R.I.P. Steve Jobs
description
Transcript of R.I.P. Steve Jobs
R.I.P. Steve Jobs
Hao LiOct.7th 2011
Social Defeat ParadigmSocial Defeat Paradigm
Long–Evans rats
(325–350 g)
Sprague–Dawley
rats(250–275 g)
V.S.
Social Defeat Paradigm
Social Defeat ParadigmSocial Defeat Paradigm5 min fighting or until the
submissionSeparated with wire mesh cage
for 15 min4 consecutive encounters15 min between each encounters
Depressive-like BehaviorsDepressive-like BehaviorsSucrose preference test----
AnhedoniaForced swim test---- Behavioral
DespairContextual fear test----MemorySocial approach and avoidance
test
Sucrose preference testSucrose preference test2 bottles water for 5 days
Increasing concentrations of sucrose (0.25–1%) for 2 days per concentration
Contextual fear testContextual fear test
• For the memory of traumatic event
• Putting the rats and an aggressor in the same cage for 5 min
• Measuring the freezing time
Social approach and Social approach and avoidanceavoidance3 sections each for 5 minSection 1- free walks in the open
fieldSection 2- “no target” Section 3- “target”
Measuring the locomotion and investigating time
Histone ModificationHistone ModificationHistone acetylation makes RNA
polymerase and transcription factors easier to access the promoter region.
Histone ModificationHistone ModificationHistone H3Histone H4
Histone ModificationHistone Modification• H3 Acetylation
Electroconvulsive Seizures
• H4 Acetylation
Upregulation of BDNF Transcription
Downregulation of c-fos Transcription
(Tsankova 2004)
Behavioral TestsBehavioral Tests
Sucrose Preference Test: Both defeated and control rats
similarly preferred increasing sucrose concentrations over water.
Behavioral TestsBehavioral Tests
Forced Swim Test:
Behavioral TestsBehavioral Tests
Social approach and avoidance test
Section 1 Section 2
Behavioral TestsBehavioral Tests
Section 3
Behavioral TestsBehavioral Tests
Contextual fear test:
4 weeks 6 weeks
Sucrose preference testForced swim testContextual fear testSocial approach and avoidance test
Depressive-like Behaviors
Histone ModificationHistone ModificationNo significant changes in H3 acetylation in
amygdala and dorsal profrontal cortex
the ratio of histone H3 acetylation (H3hyp) to total histone H3 (TH3)
amygdala dorsal prefrontal cortex
Histone ModificationHistone Modification
hippocampus
No changes in H4 acetylation and H3 acetylation in the amygdala or dorsal prefrontal cortex
----Highly heterogeneous region----Lack of antibody specificity
Histone ModificationHistone ModificationTwo potential pathways in histone
acetylation: N-methyl-D-aspartic acid receptor (NMDA-R) glucocorticoid receptor (GR)
MK-801----increasing acetylationMifepristone----no significant
changes Former study
showed both of them
blocked the acetylation
Different changes to different stressors
(Chandramohan Y 2007)
Thanks…