Original ArticlesThe effects of infusion of arginine vasopressin, oxytocin, or their antagonists into the olfactory bulb upon social recognition responses in male rats
Section snippets
Animals
Adult male Wistar rats (270–300 g body weight) were used as subjects in the experiments. The animals were caged individually with free access to food and water and were maintained under a natural light-dark cycle.
Cannula implantation and infusion
All animals were implanted bilaterally with guide cannulae (21 gauge, 10 mm long) directed toward the olfactory bulbs (OB). Implantations were performed using a stereotaxic apparatus while the animals were under halothane anesthesia. Coordinates for cannulae implants were 7.0 mm
Results
Figure 1 contains the social discrimination response profiles for control (A, Ringer’s), AVP (B), and OXT (C) infused animals as tested at the 120 min IEI. Control animals showed quite similar, and statistically non-significant investigation scores toward the same versus novel juveniles (t = 1.39, p = 0.195). By contrast, the amount of investigation directed to the novel juveniles was significantly greater than the same juveniles in animals receiving an infusion of either AVP (t = 3.77, p <
Discussion
The data from the I125-AVP infusion into the OB suggest this peptide remains primarily localized within the OB. Notably, under the present conditions of I125-AVP infusion, no activity was observed within the septal area. The significance of this observation is that the AVP infused into the OB would unlikely diffuse in substantial amounts so as to activate the septal area to exert its effects; a site which has been shown to be particularly responsive to the modulatory effects of these peptides 3
Acknowledgements
This work was supported by funds provided by the Deutscher Akademischer Austauschdienst (DAAD) Fellowship Program (DED) and Deutsche Forschungsgemeinschaft (RL). The help of Patrick Lorscher is appreciated.
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