Stress and Emotional Arousal Effects
on Memory
basic mechanisms and clinical relevance
Benno Roozendaal
Department of Cognitive Neuroscience
Radboud university medical center
Donders Institute for Brain, Cognition and Behaviour
Radboud University Nijmegen
Nijmegen, The Netherlands
, The formation of long-term emotional memories
“Of some experiences no memory survives the instance of their passage,
others are recalled as long as live endures. How can we explain this?”
William James (1890)
Emotionally arousing experiences are well retained. This is a highly adaptive
process, but could also result in traumatic memories and PTSD.
Emotionally arousing experiences induce the release of norepinephrine in the
basolateral amygdala, inducing a hypervigilant state and promoting memory
consolidation.
This mnemonic effect is enhanced when the situation is so stressful that
glucocorticoid hormones are released and reach the basolateral amygdala.
,Emotional arousal induces activation of stress hormone systems
Epinephrine from adrenal medulla Glucocorticoids from adrenal cortex
↓
Cortisol in humans
adrenaline increases
blood Dream re
Corticosterone in rodents
and glucose in blood .
, Epinephrine administered after training enhances memory of
inhibitory avoidance training the short term
memory consolidates
into a long term
250
memory
Retention latencies (s)
200
after a long time
the adrenaline
150 does not
impart .
100 ↓
50
0
0 10 30 120
Saline Time of posttraining injection (min)
Controls Epinephrine
Gold PE & van Buskirk R, 1975 ↑ ↑
with adrenaline the
→ adrenaline enhances memory
memory consolidation We stay here
.
stays longer
longer