Neuronal plasticity

• Neuroplasticity  : is composed of the synaptic plasticity and the intrinsic plasticity
• Functional vs Structural SP = functional is the modification of the functionality of preexisting synapses. Structural is the modification of the nb and or structures of synapses.
• Intrinsic plasticity = modification of the neuronal biophysical properties that changes the neuronal response to synaptic transmission. It can be due to : modifications of channel's activation or expression and is involved in learning process.
• LT and ST plasticity = they can be induced independently to each other or concomitantly. The LTP helps develop the neuronal network, recover the damaged neuronal circuits and participate in learning + memory processes. 
• Synaptic efficacy = capacity of an AP to produce a postsynaptic response while plasticity is the modification of this efficacy.
• SP is bidirectional, has 2 phases and is studied mainly in glut synapses
• Tetanus or tetanic stimulation = high frequency stimulation
• Sources of the calcium needed for induction ?

  Are from VDCC, NMDA meaning ionotropic receptors or metabotropic receptors
• What do you need to do to activate NMDA rc ?

  Remoge the magnesium blockage and then binding of glutamate
• LTD could be due to a partial activation of NMDA
• Hebbian theory is composed of 2 principles : associativity and specificiy
• Associativity in hebbian theory are the plastic modifications that are activated at the same time as other synapses going through plasticity induction.
• Specificity in Hebbian theory means that only the coincident synaptic elements which has been active will undergo plastic modification
• What are the presynaptic principles of expression ?

  The modification of NT quantity
• What are the postsynaptic principles of expression ?

  Modification of expression and functionnality of NT receptors through CamKII
• What happens in the post synaptic element if I have too much calcium ?

  Then CamKII will be activated and production of LTP + AMPA Rc activation too
• What happens in the post synaptic element if I have low calcium ?

  PP1 protein phosphatase inhibits CamKII and production of LTD
• The posphorylation and dephorsphorylation of AMPA receptor changes their permeability
• Induction in the pre synaptic element is either caused by calcium or retrograde signals from the post synaptic element
• Pre synaptic expression involves : modification of permeability of calcium channels and potassic channels or functionality of vesicle release proteins
• The increase of AP duration produces an increase in NT. This can be due to the fact that potassic channels are still closed