The induction of c-Fos in the NTS after taste aversion learning is not correlated with measures of conditioned fear.
The induction of c-Fos-like immunoreactivity (c-FLI) in the nucleus of the solitary tract (NTS) has been shown to be correlated with behavioral expression of a conditioned taste aversion (CTA). However, because this cellular response is also dependent on an intact amygdala, it may represent the activation of a stress-related autonomic response. The present experiments addressed this possibility by evaluating the correlation between c-FLI in the intermediate division of the NTS (iNTS) and 2 measures of conditioned fear: freezing and changes in mean arterial pressure (MAP) and heart rate (HR). Exposure to the taste conditioned stimulus (CS) resulted in a marked induction of c-FLI in the iNTS, whereas exposure to a fear CS did not. Further, exposure to a taste CS did not selectively lead to increases in MAP or HR. Results suggest that induction of c-FLI in the iNTS may reflect the activation of a cell population whose function is unique to the CTA paradigm.
Schafe
G E
GE
W. M. Keck Foundation Laboratory of Neurobiology, Center for Neural Science, New York University, New York 10003, USA. schafe@cns.nyu.edu
Fitts
D A
DA
Thiele
T E
TE
LeDoux
J E
JE
Bernstein
I L
IL
D000818:Animals; D001362:Avoidance Learning / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology; D001931:Brain Mapping; D003214:Conditioning, Classical / Q000502:physiology*; D005239:Fear / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology; D008297:Male; D009043:Motor Activity / Q000502:physiology; D009474:Neurons / Q000502:physiology; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D051381:Rats; D020318:Rats, Long-Evans; D017552:Solitary Nucleus / Q000502:physiology*; D013649:Taste / Q000502:physiology*
D016760:Proto-Oncogene Proteins c-fos