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1.
Healthcare (Basel) ; 12(11)2024 May 24.
Article En | MEDLINE | ID: mdl-38891146

BACKGROUND: Music Therapy (MT) is a non-pharmacological, art-based intervention that employs music experiences within a therapeutic alliance to attend to clients' physical, emotional, cognitive, and social requirements. This is the first study aiming at investigating the impact of MT on the psychological facets of children suffering from cancer. METHODS: The study, combining the AQR and m-YPAS assessment tools, evaluated behavioral, sound-musical, and interactive parameters in pediatric oncology patients undergoing MT sessions during hospitalization. Fifty patients admitted to the Paediatric Oncology and Haematology Unit at Policlinico S. Orsola Hospital in Bologna, Italy, were enrolled, irrespective of their treatment regimen. Data collection occurred on the first day of the MT session between 3 p.m. and 5 p.m., with observations conducted by independent observers. In addition to traditional statistical analysis, network analysis was used to explore the combined interactions of all parameters, effectively discerning the distinctive roles played by each one during therapy sessions and their influence on all others. RESULTS: Network analysis highlighted distinct patterns of interactions among parameters during the various sessions, emphasizing the role of positive emotions and a calm setting, the child's ability to take the initiative in sessions, their sense of agency, and the parent's role in guiding them. Significant differences were recorded at each time point between all variables considered. CONCLUSIONS: The results of this innovative study may pave the way for future multicenter studies aimed at further exploring the role of MT in children undergoing both curative and palliative treatments for cancer.

2.
J Exp Biol ; 227(8)2024 Apr 15.
Article En | MEDLINE | ID: mdl-38639079

Animals, including humans, learn and remember to avoid a novel food when its ingestion is followed, hours later, by sickness - a phenomenon initially identified during World War II as a potential means of pest control. In the 1960s, John Garcia (for whom the effect is now named) demonstrated that this form of conditioned taste aversion had broader implications, showing that it is a rapid but long-lasting taste-specific food aversion with a fundamental role in the evolution of behaviour. From the mid-1970s onward, the principles of the Garcia effect were translated to humans, showing its role in different clinical conditions (e.g. side-effects linked to chemotherapy). However, in the last two decades, the number of studies on the Garcia effect has undergone a considerable decline. Since its discovery in rodents, this form of learning was thought to be exclusive to mammals; however, we recently provided the first demonstration that a Garcia effect can be formed in an invertebrate model organism, the pond snail Lymnaea stagnalis. Thus, in this Commentary, after reviewing the experiments that led to the first characterization of the Garcia effect in rodents, we describe the recent evidence for the Garcia effect in L. stagnalis, which may pave the way for future studies in other invertebrates and mammals. This article aims to inspire future translational and ecological studies that characterize the conserved mechanisms underlying this form of learning with deep evolutionary roots, which can be used to address a range of different biological questions.


Conditioning, Classical , Taste , Animals , Humans , Lymnaea , Snails , Mammals
3.
Article En | MEDLINE | ID: mdl-37395798

The pond snail Lymnaea stagnalis exhibits various forms of associative learning including (1) operant conditioning of aerial respiration where snails are trained not to open their pneumostome in a hypoxic pond water environment using a weak tactile stimulus to their pneumostome as they attempt to open it; and (2) a 24 h-lasting taste-specific learned avoidance known as the Garcia effect utilizing a lipopolysaccharide (LPS) injection just after snails eat a novel food substance (carrot). Typically, lab-inbred snails require two 0.5 h training sessions to form long-term memory (LTM) for operant conditioning of aerial respiration. However, some stressors (e.g., heat shock or predator scent) act as memory enhancers and thus a single 0.5 h training session is sufficient to enhance LTM formation lasting at least 24 h. Here, we found that snails forming a food-aversion LTM following Garcia-effect training exhibited enhanced LTM following operant condition of aerial respiration if trained in the presence of the food substance (carrot) they became averse to. Control experiments led us to conclude that carrot becomes a 'sickness' risk signal and acts as a stressor, sufficient to enhance LTM formation for another conditioning procedure.


Lymnaea , Memory, Long-Term , Animals , Lymnaea/physiology , Learning , Snails , Conditioning, Operant/physiology
4.
Article En | MEDLINE | ID: mdl-38013046

A novel food followed by sickness, causes a taste-specific conditioned aversion, known as the 'Garcia effect'. We recently found that both a heat shock stressor (30 °C for 1 h - HS) and the bacterial lipopolysaccharide (LPS) can be used as 'sickness-inducing' stimuli to induce a Garcia effect in the pond snail Lymnaea stagnalis. Additionally, if snails are exposed to acetylsalicylic acid (ASA) present in aspirin tablets before the LPS injection, the formation of the Garcia effect is prevented. Here, we hypothesized that exposing snails to crushed aspirin before the HS (ASA-HS) would prevent the HS-induced 'sickness state' and - therefore -the Garcia effect. Unexpectantly, the ASA-HS procedure induced a generalized and long-lasting feeding suppression. We thus investigate the molecular effects underlying this phenomenon. While the exposure to the HS alone resulted in a significant upregulation of the mRNA levels of the Heat Shock Protein 70 (HSP 70) in snails' central ring ganglia, the ASA-HS procedure induced an even greater upregulation of HSP70, suggesting that the ASA-HS combination causes a severe stress response that inhibits feeding. Additionally, we found that the ASA-HS procedure induced a significant downregulation of the mRNA levels of genes involved with the serotoninergic system which regulates feeding in snails. Finally, the ASA-HS procedure prevented HS-induced upregulation of the mRNA levels of key neuroplasticity genes. Our study indicates that two sickness-inducing stimuli can have different physiological responses even if behavioral outcomes are similar under some learning contexts.


Aspirin , Lipopolysaccharides , Animals , Aspirin/pharmacology , Lipopolysaccharides/pharmacology , Heat-Shock Response , HSP70 Heat-Shock Proteins/genetics , RNA, Messenger , Lymnaea/genetics
6.
Biol Bull ; 244(2): 115-127, 2023 04.
Article En | MEDLINE | ID: mdl-37725701

AbstractThe pond snail Lymnaea stagnalis employs aerial respiration under hypoxia and can be operantly conditioned to reduce this behavior. When applied individually, a heat shock (30 °C for 1 h) and the flavonoid quercetin enhance long-term memory formation for the operant conditioning of aerial respiration. However, when snails are exposed to quercetin before the heat shock, long-term memory is no longer enhanced. This is because quercetin prevents the heat-induced upregulation of heat-shock proteins 70 and 40. When we tested the memory outcome of operant conditioning due to the simultaneous exposure to quercetin and 30 °C, we found that Lymnaea entered a quiescent survival state. The same behavioral response occurred when snails were simultaneously exposed to quercetin and pond water made hypoxic by bubbling nitrogen through it. Thus, in this study, we performed six experiments to propose a physiological explanation for that curious behavioral response. Our results suggest that bubbling nitrogen in pond water, heating pond water to 30 °C, and bubbling nitrogen in 30 °C pond water create a hypoxic environment, to which organisms may respond by upregulating the heat-shock protein system. On the other hand, when snails experience quercetin together with these hypoxic conditions, they can no longer express the physiological stress response evoked by heat or hypoxia. Thus, the quiescent survival state could be an emergency response to survive the hypoxic condition when the heat-shock proteins cannot be activated.


Lymnaea , Quercetin , Animals , Quercetin/pharmacology , Hypoxia , Nitrogen , Water
7.
Biology (Basel) ; 12(8)2023 Aug 07.
Article En | MEDLINE | ID: mdl-37626986

Lymnaea stagnalis learns and remembers to avoid certain foods when their ingestion is followed by sickness. This rapid, taste-specific, and long-lasting aversion-known as the Garcia effect-can be formed by exposing snails to a novel taste and 1 h later injecting them with lipopolysaccharide (LPS). However, the exposure of snails to acetylsalicylic acid (ASA) for 1 h before the LPS injection, prevents both the LPS-induced sickness state and the Garcia effect. Here, we investigated novel aspects of this unique form of conditioned taste aversion and its pharmacological regulation. We first explored the transcriptional effects in the snails' central nervous system induced by the injection with LPS (25 mg), the exposure to ASA (900 nM), as well as their combined presentation in untrained snails. Then, we investigated the behavioral and molecular mechanisms underlying the LPS-induced Garcia effect and its pharmacological regulation by ASA. LPS injection, both alone and during the Garcia effect procedure, upregulated the expression levels of immune- and stress-related targets. This upregulation was prevented by pre-exposure to ASA. While LPS alone did not affect the expression levels of neuroplasticity genes, its combination with the conditioning procedure resulted in their significant upregulation and memory formation for the Garcia effect.

8.
Children (Basel) ; 10(7)2023 Jul 13.
Article En | MEDLINE | ID: mdl-37508714

The incidence and collective impact of early adverse experiences, trauma, and pain continue to increase. This underscores the urgent need for translational efforts between clinical and preclinical research to better understand the underlying mechanisms and develop effective therapeutic approaches. As our understanding of these issues improves from studies in children and adolescents, we can create more precise preclinical models and ultimately translate our findings back to clinical practice. A multidisciplinary approach is essential for addressing the complex and wide-ranging effects of these experiences on individuals and society. This narrative review aims to (1) define pain and trauma experiences in childhood and adolescents, (2) discuss the relationship between pain and trauma, (3) consider the role of biological memory, (4) decipher the relationship between pain and trauma using preclinical data, and (5) examine the role of the environment by introducing the importance of epigenetic processes. The ultimate scope is to better understand the wide-ranging effects of trauma, abuse, and chronic pain on children and adolescents, how they occur, and how to prevent or mitigate their effects and develop effective treatment strategies that address both the underlying causes and the associated physiological and psychological effects.

9.
Cancers (Basel) ; 15(13)2023 Jul 04.
Article En | MEDLINE | ID: mdl-37444606

BACKGROUND: Pediatric cancer presents mental and physical challenges for patients and their caregivers. However, parental distress has been understudied despite its negative impact on quality of life, disability, and somatic disorders. Parents of oncopediatric patients experience high levels of suffering with their resilience tested throughout their children's illness. Identifying at-risk parents and offering specific treatments is crucial and urgent to prevent or alleviate negative outcomes. METHODS: This study used statistical and network analyses to examine symptom patterns assessed by the Kellner Symptom Questionnaire in 16 fathers and 23 mothers at different time points: diagnosis, treatment, and discharge. RESULTS: The results indicated significantly higher distress levels in parents of oncopediatric children compared to the control reference population. Gender-specific differences in symptom profiles were observed at each time point, and symptoms showed a gradual but non-significant decrease over time. CONCLUSIONS: The network analysis yielded valuable insights that, when applied in clinical practice, can guide the implementation of timely treatments to prevent and manage parental distress, thus addressing long-term, stress-related issues in primary caregivers of children diagnosed and treated for cancer.

10.
Neurobiol Learn Mem ; 203: 107775, 2023 09.
Article En | MEDLINE | ID: mdl-37263390

Predator detection induces both behavioral and physiological responses in prey organisms. Our model organism, the pond snail Lymnaea stagnalis, shows multiple defensive behaviors in response to predator cues. In this study, we investigated and compared the transcriptional effects induced by the exposure to a predator scent (i.e., crayfish effluent - CE) in a strain of lab-inbred snails (i.e., W snails), which have been raised and maintained under standardized laboratory conditions for generations and a strain of freshly collected snails (i.e., Margo snails), which live in a crayfish-free pond. Neither the W- strain nor the Margo Lake snails used in this study have actually experienced crayfish. However, the W strain innately recognizes crayfish as a threat. We found that, following the exposure to CE, both strains showed significantly higher mRNA levels of serotonin-related genes. This is important, as the serotonergic system modulates predator detection and vigilance behaviors in pond snails. However, the expression levels of CREB1 and HSP70 were only upregulated in CE-exposed W snails but not in Margo ones. As CREB1 plays a key role in learning and memory formation, whereas HSP70 is involved in stress response, we investigated whether these differences in CREB1 and HSP70 mRNA levels would reflect differences in predator-induced learning (e.g., configural learning). We found that only W snails formed configural learning memory, whereas Margo snails did not. Thus, while both the strains molecularly respond to the CE by upregulating the serotoninergic system, only W snails behaviorally recognize CE as a threat and, therefore, form configural learning.


Learning , Predatory Behavior , Animals , Predatory Behavior/physiology , Odorants , Serotonin/metabolism , Lymnaea
11.
J Exp Biol ; 226(10)2023 05 15.
Article En | MEDLINE | ID: mdl-37232484

Nutritional status plays an important role in cognitive functioning, but there is disagreement on the role that food deprivation plays in learning and memory. In this study, we investigated the behavioral and transcriptional effects induced by different lengths of food deprivation: 1 day, which is a short time period of food deprivation, and 3 days, which is an 'intermediate' level of food deprivation. Snails were subjected to different feeding regimens and then trained for operant conditioning of aerial respiration, where they received a single 0.5 h training session followed by a long-term memory (LTM) test 24 h later. Immediately after the memory test, snails were killed and the expression levels of key genes for neuroplasticity, energy balance and stress response were measured in the central ring ganglia. We found that 1 day of food deprivation was not sufficient to enhance snails' LTM formation and subsequently did not result in any significant transcriptional effects. However, 3 days of food deprivation resulted in enhanced LTM formation and caused the upregulation of neuroplasticity and stress-related genes and the downregulation of serotonin-related genes. These data provide further insight into how nutritional status and related molecular mechanisms impact cognitive function.


Learning , Lymnaea , Animals , Lymnaea/physiology , Memory, Long-Term/physiology , Conditioning, Operant/physiology , Food Deprivation/physiology
12.
Int J Mol Sci ; 24(10)2023 May 12.
Article En | MEDLINE | ID: mdl-37240042

Cognitive impairment in schizophrenia remains a clinically and pharmacologically unsolved challenge. Clinical and preclinical studies have revealed that the concomitant reduction in dysbindin (DYS) and dopamine receptor D3 functionality improves cognitive functions. However, the molecular machinery underlying this epistatic interaction has not yet been fully elucidated. The glutamate NMDA receptors and the neurotrophin BDNF, with their established role in promoting neuroplasticity, may be involved in the complex network regulated by the D3/DYS interaction. Furthermore, as inflammation is involved in the etiopathogenesis of several psychiatric diseases, including schizophrenia, the D3/DYS interaction may affect the expression levels of pro-inflammatory cytokines. Thus, by employing mutant mice bearing selective heterozygosis for D3 and/or DYS, we provide new insights into the functional interactions (single and synergic) between these schizophrenia susceptibility genes and the expression levels of key genes for neuroplasticity and neuroinflammation in three key brain areas for schizophrenia: the prefrontal cortex, striatum, and hippocampus. In the hippocampus, the epistatic interaction between D3 and DYS reversed to the wild-type level the downregulated mRNA levels of GRIN1 and GRIN2A were observed in DYS +/- and D3 +/- mice. In all the areas investigated, double mutant mice had higher BDNF levels compared to their single heterozygote counterparts, whereas D3 hypofunction resulted in higher pro-inflammatory cytokines. These results may help to clarify the genetic mechanisms and functional interactions involved in the etiology and development of schizophrenia.


Brain-Derived Neurotrophic Factor , Receptors, Dopamine D3 , Mice , Animals , Receptors, Dopamine D3/genetics , Receptors, Dopamine D3/metabolism , Dysbindin/metabolism , Brain-Derived Neurotrophic Factor/genetics , Brain-Derived Neurotrophic Factor/metabolism , Neuroinflammatory Diseases , Brain/metabolism , Neuronal Plasticity/genetics
13.
Physiol Behav ; 263: 114137, 2023 05 01.
Article En | MEDLINE | ID: mdl-36841323

Food is not only necessary for our survival but also elicits pleasure. However, when a novel food is followed sometime later by nausea or sickness animals form a long-lasting association to avoid that food. This phenomenon is called the 'Garcia effect'. We hypothesized that lipopolysaccharide (LPS) could be used as the sickness-inducing stimulus to produce a Garcia-like effect in inbred and wild populations of Lymnaea stagnalis. We first demonstrated that the injection of 25 µg (6.25 µg/mL) of Escherichia coli-derived LPS serotype O127:B8 did not by itself alter snails' feeding behavior. Then we showed that the presentation of a novel appetitive stimulus (i.e., carrot slurry) and LPS resulted in a taste-specific and long-lasting feeding suppression (i.e., the Garcia-like effect). We also found strain-specific variations in the duration of the long-term memory (LTM). That is, while the LTM for the Garcia-like effect in W-strain snails persisted for 24h, LTM persisted for 48h in freshly collected Margo snails and their F1 offspring. Finally, we demonstrated that the exposure to a non-steroidal anti-inflammatory drug, aspirin (acetylsalicylic acid) before the LPS injection prevented both the LPS-induced sickness state and the Garcia-like effect from occurring. The results of this study may pave the way for new research that aims at (1) uncovering the conserved molecular mechanisms underlying the Garcia-like effect, (2) understanding how cognitive traits vary within and between species, and (3) creating a holistic picture of the complex dialogue between the immune and central nervous systems.


Lipopolysaccharides , Memory , Animals , Lipopolysaccharides/pharmacology , Lymnaea/physiology , Taste/physiology , Memory, Long-Term , Conditioning, Operant
14.
J Exp Biol ; 226(3)2023 02 01.
Article En | MEDLINE | ID: mdl-36719249

In this Commentary, we shed light on the use of invertebrates as model organisms for understanding the causal and conserved mechanisms of learning and memory. We provide a condensed chronicle of the contribution offered by mollusks to the studies on how and where the nervous system encodes and stores memory and describe the rich cognitive capabilities of some insect species, including attention and concept learning. We also discuss the use of planarians for investigating the dynamics of memory during brain regeneration and highlight the role of stressful stimuli in forming memories. Furthermore, we focus on the increasing evidence that invertebrates display some forms of emotions, which provides new opportunities for unveiling the neural and molecular mechanisms underlying the complex interaction between stress, emotions and cognition. In doing so, we highlight experimental challenges and suggest future directions that we expect the field to take in the coming years, particularly regarding what we, as humans, need to know for preventing and/or delaying memory loss. This article has an associated ECR Spotlight interview with Veronica Rivi.


Invertebrates , Learning , Animals , Humans , Invertebrates/physiology , Cognition/physiology , Brain/physiology , Emotions/physiology
15.
Brain Behav Immun ; 107: 385-396, 2023 01.
Article En | MEDLINE | ID: mdl-36400332

Mounting evidence suggests a link between gut microbiota abnormalities and post-traumatic stress disorder (PTSD). However, whether and how the gut microbiota influences PTSD susceptibility is poorly understood. Here using the arousal-based individual screening model, we provide evidence for pre-trauma and post-trauma gut microbiota alterations in susceptible mice exhibiting persistent PTSD-related phenotypes. A more in-depth analysis revealed an increased abundance of bacteria affecting brain processes including myelination, and brain systems like the dopaminergic neurotransmission. Because dopaminergic dysfunctions play a key role in the pathophysiological mechanisms subserving PTSD, we assessed whether these alterations in gut microbiota composition could be associated with abnormal levels of metabolites inducing dopaminergic dysfunctions. We found high levels of the l-tyrosine-derived metabolite p-cresol exclusively in the prefrontal cortex of susceptible mice. We further uncovered abnormal levels of dopamine and DOPAC, together with a detrimental increase of dopamine D3 receptor expression, exclusively in the prefrontal cortex of susceptible mice. Conversely, we observed either resilience mechanisms aimed at counteracting these p-cresol-induced dopaminergic dysfunctions or myelination-related resilience mechanisms only in the prefrontal cortex of resilient mice. These findings reveal that gut microbiota abnormalities foster trauma susceptibility and thus it may represent a promising target for therapeutic interventions.


Dopamine , Mice , Animals
16.
Neuroendocrinology ; 113(4): 406-422, 2023.
Article En | MEDLINE | ID: mdl-36223719

INTRODUCTION: The Garcia effect, a solid learning paradigm, was used to investigate the molecular and behavioral effects induced by different lengths of fasting on the cognitive functions in the pond snail Lymnaea stagnalis, a valid model system. METHODS: Three experimental groups were used: moderately hungry snails, food-deprived for 1 day (D1 snails), severely hungry snails (D5 snails), fasting for 5 days, and satiated snails with ad libitum access to food (AL snails). In the Garcia effect, a single pairing of an appetitive stimulus with a heat stressor results in a learned taste-specific negative hedonic shift. D5 snails were injected with bovine insulin and D1 snails with the insulin receptor antibody (Ab). As a control group, AL snails were injected with saline. Gene expression analyses were performed by real-time PCR in snails' central nervous system (CNS). RESULTS: AL snails are "average learners," D1 snails are the best performers, whereas the D5 ones do not show the Garcia effect. Severely fasting snails injected with insulin 3 h before the training procedure show the Garcia effect, whereas injecting 1-day fasting snails with insulin receptor Ab blocks their ability to express memory. The differences in memory performances are associated with changes in the expression levels of selected targets involved in neuronal plasticity, energy homeostasis, and stress response. DISCUSSION: Our results suggest that short-term fasting creates an optimal internal state in L. stagnalis' CNS, allowing a spike in insulin release and an upregulation of genes involved in neuroplasticity. Long-term fasting, instead, upregulates genes involved in energy homeostasis and animal survival.


Lymnaea , Taste , Animals , Cattle , Lymnaea/physiology , Taste/physiology , Receptor, Insulin/genetics , Receptor, Insulin/pharmacology , Avoidance Learning/physiology , Insulin/pharmacology , Fasting , Cognition
17.
Children (Basel) ; 9(12)2022 Nov 30.
Article En | MEDLINE | ID: mdl-36553324

Severe acute behavioral and emotional problems represent one of the most serious treatment-related adverse effects for children and adolescents who have cancer. The critical and severe nature of these symptoms often makes necessary the use of psychotropic drugs. A working group composed of experts in multiple disciplines had the task of creating an agreement regarding a management plan for severe acute behavioral and emotional problems (SABEPs) in children and adolescents treated for cancer. To obtain global information on the use of psychotropic drugs in pediatric oncology, the working group first developed and mailed a 15-item questionnaire to many Italian pediatric oncology centers. Overall, an evident lack of knowledge and education regarding the use of psychotropic medications for the treatment of SABEPs was found. Thus, by referring to an adapted version of the Delphi method of consensus and standard methods for the elaboration of clinical questions (PICOs), the working group elaborated evidence-based recommendations for psychotropic drugs in the pediatric oncology setting. Furthermore, based on a thorough multivariate analysis of needs and difficulties, a comprehensive management flow was developed to optimize therapeutic interventions, which allows more accurate and efficient matching of the acute needs of patients while guiding treatment options.

18.
Naunyn Schmiedebergs Arch Pharmacol ; 395(12): 1573-1585, 2022 12.
Article En | MEDLINE | ID: mdl-36100758

By employing a reductionistic (but not simplistic) approach using an established invertebrate model system, the pond snail Lymnaea stagnalis, we investigated whether (1) lipopolysaccharide (LPS)-induced inflammation would cause a sickness state and impair cognitive function, and-if so-(2) would aspirin (acetylsalicylic acid-ASA) restore the impaired cognition. To test our hypotheses, we first determined if the injection of 25 mg (6.25 µg/mL) of Escherichia coli-derived LPS serotype O127:B8 altered homeostatic behavior, aerial respiration, and then determined if LPS altered memory formation when this behavior was operantly conditioned. Next, we determined if ASA altered the LPS-induced changes in both aerial respiration and cognitive functions. LPS induced a sickness state that increased aerial respiration and altered the ability of snails to form or recall long-term memory. ASA reverted the LPS-induced sickness state and thus allowed long-term memory both to be formed and recalled. We confirmed our hypotheses and provided the first evidence in an invertebrate model system that an injection of LPS results in a sickness state that obstructs learning and memory, and this impairment can be prevented by a non-steroidal anti-inflammatory.


Lipopolysaccharides , Memory , Animals , Lipopolysaccharides/toxicity , Conditioning, Operant , Aspirin/pharmacology , Lymnaea , Memory Disorders/chemically induced , Memory Disorders/drug therapy
19.
Biol Bull ; 243(1): 38-43, 2022 08.
Article En | MEDLINE | ID: mdl-36108033

AbstractAcute extreme heat events are increasing in frequency and intensity. Understanding their effects on ectothermic organisms' homeostasis is both important and urgent. In this study we found that the exposure to an acute heat shock (30 °C for 1 hour) repeated for a seven-day period severely suppressed the feeding behavior of laboratory-inbred (W-strain) Lymnaea stagnalis, whereas the first-generation offspring of freshly collected wild (F1 D-strain) snails raised and maintained under similar laboratory conditions did not show any alterations. The W-strain snails might have inadvertently been selected against heat tolerance since they were first brought into the laboratory many (∼70) years ago. We also posit that the F1 D-strain snails do not perceive the heat shock as a sufficient stressor to alter their feeding response because their parental populations in wild environments have repeatedly experienced temperature fluctuations, thus becoming more tolerant and resilient to heat. The different responses exhibited by two strains of the same species highlight the importance of selecting the most appropriate strain for addressing questions about the impacts of global warming on organisms' physiology and behavior.


Conditioning, Operant , Lymnaea , Animals , Lymnaea/physiology
20.
Neurotoxicology ; 92: 61-66, 2022 09.
Article En | MEDLINE | ID: mdl-35907516

Fluoride (F-), has been found to affect learning and memory in several species. In this study, we exposed an F--naïve, inbred strain of Lymnaea stagnalis to a concentration of F- similar to that naturally occurring in wild ponds. We found that the exposure to F- before the configural learning procedure obstructs the memory formation and blocks the configural learning-induced upregulation of CREB1, GRIN1, and HSP70 in snails' central ring ganglia. Along with altering the mRNA levels of these key genes for memory formation, a single acute F- exposure also upregulates Cytochrome c Oxidase, a major regulatory enzyme of the electron transport chain, which plays direct or indirect roles in reactive oxygen species production. As the central nervous system is sensitive to oxidative stress and consistent with previous studies from mammals, our results suggest a potential role of oxidative stress in memory impairment. To our knowledge, this is the first study investigating the neuronal mechanism of memory impairment in an invertebrate species that is exposed to natural F- levels.


Fluorides , Lymnaea , Animals , Central Nervous System , Electron Transport Complex IV , Fluorides/toxicity , Lymnaea/physiology , Mammals , Memory, Long-Term/physiology , RNA, Messenger , Reactive Oxygen Species
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