title: Strain differences in dopamine receptor function and the initiation of movement.
abstract: The relationship between voluntary movement initiation (VMI) and caudate nucleus dopamine receptor dynamics was analyzed in two rat strains. Charles River CD/F F-344 (CR-CD/F) and Zivic-Miller CD (ZM-CD) rats (male, 125-150 g) were trained to rapidly release and reset a response lever to avoid electric shock. Whereas 86% of all CR-CD/Fs completed training, only 43% of the ZM-CDs were able to do so. Of those rats completing training, the CR-CD/Fs showed marginally higher avoidance percentage and significantly faster VMI latencies. Physiologically, the more behaviorally-successful CR-CD/Fs showed significantly higher affinity for binding than the trained ZM-CDs and the large group of ZM-CDs which could not be successfully trained. In contrast, the trained ZM-CDs showed significantly higher density of dopamine receptors Bmax than the ZM-CDs which failed to train and the trained CR-CD/Fs. The behavior-physiology continuum is summarized as follows: CR-CD/F Rats = highest affinity and lowest Bmax--rapid, highest percentage avoidance; Trained ZM-CD Rats = lowest affinity and highest Bmax--slower, high percentage avoidance; ZM-CD rats that failed training = intermediate affinity and Bmax--avoidance failure.
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D003342:Corpus Striatum / Q000378:metabolism; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D051381:Rats; D011916:Rats, Inbred F344; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000502:physiology*; D013045:Species Specificity
chemical_list: D011954:Receptors, Dopamine