Scientific and Therapeutic Aspects of Botulinum Toxin: Illustrations
Chapter 8 - Figure 2
In vivo imaging of mouse sternomastoid endplates after localised injections of sub-lethal amounts of BoNT/A and /F, but not /E, reveals extensive nerve terminal remodeling and switching in synaptic activity between the original nerve endings and their sprouts. Synaptic plasticity induced by BoNT/A was less pronounced with BoNT/F poisoning and not detectable after type E. Injection of 0.5 pg of BoNT/A into mouse sternomastoid muscle resulted in a loss of the ability of the original endplates, stained with 4-di-2-ASP (green) to exo-endocytose FM1-43 (red) on stimulation with 60 mM K+ (A and filled bars in D) and elicited sprouts (arrows) capable of stimulated uptake of this dye (A and empty bars in D). Although a depletion of FM1-43 uptake in BoNT/E (5 pg) poisoned terminals was evident after 1 day (B and E), recovery of endo-/exocytosis occurred by d3 (E) and no sprouts were elicited. Within 1 day of injecting 0.4 ng of BoNT/F, FM1-43 uptake was dramatically reduced at the terminals (C and F); from d7, short sprouts capable of stimulated FM1-43 endocytosis were seen and uptake into the original endings started to resume which was complete at d21,↑ indicate the time of initial onset of nerve-induced muscle tension; scale bars represent 20 µm.
From Brin MF, Hallett M, Jankovic J, editors. Scientific and Therapeutic Aspects of Botulinum Toxin. Philadelphia, Lippincot Williams and Wilkins, 2002
Chapter 8 - Figure 3
Persistence of SNAP-25A and rapid clearance of SNAP-25E in murine motor nerve terminals treated with BoNT/A or /E. Control and toxin-treated endplates were dual-labeled with rhodamine-conjugated ∝-bungarotoxin and anti-SNAP-25A or SNAP-25E antibodies, followed by FITC-conjugated secondary IgGs; fluorescent images were recorded by confocal microscopy. (A) In control sternomastoid muscle, SNAP-25A could not be detected whereas immuno-staining was found after BoNT/A-treatment and it resided within areas occupied by the nAChR (d6-40), as revealed by the overlaid images. (B) Staining of SNAP-25E was apparent in nerve terminals and pre-terminal axons 2 days after BoNT/E injection but became undetectable by d7 post-injection. Bars = 10 µm.
From Brin MF, Hallett M, Jankovic J, editors. Scientific and Therapeutic Aspects of Botulinum Toxin. Philadelphia, Lippincot Williams and Wilkins, 2002
Chapter 8 - Figure 4
Fate of SNAP-25A and SNAP25E at motor nerve endings upon sequential injection of BoNT/E 3 days after type A. Muscle fibres from the control and BoNT/A-treated mouse sternomastoid followed (after 3 days) in the latter case by injection of BoNT/E were dual-labeled by rhodamine-conjugated ∝-bungarotoxin and either anti-SNAP-25A or -SNAP25E IgGs with subsequent visualisation using FITC-conjugated secondary antibodies. Confocal microscopy revealed that SNAP-25A was detectable up to 11 days after BoNT/E injection in a few branches of the motor nerve terminals and pre-terminal axons; this staining was no longer seen 4 days later (d15). SNAP-25E was present at d5 but invisible 11 days after BoNT/E injection. Scale bars represent 10 µm.
From Brin MF, Hallett M, Jankovic J, editors. Scientific and Therapeutic Aspects of Botulinum Toxin. Philadelphia, Lippincot Williams and Wilkins, 2002
Chapter 8 - Figure 9
From Brin MF, Hallett M, Jankovic J, editors. Scientific and Therapeutic Aspects of Botulinum Toxin. Philadelphia, Lippincot Williams and Wilkins, 2002
