The amygdala between sensation and affect: a role in pain

Table 1 Reported changes in the rodent CeA in different pain situations

Pain situation ^a	Changes in the CeA	Reference
Acute somatic stimulations	Changes (mostly excitation) in electrical activity	[22, 23]
Visceral pain
ip acetic acid	- Increased c-fos mRNA expression	[24]
Esophageal acetic acid	- Increased c-Fos immunoreactivity	[25]
Colitis	- Increased neuronal excitability	[26, 27]
	- Enhanced the PB-CeA, but not the BLA-CeA transmission
	- Increased crf mRNA expression
Cystitis	- Increased c-Fos and Krox-24 imunoreactivities	[28, 29]
Cystitis	- Increased crf mRNA expression	[28, 29]
Inflammatory pain
Intraplantar formalin	- Induced ERK activation in the right CeA	[30, 31]
Acid-induced muscle pain	- Increased ERK activation	[32]
Acid-induced muscle pain	- Enhanced the PB-CeA transmission	[32]
Knee joint arthritis	- Increased spontaneous activity in the right CeA	[33–36]
	- Increased neuronal excitability in the right CeA
	- Enhanced the PB-CeA and the BLA-CeA transmission
	- Increased mGluR1 and mGluR5 expression
	- Increased phosphorylation of NR1 subunit
Neuropathic pain
Sciatic nerve ligation or section	- Increased spontaneous and evoked activity differentially in the left and right CeA	[37–41]
	- Enhanced the PB-CeA transmission
	- Increased crf mRNA expression and CRF immunoreactivity
	- Increased glucocorticoid receptor mRNA expression
	- Increased cell proliferation

^a Pain situation: acute somatic stimulations: nociceptive mechanical pinches or thermal stimulations applied on different body parts; ip acetic acid: intraperitoneal injection of acetic acid; colitis: inflammation by intracolonic infusion TNBS (2,4,6-trinitrobenzenesulfonic acid) or zymosan; cystitis: urinary bladder inflammation by intraperitoneal injection of cyclophosphamide; intraplantar formalin: intraplantar injection of diluted formalin in hindpaw; Acid-induced muscle pain: intramuscular injection of acidic saline (pH4) in gastrocnemius; knee-joint arthritis: intraarticular injection of kaolin-caragenean in knee; Sciatic nerve ligation or section: loose or tight ligation of sciatic nerve or spinal roots, or sparing section of roots.

ISSN: 2049-9256