J Psychiatry Neurosci 2013; 38(4): 259-268
André L. Takatsu-Coleman, PhD; Camilla L. Patti, PhD; Karina A. Zanin, MSc; Adriano Zager,MSc; Rita C. Carvalho, PhD; Aline R. Borçoi, BPharm; Liliane M.B. Ceccon, MSc; Laís F. Berro, BBiomedSc; Sergio Tufik, PhD; Monica L. Andersen, PhD; Roberto Frussa-Filho, PhD
Takatsu-Coleman, Patti, Zanin, Carvalho, Borçoi, Ceccon, Berro, Frussa-Filho — Departamento de Farmacologia, UNIFESP, São Paulo, Brazil; Patti, Zanin, Zager, Berro, Tufik, Andersen, Frussa-Filho — Departamento de Psicobiologia, UNIFESP, São Paulo, Brazil
Background: Although mood-congruent memory (MCM), or the tendency to recall information consistent with one’s mood, is a robust phenomenon in human depression, to our knowledge, it has never been demonstrated in animals.
Methods: Mice were subjected to social isolation (SI) or crowding for 12 hours and had their depressive-like behaviour (evaluated by the forced swim, tail suspension, sucrose preference and splash tests) or their serum corticosterone concentrations evaluated. In addition, we determined the temporal forgetting curve of the plus-maze discriminative avoidance task (PM-DAT) and examined the effects of SI or crowding on memory retrieval in the PM-DAT. Finally, we verified the effects of metyrapone pretreatment on reinstatement of memory retrieval or on the increase of corticosterone levels induced by SI.
Results: Twelve hours of SI produced depressive-like behaviour, enhanced corticosterone concentration and reinstated retrieval of a forgotten discriminative aversive (i.e., negatively valenced) task. Depressive-like behaviour was crit – ical for this facilitative effect of SI because 12 hours of crowding neither induced depressive-like behaviour nor enhanced retrieval, although it increased corticosterone levels at the same magnitude as SI. However, corticosterone increase was a necessary condition for MCM in mice, in that the corticosterone synthesis inhibitor metyrapone abolished SI-induced retrieval reinstatement.
Limitations: Our study did not investigate the effects of the social manipulations proposed here in a positively valenced task.
Conclusion: To our knowledge, the present paper provides the first evidence of MCM in animal models.
Submitted Mar. 9, 2012; Revised July 5, Sept. 10, 17, 18, 2012; Accepted Sept. 21, 2012.
Acknowledgements: This research was supported by FAPESP/CEPID (Fundação de Amparo à Pesquisa do Estado de São Paulo/Centro de Pesquisa, Inovação e Difusão) grant #1998/14303-3, CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico), CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior) and AFIP (Associação Fundo de Incentivo à Pesquisa). The English language has been proofread and edited by EK Sawyer, but we are entirely responsible for the scientific content. The authors thank Ms. Teotila Amaral, Ms. Marilde Costa, Ms. Claudenice Santos, Mr. Cleomar Ferreira and Mr. Antonio Santos for their capable technical assistance. R. Frussa-Filho, M.L. Andersen and S. Tufik are recipients of the CNPq fellowship.
Competing interests: The authors declare having received grant support as above and as follows: A.L. Takatsu-Coleman, S. Tufik, M.L. Andersen and R. Frussa-Filho from CNPq; C.L. Patti from AFIP and FAPESP; K.A. Zanin, A. Zager, S. Tufik and L.F. Berro from FAPESP; and R.C. Carvalho, A.R. Borçoi and L.M.B. Ceccon from CAPES.
Contributors: A.L. Takatsu-Coleman, S. Tufik, M.L. Andersen and R. Frussa-Filho designed the study. A.L. Takatsu-Coleman, A. Zager, R.C. Carvalho, A.R. Boirçoi, L.M.B. Ceccon and L.F. Berro acquired the data; C.L. Patti, K.A. Zanin and R. Frussa-Filho analyzed it. A.L. Takatsu-Coleman, C.L. Patti, K.A. Zanin, A.R. Boirçoi, L.M.B. Ceccon, L.F. Berro and R. Frussa-Filho wrote the article; C.L. Patti, A. Zager, R.C. Carvalho, S. Tufik, M.L. Andersen and R. Frussa-Filho reviewed it. All authors approved publication.
Correspondence to: R. Frussa-Filho or C.L. Patti, Departamento de Farmacologia – UNIFESP, Rua Botucatu, 862 – Ed. Leal Prado, 1º andar – 04023062, São Paulo, SP, Brazil; firstname.lastname@example.org or email@example.com