the contrast in the predation backgrounds of the snail populations from the two lakes to find that 1) predator recognition in predator-experienced snails is innate, 2) predator-naive snails learned to recognize the novel predator even after a brief exposure to predator cues highlighting the role of learning in combating invasive predators and the critical time-window during development that accounts for predator recognition, and 3) the learning and predator detection mechanism in predator-naive snails are not transmitted to successive generations. The population variation observed in the predator-detection mechanism may be due to the past and current experience of predators in one population over the other. We find an interesting study system to address how fear learning occurs and have now also found gene expression differences between these populations that would finally help us understand how instinct evolves from learning.
Research article: Publications
Organisms evolve adaptive strategies to adjust to rapidly changing environmental stressors. Predation pressure is one of the strongest selective forces and organisms respond to predatory threats via innate and learned responses. We utilized a natural, experimental set-up, where two lakes Stoney and Margo in Canada containing natural populations of the prey Lymnaea stagnalis differed in the presence and absence of an invasive, predatory Northern crayfish. We exploited the contrast in the predation backgrounds of the snail populations from the two lakes to find that 1) predator recognition in predator-experienced snails is innate, 2) predator-naive snails learned to recognize the novel predator even after a brief exposure to predator cues highlighting the role of learning in combating invasive predators and the critical time-window during development that accounts for predator recognition, and 3) the learning and predator detection mechanism in predator-naive snails are not transmitted to successive generations. The population variation observed in the predator-detection mechanism may be due to the past and current experience of predators in one population over the other. We find an interesting study system to address how fear learning occurs and have now also found gene expression differences between these populations that would finally help us understand how instinct evolves from learning.
Research article: Publications
Snail as a model system for cognitive research
Lymnaea stagnalis (the great pond snail) serves as an excellent model system for cognitive behavioural research because it shows both simple and complex associative learning and also has a simple nervous system which allows us to investigate the role of specific neurons and neuronal circuits that function in memory formation, storage and recall. The two robust and spontaneous behaviours that we use for our experimental tests are feeding response and breathing response. Lymnaea is a bimodal breather obtaining oxygen either through their skin or respiratory orifice (pneumostome). We train snails under an Operant conditioning paradigm where we poke the pneumostome as the snails come up to breathe and the snails have to learn not to open the pneumostome in further memory trials.
The feeding circuit is more complex that the respiratory circuit and thus research from our lab has focused on the three neuron network that drives the respiratory circuit. We also use the central nervous system to quantify expression of specific mRNAs that play a role in learning and memory (such as Serotonergic and dopaminergic system, Neuroplasticity genes: CREB, GRIN, Heat shock proteins:HSPs).
Research article: Publications
Lymnaea stagnalis (the great pond snail) serves as an excellent model system for cognitive behavioural research because it shows both simple and complex associative learning and also has a simple nervous system which allows us to investigate the role of specific neurons and neuronal circuits that function in memory formation, storage and recall. The two robust and spontaneous behaviours that we use for our experimental tests are feeding response and breathing response. Lymnaea is a bimodal breather obtaining oxygen either through their skin or respiratory orifice (pneumostome). We train snails under an Operant conditioning paradigm where we poke the pneumostome as the snails come up to breathe and the snails have to learn not to open the pneumostome in further memory trials.
The feeding circuit is more complex that the respiratory circuit and thus research from our lab has focused on the three neuron network that drives the respiratory circuit. We also use the central nervous system to quantify expression of specific mRNAs that play a role in learning and memory (such as Serotonergic and dopaminergic system, Neuroplasticity genes: CREB, GRIN, Heat shock proteins:HSPs).
Research article: Publications
Configural Learning and role of flavonoids in memory enhancement
Configural learning (CL) is a form of higher order associative learning wherein when snails experience two contrasting stimuli together such as predatory odour (crayfish effluent: predator of snails) and food odour (C: carrot odour) they learn and associate risk with food. This kind of learning involves a decision making as the two stimuli invoke opposite responses and animals need to decide for how long to avoid food as there exists an energy tradeoff. The memory for CL has been shown to last 3h. However, when snails are exposed to certain plant favonoids such as Green tea or Quercetin (found in several fruits and vegetables) the memory for CL is enhanced and now the snails avoid food for longer duration. This long-term memory might result due to effects of these plant favonoids on several molecular pathways that enhance memory formation. We found that one such molecule that is essential for long-term memory formation CREB (cyclic AMP response element binding protein) is upregulated by quercetin in the central nervous system of Lymnaea stagnalis.
Research article: Publications
Configural learning (CL) is a form of higher order associative learning wherein when snails experience two contrasting stimuli together such as predatory odour (crayfish effluent: predator of snails) and food odour (C: carrot odour) they learn and associate risk with food. This kind of learning involves a decision making as the two stimuli invoke opposite responses and animals need to decide for how long to avoid food as there exists an energy tradeoff. The memory for CL has been shown to last 3h. However, when snails are exposed to certain plant favonoids such as Green tea or Quercetin (found in several fruits and vegetables) the memory for CL is enhanced and now the snails avoid food for longer duration. This long-term memory might result due to effects of these plant favonoids on several molecular pathways that enhance memory formation. We found that one such molecule that is essential for long-term memory formation CREB (cyclic AMP response element binding protein) is upregulated by quercetin in the central nervous system of Lymnaea stagnalis.
Research article: Publications
To eat or not to eat: Garcia effect in snails
Taste aversion learning is universal across animal taxa. In animals a single presentation of a novel food substance followed hours later by visceral illness causes animals to avoid that taste. This is known as bait-shyness or the Garcia effect. Humans demonstrate this by avoiding a certain food following the development of nausea after ingesting that food (‘Sauce Bearnaise-effect’). Lymnaea stagnalis is capable of the Garcia effect. A single ‘pairing’ of a novel taste, a carrot slurry followed hours later by a heat shock stressor (HS) is sufficient to suppress feeding response elicited by carrot for at least 24h. The heat stress acts as a sickness inducing stimulus in this case similar to the nausea that we feel. Other food tastes are not suppressed but only the one that was novel and following which the HS stressor was applied. If snails had previously been exposed to carrot as their food source, the Garcia-like effect does not occur when carrot is ‘paired’ with the HS. The HS up-regulates two heat shock proteins (HSPs), HSP70 and HSP40 in the central nervous system of Lymnaea stagnalis and when the upregulation of HSPs are blocked we do not see the Garcia effect memory phenotype leading us to conclude that these proteins might be necessary for such associative learning and memory formation.
We have now performed multiple experiments showing different types of stimulus that can result in Garcia effect in snails and also ways to block this effect or enhance the memory for it.
Research article: Publications
Taste aversion learning is universal across animal taxa. In animals a single presentation of a novel food substance followed hours later by visceral illness causes animals to avoid that taste. This is known as bait-shyness or the Garcia effect. Humans demonstrate this by avoiding a certain food following the development of nausea after ingesting that food (‘Sauce Bearnaise-effect’). Lymnaea stagnalis is capable of the Garcia effect. A single ‘pairing’ of a novel taste, a carrot slurry followed hours later by a heat shock stressor (HS) is sufficient to suppress feeding response elicited by carrot for at least 24h. The heat stress acts as a sickness inducing stimulus in this case similar to the nausea that we feel. Other food tastes are not suppressed but only the one that was novel and following which the HS stressor was applied. If snails had previously been exposed to carrot as their food source, the Garcia-like effect does not occur when carrot is ‘paired’ with the HS. The HS up-regulates two heat shock proteins (HSPs), HSP70 and HSP40 in the central nervous system of Lymnaea stagnalis and when the upregulation of HSPs are blocked we do not see the Garcia effect memory phenotype leading us to conclude that these proteins might be necessary for such associative learning and memory formation.
We have now performed multiple experiments showing different types of stimulus that can result in Garcia effect in snails and also ways to block this effect or enhance the memory for it.
Research article: Publications
PAST RESEARCH
Dynamic colour change
We find a unique capability in some animals to change their body colour dynamically. Animals do so either for communication, camouflage or thermoregulation. I found that the Indian rock agama Psammophilus dorsalis also shows rapid change in body colour specific to the social context. The males turn orange dorsally and black laterally when courting females and the same body regions turn yellow and orange when fighting with other males. Although males show higher chromatic contrast (high colour contrast) when courting females, speed of the colour change is faster during competitive encounters with other males. The nature of this social colour communication also differed across populations in anthropogenically-disturbed landscapes. I found that compared to males from rural areas, suburban males were slower to change colour and showed duller and paler colours during staged social encounters. Thus we see that environmental disturbance along with affecting several other traits in various taxa can also affect the colour changing ability in animals and this study is the first one to show that.
Research article: Publication
We find a unique capability in some animals to change their body colour dynamically. Animals do so either for communication, camouflage or thermoregulation. I found that the Indian rock agama Psammophilus dorsalis also shows rapid change in body colour specific to the social context. The males turn orange dorsally and black laterally when courting females and the same body regions turn yellow and orange when fighting with other males. Although males show higher chromatic contrast (high colour contrast) when courting females, speed of the colour change is faster during competitive encounters with other males. The nature of this social colour communication also differed across populations in anthropogenically-disturbed landscapes. I found that compared to males from rural areas, suburban males were slower to change colour and showed duller and paler colours during staged social encounters. Thus we see that environmental disturbance along with affecting several other traits in various taxa can also affect the colour changing ability in animals and this study is the first one to show that.
Research article: Publication
Anti-predatory strategies
Animals are always faced with choices and they have to make decisions based on the costs and benefits of the situation. Escape decisions are such important economic decisions that animals have to make for their survival. Several external environmental factors and intrinsic traits of the organism are responsible for the escape strategy that we observe across different species and also within a species across different populations or sexes. I examined the effects of external environmental factors like living in an urban landscape versus wild rural habitat on escape strategies in the rock agama. I found that the urban lizards used lower perches and chose refuges that were closer to their perches compared to rural lizards. Flight initiation distance (FID) of urban lizards in the field was shorter than that of rural lizards. But whereas the differences in escape strategies were very prominent in the males, the females showed similar strategies across habitat. If you look closely at the photograph of the female you will understand that they mostly rely on crypsis to avoid predation and thus we find no difference across habitat. The urban lizards have short FIDs because living in an urbanised environment has habituated them to less or non-lethal human disturbances and thus they let humans approach much closer to them than the inexperienced rural lizards. Research article : Publications Larval anti-predatory learning Successful survival of a prey organism depends on their ability to detect predators and then avoid them by responding appropriately. I investigated the nature of predator detection in the larval bronzed frog and found that they have an innate mechanism to detect predator odour cues. Along their lifecycle as they mature and experience predation events or cues of predation events they also learn about their injured conspecific cues as a threat signal. Thus both innate and learnt mechanisms are involved in predator detection and avoidance in these tadpoles. I also wanted to test if they can learn about a novel cue as threat because this would then give them advantage to avoid exotic introduced predators. Very interesting, I found that they do learn about novel cues when it is paired with injured conspecific cues and this learning occurs as fast as in 5 days. Research article: Publications |
Laterality in colour and motion detection
It is well known in humans that our left half of the brain functions in logical and computational decisions and our right brain hemisphere is the creative and emotional side. But little was known that even lizards have partitioned their brains to do different tasks. Till date very few studies in reptiles have shown that there exists brain laterality i.e. independent functioning of the two brain hemispheres for different tasks. I used moving robotic lizard heads of different colours (as the lizard use colour for communication) and with different speeds (perform head bob during behavioural interactions) to show in the Indian rock agamas (picture on the right) that they responded to motion or movement when viewed from both left and right eyes but responded more to colour when viewed from their left eye. This signifies that their right brain hemisphere (left eye corresponds to neuronal connections to the right brain hemisphere) is more responsive to colours but motion is processed equally well in both hemispheres of the brain. This study add to our understanding of brain laterality in wild animals and helps to demonstrate that such brain functionality is conserved across various animal groups like birds, amphibians and other lizard groups which show similarity in right hemisphere dominance for social interaction.
Research article: Publications
It is well known in humans that our left half of the brain functions in logical and computational decisions and our right brain hemisphere is the creative and emotional side. But little was known that even lizards have partitioned their brains to do different tasks. Till date very few studies in reptiles have shown that there exists brain laterality i.e. independent functioning of the two brain hemispheres for different tasks. I used moving robotic lizard heads of different colours (as the lizard use colour for communication) and with different speeds (perform head bob during behavioural interactions) to show in the Indian rock agamas (picture on the right) that they responded to motion or movement when viewed from both left and right eyes but responded more to colour when viewed from their left eye. This signifies that their right brain hemisphere (left eye corresponds to neuronal connections to the right brain hemisphere) is more responsive to colours but motion is processed equally well in both hemispheres of the brain. This study add to our understanding of brain laterality in wild animals and helps to demonstrate that such brain functionality is conserved across various animal groups like birds, amphibians and other lizard groups which show similarity in right hemisphere dominance for social interaction.
Research article: Publications
Physiological coping styles:
Graphical abstract of my new paper on social coping styles of lizards across urban and rural habitats.
Research article: Publications
Graphical abstract of my new paper on social coping styles of lizards across urban and rural habitats.
Research article: Publications
Learning Strategies:
Animals need to learn about novel food, shelter, predators to survive in this ever changing world. The rock agamas are residents of both urban habitats as well as wild rural habitats and the two places are drastically different in the structural complexity and dynamicity. Urban environments keep shifting during the lifetime of these lizards and exposes them to novel and dynamic challenges. The lizards need to select safe places to hide and bask. I found that the urban lizards were faster to learn about safe refuges when attacked while rural lizards were slower. Even when we switched the contigency of safety i.e. the previous "safe" place suddenly became "unsafe" now, the urban lizards quickly switched their learning (reversal learning) and were faster than rural lizards to learn about this new "safe" place. To know more about the learning skills in these lizards please read research article in my publication page.
Research Article: Publications
Animals need to learn about novel food, shelter, predators to survive in this ever changing world. The rock agamas are residents of both urban habitats as well as wild rural habitats and the two places are drastically different in the structural complexity and dynamicity. Urban environments keep shifting during the lifetime of these lizards and exposes them to novel and dynamic challenges. The lizards need to select safe places to hide and bask. I found that the urban lizards were faster to learn about safe refuges when attacked while rural lizards were slower. Even when we switched the contigency of safety i.e. the previous "safe" place suddenly became "unsafe" now, the urban lizards quickly switched their learning (reversal learning) and were faster than rural lizards to learn about this new "safe" place. To know more about the learning skills in these lizards please read research article in my publication page.
Research Article: Publications