Evaluation of stressor effects on intracranial self-stimulation from the nucleus accumbens and the substantia nigra in a current intensity paradigm.
The effect of uncontrollable footshock was evaluated in animals responding for intracranial self-stimulation from the nucleus accumbens and the substantia nigra (pars compacta) in a descending current intensity paradigm. Responding for brain stimulation from the nucleus accumbens was found to be affected by the stressor at the upper end of the rate-intensity curve. In contrast, responding for brain stimulation from the substantia nigra was unaffected by the stressor at any of the current intensities employed. The variations of responding for self-stimulation from the nucleus accumbens were unrelated to alterations of locomotor activity or rearing. It is suggested that stressor-provoked reductions of responding for intracranial self-stimulation are not a result of the brain stimulation taking on aversive properties, but rather reflect a reduction in the reinforcing or motivational value associated with the stimulation.
D000818:Animals; D001143:Arousal / Q000502:physiology*; D004298:Dopamine / Q000502:physiology; D004597:Electroshock; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009638:Norepinephrine / Q000502:physiology; D009714:Nucleus Accumbens / Q000502:physiology*; D012653:Self Stimulation / Q000502:physiology*; D012686:Septal Nuclei / Q000502:physiology*; D013378:Substantia Nigra / Q000502:physiology*
D004298:Dopamine; D009638:Norepinephrine