Ventral tegmental self-stimulation, sensory reactivity and pain reduction in rats selected for high and low rates of lateral hypothalamic self-stimulation.
Ventral tegmental self-stimulation (VTSS) was studied in 56 male rats of four genetic lines (LC1-Lo, LC1-Hi, LC2-Lo, LC2-Hi), which differed in their inherent tendencies to self-stimulate the lateral hypothalamus. It was found that LC2-Hi rats engage more in VTSS than do rats of the LC2-Lo line. No differences were observed between the LC1-Hi and -Lo lines. In a second experiment, the LC2-Hi and -Lo lines were compared as to peripheral pain thresholds (36 animals) and VT-induced-analgesia (21 animals). Genetically low self-stimulators of the LC2 selection program were found to be more sensitive to acute peripheral pain and to VT analgesic influences than are their high counterparts. Theoretical implications are discussed.
D000818:Animals; D001931:Brain Mapping; D005824:Genetics, Behavioral; D007026:Hypothalamic Area, Lateral / Q000502:physiology*; D010146:Pain / Q000503:physiopathology*; D051381:Rats; D012653:Self Stimulation / Q000502:physiology*; D012684:Sensory Thresholds