1. B
rain D
erived N
eurotrophic F
actor

2. Monoamine Steroid Neuropeptide
-Norepinephrine
-Testosterone
-Neuropeptide Y
-Serotonin
-Estrogen
-Hypocretin
-Dopamine
-Corticosterone
-BDNF

3. What does it do? Similar to a neurotransmitter Secreted by cells
Acts on receptors
Binding causes changes in the cell
Autocrine
Paracrine
Receptor
Cell
BDNF

4. Where is it? Definitely in brain and CNS
Small levels in systemic circulation
Hormone action?
Receptors in
Heart
Lungs
Kidney

5. Advice from Dr. Amelia Eisch
GOOD!!!
Increase BDNF
BAD 
Decrease BDNF

6. BDNF BDNF Chronic Stress Affective Disorders Exercise Learning
Relaxation

8. Dendritic Branching…
Control
BDNF added

9. Cycle (Unlikely that synaptic activity is the only catalyst)
Synaptic firing
Ca+ enters cell
NMDA + L-VSCC
(number of non-Ca2+ mechanisms involved)
BDNF produced and released
Sustained BDNF activity strengthens synapses and promotes neuronal growth

10. BDNF signaling Activates genes that turn on LTP systems
Enhance trafficking and cytoskeletal structure
Actin polymerazation
Results in the increased branching and spine density
Brings in new AMPA subunits to existing synapses

11. The Gene – Many mRNAs, One protein
Promoters, alternative splicing, polyadenylation sites
18 mRNAs
Different strands go different places – the mRNA level
Greer & Greenberg 08’
Aid et al. 07’

12. Pruunsild et al. 07’

13. Don’t drown in promoters!
Just remember I & IV
(activity dependent)

14. Epigenetics
‘the study of heritable changes in genome function that occur without a change in DNA sequence‘
“DNA is just a tape carrying information, and a tape is no good without a player. Epigenetics is about the tape player.”

15. Histone Gene Activated Gene Repressed Acetyl groups Methyl groups
Histone Acetyltransferase (HAT)
Histone Deacetylase (HDAC)
Acetyl groups
Gene Activated
Histone
Gene Repressed
Methyl groups
Histone Methyltransferase (HMT)
Histone Demethylase (HDM)

16. Feng Tian, Ann M. Marini, Robert H. Lipsky
NMDA receptor activation induces differential epigenetic modification of BDNF promoters in hippocampal neurons
Feng Tian, Ann M. Marini, Robert H. Lipsky

17. Methods
Hippocampal cell cultures monitored for gene expression of BDNF promoters I & IV (mRNA and DNA)
Primary sources of activating Ca2+ for BDNF gene are NMDA + L-type Voltage Sensitive Calcium Channels
This work uses NMDA activity to induce BDNF transcription NOT L-VSCC

18. Two repressors of BDNF translation
MeCP2
Anchors other repressor enzymes to histone
HDAC1
Removes acetyl groups from histone
MEF2 recruits

19. MeCP2
HDAC1

20. NMDA = exon 1 L-VSCC = exon 4
Cells treated with NMDA over time
NMDA = exon L-VSCC = exon 4

21. Histone Deacetylase (HDAC)
250 nM
Gene Activated
Acetyl groups
Histone Deacetylase (HDAC)
Cells treated with different HDAC inhibitor concentrations

22. DNA Antibody BOOM!!! Segment on interest TF Amplify & run on gel
Glass Bead

23. Time Post NMDA treatment
Exon I
HDAC1
Exon IV
2 Exon I
1 Exon IV

24. MeCP2
Slow action at Exon 1
Exon 2 acted faster. Start with less?

25. Conclusions
Promoters I + IV respond differentially to signals affecting chromatin structure
Same signal may act differently
MeCP2 is temporally different
While NMDA strongly activates Exon 1 realitive to Exon 4, L-VSCC activation would have been interesting