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2. Brain-derived neurotrophic factor plasma levels in patients suffering frompost-traumatic stress disorder Liliana Dell'Osso a, Claudia Carmassi a,?, Alessandro Del Debbio a, Mario Catena Dell'Osso a, Carolina Bianchi a,
Eleonora da Pozzo a, Nicola Origlia b, Luciano Domenici b,c, Gabriele Massimetti a,
Donatella Marazziti a, Armando Piccinni a
3. PTSD Exposure Combat or military exposure
Child sexual or physical abuse
Terrorist attacks
Sexual or physical assault
Serious accidents, such as a car wreck.
Natural disasters, such as a fire, tornado, hurricane, flood, or earthquake
4. How PTSD Develops How intense the trauma was or how long it lasted
If you lost someone you were close to or were hurt
How close you were to the event
How strong your reaction was
How much you felt in control of events
How much help and support you got after the event
5. Reliving the event (also called re-experiencing symptoms)- memory recall
Avoiding situations that remind you of the event- avoiding stimulation, context
Feeling numb- blunted affect
Feeling keyed up (also called hyperarousal)- over active amygdala? Common Symptoms
6. BDNF- Brain Derived Neurotrophic Factor Protein, from BDNF-gene
Promotes cell survival & regulates proliferation and differentiation of neurons
Stress down regulates BDNF mRNA
Upregulated during learning
Necessary for LTP
7. BDNF cont Role in: growth, development, maintenance and function of neuronal systems
Modulates synaptic plasticity and neurotransmitter release & intracellular signal-transduction
8. BDNF & TrkB TrkB- protein-tyrosine kinase receptor
Together help with LTP (long lasting synaptic plasticity)
Role in learning and memory
Role in pathogenesis of mood and anxiety disorders
9. BDNF and TrkB TrkB- intracellular kinase-activating receptor Signaling pathways of BDNF/TrkB activation in learning and memory. Activity increases BDNF expression and release from pre- and postsynaptic sites. BDNF binds to TrkB receptors located on presynaptic axons, leading to its auto-phosphorylation and activation of the signal transduction MAPK pathway, facilitating neurotransmitter release. BDNF also binds to postsynaptic TrkB, leading to the activation of AMPA and NMDA receptors through the activation of the MAPK and PLC pathways that lead the subsequent phosphorylation of PKA, CAMK, and CREB. Signaling pathways of BDNF/TrkB activation in learning and memory. Activity increases BDNF expression and release from pre- and postsynaptic sites. BDNF binds to TrkB receptors located on presynaptic axons, leading to its auto-phosphorylation and activation of the signal transduction MAPK pathway, facilitating neurotransmitter release. BDNF also binds to postsynaptic TrkB, leading to the activation of AMPA and NMDA receptors through the activation of the MAPK and PLC pathways that lead the subsequent phosphorylation of PKA, CAMK, and CREB.
10. BDNF & TrkB in Rats after PSS Predator Scent Stress – place rat on soiled litter for 10 min. (controls on unsoiled litter)
7 Days later.......
Found in CA1 (of hippocampus):
Down-regulated BDNF mRNA
Upregulated TrkB
Fits-less BDNF - need more receptors!
15. CA1
16. Role of Hippocampus Long term memory and spatial navigation The mossy fibres are the axons of DG granule cells. They extend from the dendate gyrus to CA3 pyramidal cells, forming their major input. MF synapses on CA neurons are large aggregations of termini, with multiple transmitter release sites and post-synaptic densities. Multiple granule cells can synapse onto a single CA3 pyramidal cell.The mossy fibres are the axons of DG granule cells. They extend from the dendate gyrus to CA3 pyramidal cells, forming their major input. MF synapses on CA neurons are large aggregations of termini, with multiple transmitter release sites and post-synaptic densities. Multiple granule cells can synapse onto a single CA3 pyramidal cell.
18. Predisposed to Stress Rats given corticosterone in drinking water had a decrease in NMDA (NR2B), AMPA subunits, GluR2/3 & BDNF
Also looked at fear extinction learning: ok to be in this place now….
19. Receptors NMDA-Ionotropic
21. Oral Corticosterone cont.
22. Oral Corticosterone
23. Take Away Predisposed stress can decrease fear extinction…
Make it harder to learn that “its” O-K.
25. 1st study looking at BDNF w/ PTSD PTSD patients would be expected to have lower BDNF levels
Hippocampus, Amygdala and Cingulate (limbic system) involved
fMRI of PTSD show decreased hippocampal volume
+ correlation blood-brain BDNF levels
26. Methods 18 PTSD, 18 Controls
How long did PTSDers have PTSD?
Blood collected 8-9am (following fast)
ELISA
28. PTSD vs. Control
31. Discussion BDNF lower in PTSD
Limits
Small sample size
BDNF in blood not brain
Possible role of BDNF in PTSD
Predator vs. Prey attitude among individuals exposed to the same stress