Anglais

Reconstruction of adult neural circuits through embryonic cell transplantation: Towards repair of the motor pathwayFrom A. Gaillard et al (2007) ; A. Gaillard et al (2009) and J.Kallaani et al (2016)

• PMettre proj M1
• Dire à quelle lésion on est
• Bullet point qui corresponde à chaque image
• + mettre les timings
• + mettre - d'images mais + détaillées
• Mettre en perspective test à faire

NE PAS METTRE PAPIER PAS DANS LE POSTER Mais utiliser les papiers en + pr le <M1

BAILLIER Angèle - BONNET Maxence - JOURDAIN Léa - VENDÉ Max

Introduction

Grafted neurons survive and extend long-distance projection (nigrostriatal pathway)

Molecular maturation

Lesions in the adult brain are irreversible because neurons do not regenerate spontaneously. This research demonstrates that transplanting embryonic neurons can rebuild damaged circuits by reactivating axonal guidance signals in adults.

• Indirect presence of mature neurons marker (PLP+)
• Presence of neuronal migration marker (DCX+)
• Synaptic protein expression (synaptophysin+)

Methods

Ongoing differentiation and structural integration into the adult brain.

Experimental design Adult wild type mice received :

Behavioural recovery (nigrostriatal pathway)

• Unilateral lesion of M1 (cortical impact) or nigrostriatal pathway (6-OHDA)
• Transplantation of GFP-expressing embryonic neurons

• Prendre couoe de cerveau pr coupe voie NG striée et M1 après zoom sur cerveau
• + 2 types de neurones transplantées
• Maybe des titres + courts
• Pas mettre figure+ diagrams
• + plus précis dans le schéma
• Grossir les images + réduire taille col gauche
• + clair d'avoir le titre au dessus + en gras
• Mettre des fond différents?

6-OHDA lesions induced severe dopaminergic denervation:

Intragraft GFP+ neurons

• ~100 rotations / 60 min after apomorphine injection, an agonist of D1 and D2 receptor

Analyses performed

• Extend axons along the medial forebrain bundle
• Reinnervate the host striatum

• Immunohistochemistry (GFP, DCX, PLP, synaptophysin and TH)
• Axonal projection tracing
• Behavioral tests (Rotometer apomorphine-induced rotations)

Three months after transplantation:

At 2-3 months post-grafting :

• Rotations reduced by ~94% (p < 0.05)
• Significant restoration of motor function

• Dense and target-specific nigrostriatal projections are established
• Retrograde tracing confirms connectivity with the host tissue

Functional reconstruction of the nigrostriatal pathway.

Abbreviations

Conclusion

Take Home message

• WT : wild type
• M1: primary motor cortex
• 6-OHDA : 6-hydroxydopamine
• GFP: Green fluorescent protein
• DCX : Doublecortin
• TH : Tyrosine hydroxylase
• PLP : Proteolipid protein

Embryonic neuronal grafts :

• Survive in the lesioned adult brain
• Reconstruct the nigrostriatal pathway
• Establish functional synaptic connections
• Restore motor behavior

Embryonic neural grafts enable the structural and functional reconstruction of the adult nigrostriatal pathway.

Neuronal transplantation represents a promising strategy for motor circuit repair.

Sources

• Gaillard, A., Decressac, M., Frappé, I., Fernagut, P. O., Prestoz, L., Besnard, S., & Jaber, M. (2009). Anatomical and functional reconstruction of the nigrostriatal pathway by intranigral transplants. Neurobiology Of Disease, 35(3), 477‑488. https://doi.org/10.1016/j.nbd.2009.07.003

• Gaillard, A., Prestoz, L., Dumartin, B., Cantereau, A., Morel, F., Roger, M., & Jaber, M. (2007). Reestablishment of damaged adult motor pathways by grafted embryonic cortical neurons. Nature Neuroscience, 10(10), 1294‑1299. https://doi.org/10.1038/nn1970

• Kalaani, J., Roche, J., Hamade, E., Badran, B., Jaber, M., Gaillard, A., & Prestoz, L. (2016). Axon guidance molecule expression after cell therapy in a mouse model of Parkinson’s disease. Restorative Neurology And Neuroscience, 34(6), 877‑895. https://doi.org/10.3233/rnn-150587

Embryonic neural crest cell transplantation expressing GFP in mice with lesions in the M1 and nigrostriatal pathway.

Principle

Allows spontaneous locomotor activity in rodents to be observed

Device

• Circular bowl with no corners
• Movements recorded by video tracking or infrared

Parameters analysed

• Distance travelled
• Speed
• Time spent immobile
• Rotations
• Stereotypies.

Applications

Fig XX: Image of the rotameter bowl test

Assessment of motor deficits.

Distribution of GFP graft efferents towards host targets. GFP-immunostained parasagittal sections 8 days (A–D) and three months post-grafting (E–F). (A and E) a dense bundle of GFP+ fibers leaving the transplant. (B and F) GFP+ fibers along the mfb, . (L) Quantification of the number of GFP+ graft efferents towards host targets (n= 12). mfb = Medial forebrain Bundle CPu = Caudate putamen Acb = Nucleus accumbens SVZ = Subventricular zone CX = Cortex

Faire un schéma

Quantification of asymetric turning behaviour after an injection of apomorphine (0.5mg/kg) before lesion, after lesion of the substantia nigra with 6-OHDA and 3 month after transplantation * : P-value <0.05

LNEC

Laboratory of Experimental and Clinical Neuroscience

Study the mechanisms involved in neurological and psychiatric diseases (Parkinson's disease, addictions, neurodevelopmental disorders) in order to develop new therapeutic approaches, using a translational research approach. Projet: Work ranging from cell culture to animal models to clinical research, combining behavioral analysis, neuroanatomy, neurochemistry, electrophysiology, and cellular and molecular biology.

Directed by Mohamed JABER

Maturation indices of the transplant. (a–c) DCX expression in the graft and graft-derived axons.(b) High-power images showing GFP+ soma and processes co-expressing DCX. (d) Double-labeling of GFP (green) and PLP (red) showed several myelinated GFP+ fibers in the cortex. (e) Host synaptophysin terminals (red) were detected in the immediate vicinity of GFP+ cell body (green).(K) Fibers and terminals within the striatum co-expressed also GFP and TH in the cortex Scale bar: b, 30 µm; d, 20 µm; e, 10µm and K, 50µm