Comparison of neurotensin levels, receptors and actions in LS/Ibg and SS/Ibg mice.
Neurotensin (NT), injected centrally, markedly enhances sensitivity to ethanol-induced anesthesia in SS but not in LS mice (4). Since LS and SS mice were bred selectively for differential sensitivity to ethanol, these findings suggest that neurotensinergic neuronal processes mediate some of ethanol's actions and that LS and SS mice might differ genetically in neurotensinergic systems. Indeed, in biochemical studies it was shown that LS and SS mice differ in NT-like immunoreactivity in specific brain regions, i.e., hypothalamus, and in NT receptor densities (Bmax) in frontal cortex and striatum. In other experiments LS and SS mice differed in behavioral responses to centrally administered NT. Intracerebroventricular (ICV) administration of NT produced dose-dependent changes in motor activity, hypothermia, and analgesia in both LS and SS mice. SS mice appeared to be more sensitive than LS to NT-induced analgesia but not hypothermia. Neurotensin increased or decreased locomotor activity in both SS and LS mice following intraventral tegmental area or ICV administration, respectively. The results indicate that LS and SS mice, which were selectively bred for differences in ethanol sensitivity, differ genetically in NT concentrations, receptor densities in specific brain regions, and in some receptor-mediated behavioral responses to NT.
Erwin
V G
VG
Alcohol Research Center, School of Pharmacy, University of Colorado, Boulder 80309.
Jones
B C
BC
D000698:Analgesia; D000818:Animals; D001831:Body Temperature / Q000187:drug effects; D001921:Brain / Q000378:metabolism*; D001923:Brain Chemistry; D002552:Cerebral Ventricles / Q000187:drug effects / Q000502:physiology; D002851:Chromatography, High Pressure Liquid; D007276:Injections, Intraventricular; D007700:Kinetics; D008297:Male; D051379:Mice; D008817:Mice, Mutant Strains; D009496:Neurotensin / Q000008:administration & dosage / Q000032:analysis* / Q000494:pharmacology; D009928:Organ Specificity; D011863:Radioimmunoassay; D018028:Receptors, Neurotensin; D017981:Receptors, Neurotransmitter / Q000378:metabolism*; D013045:Species Specificity
D018028:Receptors, Neurotensin; D017981:Receptors, Neurotransmitter; D009496:Neurotensin