The amygdala - the stress conductor
The amygdala (part of the limbic system) is the central agency for evaluating stressors for threat and triggers the brain’s stress responses.1
Parts of the amygdala are:
- Lateral amygdala (LA)
- Basolateral amygdala (BLA) → calculated action
- Central medial amygdala (CMA) → impulse-driven emotional behavior
The amygdala receives information from many organs and systems about current stressors.
1. Signal input to amygdala (afferents)
The signal inputs of the amygdala are shown after Rensing, Koch, rib.2
→ means in each case an information transfer in the direction of the arrow.
An indented → means an information transfer from the parent point.
-
Monoamine systems
- Dopamine → Amygdala
- Norepinephrine → amygdala
- Serotonin → Amygdala
- Sensory stimuli
- Aversive sensory stimuli:
- → Spinal cord → Nucleus parabrachialis → Amygdala
- → parabrachial nucleus (direct) → amygdala
- Thalamus (sensory and polymodal nuclei) → Amygdala
- Neutral / conditioned sensory stimuli
- Thalamus (sensory and polymodal nuclei)
- → Amygdala
- → cortex (primary sensory nuclei)
- → Amygdala
-
Cortex (association areas)
- → Amygdala
- → primary insular cortex
- → Amygdala
- → Hippocampus
- → Amygdala
- Thalamus (sensory and polymodal nuclei)
- Odors
- Bulbus olfactorius of the cortex
- → Amygdala
due to the great importance of the sense of smell, this is the only stimulus that is directly wired to the medial amygdala3
- → Amygdala
- Bulbus olfactorius of the cortex
- Visual stimuli
- Inferotemporal cortex → amygdala4
- Acoustic stimuli
- Upper temporal lobe → amygdala5
- Aversive sensory stimuli:
2. Signal output from amygdala (efferents)
The signal outputs of the amygdala are shown after Rensing, Koch, rib.2
→ in each case means an information transfer in the direction of the arrow.
- Interstitial nucleus of the stria terminalis
- → hypothalamus (paraventricular nucleus)
- → HPA axis ⇒ stress The HPA axis / stress regulation axis
- → hypothalamus (paraventricular nucleus)
-
Hypothalamus (lateral)
- → rostroventrolateral medulla
- → Sympathetic nervous system
- → Blood pressure increase
- → Blood pressure decrease
- → pupil dilation
- → Skin resistance reduction
- → Sympathetic nervous system
- → rostroventrolateral medulla
- Central cave gray
- → Freezing
- → Analgesia
- Motor trigeminal and facial nucleus
- → anxious or stressed facial expression
- Insular and prefrontal cortex
- → subjective feeling
- → malaise
- → Fear
- Nucleus reticularis pontis caudalis
- → Startle reaction
-
Locus coeruleus
- → Attention
- → Arousal
- → Vigilance
-
Ventral tegmentum
- → Attention
- → Arousal
- → Vigilance
-
Raphe seeds
- → Attention
- → Arousal
- → Vigilance
- Vagus nerve (dorsal nucleus)
- → Parasympathetic nervous system
- → Bladder emptying / micturition
- → Bowel movement / defecation
- → Stomach ulcers
- → Parasympathetic nervous system
- Parabrachial nucleus
- → Increase in respiratory rate (wheezing)
- Unnamed mediation channel
Rensing, Koch, Rippe, Rippe (2006): Der Mensch im Stress; Psyche, Körper, Moleküle; Elsevier Spektrum (heute: Springer), Seite 350 ↥
Rensing, Koch, Rippe, Rippe (2006): Der Mensch im Stress; Psyche, Körper, Moleküle; Elsevier Spektrum (heute: Springer), Seite 109 ↥ ↥
Wittling, Wittling (2012): Herzschlagvariabilität, Frühwarnsystem, Stress- und Fitnessindikator; S. 42 mwNw ↥
Wittling, Wittling (2012): Herzschlagvariabilität, Frühwarnsystem, Stress- und Fitnessindikator; S. 41 ↥
Hebben, Corkin, Eichenbaum, Shedlack (1985): Diminished ability to interpret and report internal states after bilateral medial temporal resection: Case H.M.; Behavioural Neurosience, 99, 1031-1039 ↥ ↥ ↥