Behavioral response to novelty correlates with dopamine receptor availability in striatum of Göttingen minipigs.
Behavioral response to novelty in rats has been linked both to dopamine transmission in the ventral striatum, and to propensity to self-administer psychostimulant drugs. In order to probe the relationship between behavioral response to novelty and dopamine systems we have developed a behavioral model for correlation with positron emission tomography (PET) of dopamine transmission in brain of Göttingen minipigs. In the present study, we measured exploration of a novel object by recording the number of contacts, and duration of contact with a novel object, in groups of six male and six female adult minipigs. We hypothesized that these novelty scores would correlate with the amphetamine-evoked dopamine release in ventral striatum, measured 2 weeks later in a PET study of the availability of binding sites for the dopamine D2/3 antagonist [11C]raclopride. There were significant correlations between duration of contact with a novel object and the amphetamine-evoked reductions in binding potential (DeltapB) in the left ventral striatum of the 12 animals; Comparison of results by gender revealed that the correlation was driven mainly by the male group, and was not present in the female group. We interpret these results to show that propensity to explore an unfamiliar object is relatively elevated in pigs with low basal occupancy of dopamine D2/3 receptors by endogenous dopamine, and with high amphetamine-induced occupancy of released dopamine in the male pigs.
Lind
Nanna Marie
NM
Department of Psychiatry, University Hospital of Copenhagen, Bispebjerg, Denmark. nml@cnsr.dk
Gjedde
Albert
A
Moustgaard
Anette
A
Olsen
Aage Kristian
AK
Jensen
Svend Borup
SB
Jakobsen
Steen
S
Arnfred
Sidse Marie
SM
Hansen
Axel Kornerup
AK
Hemmingsen
Ralf Peter
RP
Cumming
Paul
P
D000223:Adaptation, Psychological; D000818:Animals; D002250:Carbon Radioisotopes / Q000378:metabolism; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000378:metabolism*; D005106:Exploratory Behavior / Q000502:physiology*; D005260:Female; D008297:Male; D010551:Personality / Q000502:physiology; D049268:Positron-Emission Tomography; D020891:Raclopride / Q000378:metabolism; D011954:Receptors, Dopamine / Q000378:metabolism*; D012737:Sex Factors; D013552:Swine; D013556:Swine, Miniature; D014018:Tissue Distribution
D002250:Carbon Radioisotopes; D011954:Receptors, Dopamine; D020891:Raclopride