1. התפתחות סינפסות Synaptogenesis Illustrations from:
Development of the Nervous System/ Sanes, Rea, Harris
Golan H. 2010

2. נוירונים מייצרים חלק ניכר מאבני הבנין של הסינפסה
לפני יצירת קשר עם נוירון אחר.
מרגע יצירת המגע בין שני התאים סיגנלים תוך תאיים
משרים את התמיינות הסינפסה החדשה.
המאפיינים של סינפסה מייד עם היווצרה שונים במידה מסוימת
מסינפסה בוגרת. נדרש זמן מה ל"התבגרותן"
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3. Morphological evidences
– detectable just in relative advance stage of synapse formation
- EM.
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6. Physiological evidences – Synapse function
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10. Synapse functional maturation:
Presence of neurotransmitter synthesis and release machinery
Before synaptogenesis.
Neurotransmitter release – occur before synapse formation –
Mechanism mostly vesicular.
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11. Ca dependency
Growth cone
And
Synapse (at all ages)
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12. Adhesion
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15. From growth cone to presynaptic terminal
Neuroligin-1
b-Nerexin
microtubules
Vesicles
frizzled
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16. The elements of the PNS synapses
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17. Innervation of muscle cell by the motor neuron induces:
Increase in the number of receptors
Increase in the amount of receptors clustering
*Specificity
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18. Neural Agrin or muscle Agrin Induces receptor clustering?
Neural agrin induces Ach cluster.
Use of Chick anti-Agrin that block (Function-blocking) the chick Agin.
The clustering was blocked when the motor neuron was from Chick but not when the muscle was from Chick
Golan H. 2010

19. Golan H. 2010 Neural Agrin induces Ach receptors phosphorylation: .
When clusters are exposed to Agrin, MUSK – Agrin receptor is phosphorylated within minutes.
And AChR are phsphorylated within an hours.
Receptor aggregation ocure in a few hours, but the level of phosphorylation decline
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20. Agrin binds to a receptor complex and MaSK is required for clustering
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22. The elements of the CNS synapses
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23. EphB signaling influences Glutamate receptors aggregation In the CNS
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24. Eph -Rs
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25. White – glut application Yellow – size of synaptic currents
Green – synaptic contacts
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26. Neural activity Regulation of receptor expression
Regulation of post and presynaptic transcription
Synaptic strength
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27. Activity dependent ….. Golan H. 2010
The activity dependent signal that supresses extrasynaptic receptors involve ca++ influx and activation of CamKII.
Myogenin, a transcription factor in the muscle is phosphorylated and block transcription in extrasynaptic nuclei.
When motor activity is blocked by TTX, myogenin is not active and extrasynaptic receptors cover the entire muscle
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28. The duration of synaptic potentials decreases during development
Central auditory nucleus.
LSO- lateral superior olive
MNTB – medial nucleus of the trapezoid body
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29. Receptors subunits – regulation with age In all receptor types
Depends on:
Age
Brain region
Activity
Chemiacl interactions (trophic factors)
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30. Glutamatergic synapse maturation
MNDA type glutamate receptors close more rapidly with age.
The recordings were done while GABA a AMPA receptors were blocked
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33. YFP- dendritic spine - green
Murai et al, 2003
Eph A3 on astrocyte – red
Synaptophysin – blue
YFP- dendritic spine - green
A role of astrocyte in
The regulation of spine shape
Golan H. 2010