Objective: To investigate the effect of central interleukin-1? (IL-1?) on motor behavioral responses in novelty stress rats. Methods: The novelty stress was elicited by novel environmental stimuli with novelty stress box. The intracerebrolventricular (ICV) cannula and microinjection were performed with rat brain stereotaxic system. Movement behaviors of rats were monitored by behavioral radio-telemetry system. As behavior index, mean percent immobility (MPI) was used to assess immobility of rats. Results: The decrease of MPI was remarkably elicited by novel environmental stimuli. In non-stressful condition, ICV anti-IL-1? antibody did not influence the MPI. The decrease of MPI induced by novel environmental stimuli was significantly blocked by ICV pretreatment with anti-IL-1? antibody. In novel stress, MPI of rats was not affected by ICV injection of non-specific IgG. Conclusion: Central interleukin-1? plays an important role in modulation of motor behavioral response to novelty stress.

AIM: To study the central mechanism of intracerebral interleukin-1? in restraint stress-induced pressor response in rats. METHODS: Cardiovascular radio-telemetry system, stereotaxic microinjection system and neuroelectrophysiological methods were used to investigate the role of intracerebral interleukin-1? in pressor response induced by restraint stress, and the relation with the changes of discharge in the rostral ventrolateral medulla (RVL) neuron. RESULTS: The pressor response was induced by restraint stress and was reduced by intracerebral-ventricular injection of (icv) IL-1 receptor antagonist (IL-Ira) in conscious rats. The pressor response was directly induced by IL-1 (icv), which is related to increase of the extracellular discharge frequency in RVL neurons. CONCLUSION: Intracerebral IL-1? mediates pressor response induced by restraint stress, the mechanism may be closely related to RVL.