Methods, systems, and devices for an invertebrate model of traumatic brain injury
Described herein are methods, systems, and devices for identifying agents and genetic pathways that modulate the effects of traumatic brain injury (TBI) in invertebrate model systems having a brain, e.g., Drosophila or C. elegans.
1. A method for assaying a test agent in Drosophila , the method comprising the steps of:
(i) delivering to one or more Drosophila individuals an impact to induce closed-head traumatic brain injury (TBI) wherein the step of delivering the impact comprises the steps of:
(a) providing the one or more unrestrained Drosophila individuals inside one or more walled containers secured to a spring-loaded acceleration assembly having first and second ends and defining a deflectable long axis therebetween, the assembly fixedly secured at the first end to a base, the one or more containers secured to the assembly at the second end, the assembly configured to accelerate the one or more secured walled containers toward a strike surface upon deflection of the assembly on the long axis followed by release; and
(b) deflecting the assembly on the long axis and releasing the deflected assembly, thereby accelerating the one or more secured walled containers toward and into contact with the strike surface, whereby the unrestrained Drosophila individuals in the one or more walled containers impact the one or more walled containers;
(ii) dosing the one or more Drosophila individuals with a test agent before or after the impact; and
(iii) after the impact, assessing in the dosed one or more Drosophila individuals the severity of a phenotype associated with closed-head TBI selected from the group consisting of lethality, an immune response, neurodegeneration, a sleep abnormality, a circadian abnormality, a learning deficit, a memory deficit, a social behavior deficit, a motor behavior deficit, changes in longevity, changes in intestinal barrier permeability, changes in mitochondrial structure and function, changes in gene expression, changes in enzymatic activity, changes in phosphorylation, changes in post-translational modification, changes in metabolite concentration, changes in cell death, changes in neurotransmitter signaling, and changes in microtubule structure.
2. The method of claim 1 , wherein, in step (ii) the dosing is performed before the impact.
3. The method of claim 1 , wherein, in step (ii) the dosing is performed after the impact.
4. The method of claim 1 , wherein the Drosophila individuals are at least 20 days old.
5. The method of claim 1 wherein step (i) comprises delivering the impact to Drosophila individuals from at least two different genetic backgrounds.
6. The method of claim 5 , wherein step (i) comprises delivering the impact to Drosophila individuals from at least ten different genetic backgrounds.
7. The method of claim 1 , wherein the one or more walled containers contact the strike surface at a predetermined velocity between about 0.5 m/s and about 20 m/s.
8. The method of claim 1 , wherein the acceleration assembly accommodates at least two containers, each container comprising Drosophila individuals.
9. The method of claim 1 wherein the test agent is a transgene.
10. The method of claim 9 , wherein the transgene comprises an expression cassette for an RNAi.
11. The method of claim 9 , wherein the transgene comprises an open reading frame encoding at least one polypeptide.
12. The method of claim 11 , wherein the at least one polypeptide is selected from the group consisting of hAPP, hAbeta1-42, a hTau, a hSynuclein, hHuntingtin, a hTDP-43, a hSOD, hLRRK2, a hGSK3β, and a polyQ polypeptide.
13. The method of claim 9 , wherein the transgene provides in the one or more individuals a non-coding RNA.
14. A method for assaying a test agent in Drosophila , the method comprising the steps of:
(i) delivering to one or more Drosophila individuals an impact to induce closed-head traumatic brain injury (TBI), wherein the step of delivering the impact comprises the steps of:
(a) providing the one or more unrestrained Drosophila individuals inside one or more walled containers secured to a spring-loaded acceleration assembly having first and second ends and defining a deflectable long axis therebetween, the assembly fixedly secured at the first end to a base, the one or more containers secured to the assembly at the second end, the assembly configured to accelerate the one or more secured walled containers toward a strike surface upon deflection of the assembly on the long axis followed by release; and
(b) deflecting the assembly on the long axis and releasing the assembly, thereby accelerating the one or more secured walled containers toward and into contact with the strike surface, whereby the unrestrained Drosophila individuals in the one or more walled containers impact the one or more walled containers;
(ii) dosing the one or more individuals with a test agent before or after the impact; and
(iii) after the impact, assessing closed-head TBI-associated lethality in the dosed one or more Drosophila.
15. The method of claim 14 , wherein, in step (ii) the dosing is performed before the impact.
16. The method of claim 14 , wherein, in step (ii) the dosing is performed after the impact.
17. The method of claim 14 , wherein step (i) comprises delivering the impact to Drosophila individuals from at least two different genetic backgrounds.