The role of the central nucleus of the amygdala in nociception and aversion.
The role of the central nucleus of the amygdala in nociception--conditioned and unconditioned aversion--was studied. Rats received microinjection of vehicle or the N-type Ca2+ channel blocker omega-conotoxin GVIA (0.2 microg/250 nl) into the central amygdaloid nucleus prior to intra-plantar injection of formalin, ultrasound exposure or immediately prior to the acquisition phase of an aversive conditioning trial. Intra-amygdala omega-conotoxin GVIA resulted in an earlier onset of nociceptive response to formalin and increased nociceptive behaviour during the first 5 min. Omega-conotoxin GVIA significantly reduced conditioned freezing behaviour with no effect on ultrasound-induced unconditioned aversive behaviour. These data indicate that N-type Ca2+ channels in the central amygdaloid nucleus play a role in mediating behavioural responses to nociceptive and conditioned aversive stimuli.
Finn
David P
DP
Institute of Neuroscience, School of Biomedical Sciences, University of Nottingham Medical School, Queen's Medical Centre, UK. david.finn@nottingham.ac.uk
Chapman
Victoria
V
Jhaveri
Maulik D
MD
Samanta
Sudip
S
Manders
Thomas
T
Bowden
Jay
J
Matthews
Lucy
L
Marsden
Charles A
CA
Beckett
Simon R G
SR
D000679:Amygdala / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects / Q000502:physiology*; D003213:Conditioning, Psychological / Q000187:drug effects / Q000502:physiology*; D007103:Immobilization / Q000502:physiology; D008297:Male; D010147:Pain Measurement / Q000187:drug effects / Q000379:methods*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020866:omega-Conotoxin GVIA / Q000494:pharmacology
D020866:omega-Conotoxin GVIA