Stressor-induced behavioral alterations in intracranial self-stimulation from the ventral tegmental area: evidence for regional variations.
Exposure to uncontrollable footshock reduced responding for electrical brain stimulation (ICSS) from the ventral tegmental area (VTA) of the CD-1 mouse. Such an effect, however, varied with electrode position in the tegmental field. In both a rate-dependent and a current intensity paradigm, ICSS from the dorsal VTA was reduced immediately, 24 hr and 168 hr following exposure to acute uncontrollable footshock. In contrast, ICSS from the ventral VTA was unaffected by the stressor regimen. These data are consistent with the suggestion that a stressor may reduce the rewarding value ordinarily derived from ICSS. Inasmuch as the stressor differentially affected ICSS from the dorsal and ventral tegmentum, these data provide evidence for a functional differentiation within the midbrain tegmental area.
Zacharko
R M
RM
Department of Psychology, Carleton University, Ottawa, Ontario, Canada.
Kasian
M
M
MacNeil
G
G
Anisman
H
H
D000818:Animals; D004558:Electric Stimulation; D008297:Male; D051379:Mice; D012653:Self Stimulation / Q000502:physiology*; D013312:Stress, Physiological / Q000503:physiopathology*; D013681:Tegmentum Mesencephali / Q000502:physiology*