In this study, we compared the depression-like symptoms induced by olfactory bulbectomy (OBX) in the two inbred Wistar and Long Evans rat strains. We also analyzed the self-regulated oral intake of nicotine in these strains and the effect of nicotine on the depression-like symptoms of olfactory bulbectomy. Furthermore, we compared the antidepressant-like effects of nicotine on Wistar rats to those of transcranial magnetic stimulation (TMS), which has emerged as a therapeutic alternative for depression management. Our results show that Wistar rats develop depression-like symptoms, demonstrated by the forced swim test (FST), 4 weeks after OBX. However, in bulbectomized Long Evans rats these symptoms cannot be assessed due to a higher degree of variability of the swimming behavior of this strain. These results suggest that there are some innate differences in susceptibility to stress between these two rat strains. In Wistar rats, voluntary oral nicotine intake (1.2 mg/(kg day) for 14 days) as well as nicotine administered as a single daily i.p. injection (1.5 mg/(kg day) for 14 days) decrease the depression-like symptoms of OBX. Daily transcranial magnetic stimulation (60 Hz and 0.7 mT for 2 h/day for 14 days) also decreases depression-like symptoms but is less effective than nicotine. In conclusion, our results support the idea that there are possible innate differences for depression susceptibility and that nicotine and TMS may be useful in the treatment of this syndrome.
|Number of pages||6|
|Journal||Brain Research Bulletin|
|Publication status||Published - 5 Sept 2008|
Bibliographical noteFunding Information:
The authors would like to thank Lino E. Aguilar-Ortiz, Diana Millán-Aldaco and Marcela Palomero-Rivero for their technical support. Patricia Vieyra-Reyes was supported by Posgrado en Ciencias Biologicas, UNAM. Yann S. Mineur and Marina R. Picciotto were supported by NIH grants # MH77681, DA13334/AA15632, DA00436 and the NARSAD Foster Bam award. R. Vidaltamayo was supported by Dirección General de Asuntos del Personal Académico, UNAM grant # IN211307.
Copyright 2008 Elsevier B.V., All rights reserved.
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