Effect of number of tailshocks on learned helplessness and activation of serotonergic and noradrenergic neurons in the rat

Luiz F. Takase, Maria Inês Nogueira, Sondra T. Bland, Michael Baratta, Linda R. Watkins, Steven F. Maier, Casimir A. Fornal, Barry L. Jacobs

Research output: Contribution to journalArticle

48 Scopus citations

Abstract

Adult male albino rats were exposed to varying numbers of tailshocks (0, 10, 50 or 100). The following day, their escape latencies in a shuttlebox were measured in order to estimate the degree of learned helplessness (LH) produced by the varying number of shocks. Only the groups exposed to 50 or 100 shocks displayed evidence of LH. In a parallel experiment, c-fos activation was used to determine the degree of activation of raphe serotonergic neurons (FosIR + 5-HT) and locus coeruleus (LC) noradrenergic neurons (FosIR + TH) produced by the same shock conditions. Compared to unhandled cage controls, all shock groups (0 shocks was a restrained group) significantly activated both raphe and LC neurons. The 50 and 100 shock groups had significantly higher degrees of activation of serotonergic neurons in the rostral raphe groups and the LC than the 0 and 10 shock groups. These data are consistent with the hypothesis that activation of rostral raphe serotonergic neurons and LC noradrenergic neurons beyond a certain threshold may be critical for the development of LH. The relevance of these results for elucidating the neural bases of psychopathology is discussed.

Original languageEnglish (US)
Pages (from-to)299-306
Number of pages8
JournalBehavioural Brain Research
Volume162
Issue number2
DOIs
StatePublished - Jul 30 2005

All Science Journal Classification (ASJC) codes

  • Behavioral Neuroscience

Keywords

  • Depression
  • Inescapable shock
  • Learned helplessness
  • Locus coeruleus
  • Norepinephrine
  • Raphe
  • Serotonin
  • c-fos

Fingerprint Dive into the research topics of 'Effect of number of tailshocks on learned helplessness and activation of serotonergic and noradrenergic neurons in the rat'. Together they form a unique fingerprint.

  • Cite this

    Takase, L. F., Nogueira, M. I., Bland, S. T., Baratta, M., Watkins, L. R., Maier, S. F., Fornal, C. A., & Jacobs, B. L. (2005). Effect of number of tailshocks on learned helplessness and activation of serotonergic and noradrenergic neurons in the rat. Behavioural Brain Research, 162(2), 299-306. https://doi.org/10.1016/j.bbr.2005.04.008