Periodic Reporting for period 1 - GEMiNI (A genetic model for neurorehabilitation)
Período documentado: 2018-04-01 hasta 2020-03-31
My long-term objective is to establish the fruit fly Drosophila as a genetic model for neurorehabilitation and recovery after amputation, which will allow the identification of new genes and mechanisms of motor plasticity. In order to carry out these aims, I will take advantage of the sophisticated Drosophila neurogenetic toolkit that allows gene manipulation and the execution of in vivo gain and loss-of-function experiments in a controlled number of neurons. In addition, I will use an adult fly walking assay, the FlyWalker system, which allows a detailed quantification of locomotor activity.
Our results show that recovery is a conserved process across species and that age has a deterring effect on this process with older animals lacking the ability to adapt.
We also show that genes involved in neuronal plasticity typically associated to olfactory associative memory control the process of recovery.
This work will have a significant impact on how we understand motor recovery and will open new venues to promote recovery in motor dysfunction.
Our results show that recovery is a conserved process across species and that age has a deterring effect on this process with older animals lacking the ability to adapt.
We also show that genes involved in neuronal plasticity typically associated to olfactory associative memory control the process of recovery.
This work will have a significant impact on how we understand motor recovery and will open new venues to promote recovery in motor dysfunction.
In order to better understand locomotor recovery in Drosophila melanogaster, and to test our hypothesis that the aforementioned genes pertaining to the cAMP “memory cascade” play a role in locomotor adaptation, we examined the influence of several genes on motor recovery by observing how their loss of function mutants react and adapt to middle-leg amputation, while taking into account the established notion of wild type locomotor recovery. This was carried out using the FlyWalker system in order to study the kinematic adaptations, which occur after amputation in Canton-S (wild type) Drosophila melanogaster flies. We focused on the spatial parameters as these better reflect the kinematic improvements observed during neurorehabilitation.
Our data showed for the first time that Drosophila can recover from an injury and most strikingly, that the same genes that control olfactory associative learning also control motor learning, which per se will have a strong impact in the scientific community. Accordingly, we included additional aims in this project.
After the positive results of locomotor adaptation that occur post middle-leg amputation in various Drosophila melanogaster wild type lines including Canton-S, we sought to test if this phenotype was reproducible in the evolutionarily distant Drosophila species Drosophila pseudoobscura and Drosophila repleta. With this experiment, we aimed to understand whether there is any evolutionary conservation of our behavioral readout, which, in case of a positive result, adds robustness of our genetic model for neurorehabilitation.
Overall, the data regarding amputated walking behavior on Drosophila pseudoobscura and repleta strongly suggest that these, like their Canton-S Drosophila melanogaster counterpart, can efficiently deal with the amputation of both middle legs, doing so by adapting various locomotor parameters which grants them the ability to walk using only four legs.
Another physiological factor that seems affect the motor recovery is the aging. Results suggested that with aging the long-term memory is affected, whilst the short-memory is maintained. Our results demonstrated the effect of normal senescence in the normal walking pattern. Accordingly, it was verified the kinematic changes caused by the aging, such as the reduction of average speed. The most important evidence retired from these quantifications was the huge similarity between 1 and 7-weeks-old flies, suggesting that the level of learning acquired in 1-weeks-old flies is equivalent to the level of unlearning in 7-weeks-old flies.
In all age stages, the amputation procedure induced an immediate decrease of locomotor activity, as well as decrease of the instantaneous speed. Thus, it’s clearly that flies can readjust their motor representation in order to adapt to new biomechanical challenge.
Here I describe a novel approach to unravel an old and important question in the field of neuroscience, a strong case should be presented for publication in a high impact journal (currently under preparation). The acquired data indeed support the initial hypothesis of this project. Thus, the impact becomes reinforced since the initial hypothesis became fully supported. Finally, none of the current results precludes the executions of the initial aims, quite the opposite; it reinforces the validity and interest of those aims, which will be carried out in the short-term.
During the period of my MSCA I have participated in several dissemination activities. These included scientific meetings with my peers and with the general public. Equally important was my interaction with undergraduate medical students and master students from our institute, where I shared my results and scientific interest but also I fostered critical thinking and the importance of scientific research to solve the most complex biomedical questions facing our society.
Our data showed for the first time that Drosophila can recover from an injury and most strikingly, that the same genes that control olfactory associative learning also control motor learning, which per se will have a strong impact in the scientific community. Accordingly, we included additional aims in this project.
After the positive results of locomotor adaptation that occur post middle-leg amputation in various Drosophila melanogaster wild type lines including Canton-S, we sought to test if this phenotype was reproducible in the evolutionarily distant Drosophila species Drosophila pseudoobscura and Drosophila repleta. With this experiment, we aimed to understand whether there is any evolutionary conservation of our behavioral readout, which, in case of a positive result, adds robustness of our genetic model for neurorehabilitation.
Overall, the data regarding amputated walking behavior on Drosophila pseudoobscura and repleta strongly suggest that these, like their Canton-S Drosophila melanogaster counterpart, can efficiently deal with the amputation of both middle legs, doing so by adapting various locomotor parameters which grants them the ability to walk using only four legs.
Another physiological factor that seems affect the motor recovery is the aging. Results suggested that with aging the long-term memory is affected, whilst the short-memory is maintained. Our results demonstrated the effect of normal senescence in the normal walking pattern. Accordingly, it was verified the kinematic changes caused by the aging, such as the reduction of average speed. The most important evidence retired from these quantifications was the huge similarity between 1 and 7-weeks-old flies, suggesting that the level of learning acquired in 1-weeks-old flies is equivalent to the level of unlearning in 7-weeks-old flies.
In all age stages, the amputation procedure induced an immediate decrease of locomotor activity, as well as decrease of the instantaneous speed. Thus, it’s clearly that flies can readjust their motor representation in order to adapt to new biomechanical challenge.
Here I describe a novel approach to unravel an old and important question in the field of neuroscience, a strong case should be presented for publication in a high impact journal (currently under preparation). The acquired data indeed support the initial hypothesis of this project. Thus, the impact becomes reinforced since the initial hypothesis became fully supported. Finally, none of the current results precludes the executions of the initial aims, quite the opposite; it reinforces the validity and interest of those aims, which will be carried out in the short-term.
During the period of my MSCA I have participated in several dissemination activities. These included scientific meetings with my peers and with the general public. Equally important was my interaction with undergraduate medical students and master students from our institute, where I shared my results and scientific interest but also I fostered critical thinking and the importance of scientific research to solve the most complex biomedical questions facing our society.
Based on the aforementioned data, we hypothesize that several genes relevant for learning and memory play a role in the observed locomotor recovery phenotype. By descending on the pathway we went on affecting less of the memory phases required for consolidated memory, theoretically increasing the chance of memory acquisition as less molecular players were affected. These results show that all these mutants seem to play a role in locomotor adaptation and that LTM alone is not sufficient to promote the recovery phenotype.
Despite large investments in the field of neurorehabilitation and some improved methodologies, recovery outcomes are nevertheless variable amongst individuals that suffer from incapacitating motor conditions. Currently, the contribution of different brain structures responsible for the recovery process is only partially understood and, importantly, the role of specific genes remains mostly elusive. The elusiveness of a known genetic program at play during neurohabilitation is largely due to the absence of an appropriate genetic model to study this process and facilitate the design of approaches to identify new genes and mechanisms required for motor plasticity. This important question is still present and our work is currently filling this gap. Currently, and to my knowledge, no report has been published that insects can recover from incapacitating injuries (like more complex organisms such as mammals), and more importantly, that the same genes that control associative learning strikingly also control motor learning as a consequence of an injury.
Despite large investments in the field of neurorehabilitation and some improved methodologies, recovery outcomes are nevertheless variable amongst individuals that suffer from incapacitating motor conditions. Currently, the contribution of different brain structures responsible for the recovery process is only partially understood and, importantly, the role of specific genes remains mostly elusive. The elusiveness of a known genetic program at play during neurohabilitation is largely due to the absence of an appropriate genetic model to study this process and facilitate the design of approaches to identify new genes and mechanisms required for motor plasticity. This important question is still present and our work is currently filling this gap. Currently, and to my knowledge, no report has been published that insects can recover from incapacitating injuries (like more complex organisms such as mammals), and more importantly, that the same genes that control associative learning strikingly also control motor learning as a consequence of an injury.