Stress 2 Flashcards
What are the two kinds of receptors in the limbic system involved in cortisol feedback?
MR and GR
How do the receptors changed gene transcription. Name two ways.
- directly binding to recognition sites in the DNA
2. indirectly via interactions with other transcription factors
What effect does excess cortisol have on the hippocampus?
It will down regulate various cell signals including action of BDNF on synaptic integrity. A treaty for this problem will enhance BDNF and monoamine neuromodulation.
MR - high or low affinity for cortisol?
High!
Do MRs increase decrease of maintain excitability of the hippocampal neurons?
maintain
GR - high or low affinity for cortisol?
low
GR are only when?
with high levels of stress-related cortisol
As cortisol levels increase at later stages of stress, GR activity leads to inhibition or activation of stress response?
Inhibtion
MR - fast or slow response
fast
GR - fast or slow response
slow
What are the three phases of brain stress responses?
Stress, recovery, and adaptation
stress generates responses from where?
the limbic system
After a stress response is generate from the limbic system, where are they projected to?
The OVN in the hypothalamus and the HPA axis
After a stressor, when do cortisol levels peak?
30-45 minutes
In the Stress phase, increased cortisol levels bind to which type of receptors?
MR
The binding of cortisol to MRs has what response in the body?
Enhanced arousal, vigilance, alertness, and attention. (non-genomic action through MRs)
When do the recovery and adaption stages occur?
After 1-2 hours
In the recovery and adaption stages, cortisol decreases but there is still enough to suppress the stress response from the initial phase via which type of receptors? Is it a genomic or nongenomic response?
GR - genomic
What else occurs in the recovery and adaptation phases besides suppression?
consolidation and preservation of info about the stressful event. (Memory!!)
Cortisol facilitated memory and learning is dependent on what brain structure? What else is required for proper learning?
Hippocampus. - TIMING!
Stress within the context of learning release what three things? What do they facilitate with?
NA, CRH, and CORT - all of which facilitate the ongoing precesses of perception and attention in the initial phases of learning
cortisol also initiated a ________ pathways which facilitates consolidation of relevant info and temporarily ______ input of unrelated info.
gene-mediated; inhibits
If stress precede learning, when will the gene-mediates suppression of activity occur?
During the time when you want to learn the new task!
Cortisol feedback on the AMYGDALA: the amygdala stimulates or inhibits the HPA axis during stress?
stimulates
cortisol feedback increases or decreases amygdala’s responses to stress by facilitating its activation by ____(what neurotransmitter?)
increases; NE
NOTE how both _____ and _____ enhance amygdala activity in response to stress.
NE and cortisol…the two limbs of the stress response
Cortisol feedback on the PFC: in acute stress does cortisol activate or inhibits MPFC?
activates
What does activation of the mPFC do in acute stress? 2 things.
improves working memory and helps terminate HPA stress response
During Greater stress, high levels or cortisol do what to working memory?
disrupt it and cause distractibility!
In Chronic Stress are the glucocorticoid receptors down regulated or up regulated in the mPFC?
downregulated