Stress and pain responses in rats lacking CCK1 receptors.
CCK involvement in stress- and pain-responsiveness was examined by studying the behavior of infant (11-12-days-old) and adult OLETF rats that do not express CCK1 receptors. Infant odor- and texture-preferences were also assessed. We hypothesized that OLETF rats will show behavioral patterns similar to those previously observed after CCK1 antagonist administration. Rate of separation-induced ultrasonic vocalization was significantly greater in OLETF compared to controls, in two separate studies. Infant pups of the two strains did not differ in odor- and texture-preference tests. OLETF rats showed consistently longer hot-plate paw-lift (as infants, in two separate studies) and paw-lick (as adults) latencies.


CONCLUSIONS
OLETF pups vocalized in isolation more than controls and showed relative hypoalgesic responses, evident also in adulthood, in concordance with the pharmacological literature.
Hurwitz
I
I
Interdisciplinary Program in the Brain Sciences, Bar Ilan University, Ramat-Gan, Israel.
Malkesman
O
O
Stern
Y
Y
Schroeder
M
M
Lavi-Avnon
Y
Y
Shayit
M
M
Shavit
Y
Y
Wolf
G
G
Yirmiya
R
R
Weller
A
A
D000375:Aging; D000818:Animals; D001522:Behavior, Animal; D001835:Body Weight; D005260:Female; D008297:Male; D009812:Odorants; D010146:Pain / Q000473:pathology*; D010147:Pain Measurement; D017288:Pain Threshold; D051381:Rats; D011949:Receptors, Cholecystokinin / Q000235:genetics* / Q000502:physiology*; D013312:Stress, Physiological / Q000473:pathology*; D013997:Time Factors
D011949:Receptors, Cholecystokinin