, Volume 121, Issue 1, pp 66–72

Active behaviors in the rat forced swimming test differentially produced by serotonergic and noradrenergic antidepressants

  • Michael J. Detke
  • Michael Rickels
  • Irwin Lucki
Original Investigation

DOI: 10.1007/BF02245592

Cite this article as:
Detke, M.J., Rickels, M. & Lucki, I. Psychopharmacology (1995) 121: 66. doi:10.1007/BF02245592


This study demonstrated that distinct patterns of active behaviors are produced by antidepressants that selectively inhibit norepinephrine (NE) or serotonin (5-HT) uptake in the rat forced swimming test (FST). A behavior sampling technique was developed to score the active behaviors swimming, climbing and diving, as well as immobility. The rat's behavior was recorded at the end of each 5-s period during the test session. The sampling technique was both reliable, as demonstrated by test-retest reliability and inter-rater reliability, and valid, as shown by comparison to the timing of behavior durations. Five different antidepressant drugs which block monoamine uptake and two 5-HT1A receptor agonists were shown to decrease immobility in the FST; however, they produced distinct patterns of active behaviors. The selective NE uptake inhibitors desipramine and maprotiline selectively increased climbing, whereas the selective serotonin reuptake inhibitors (SSRIs) fluoxetine, sertraline and paroxetine selectively increased swimming. The 5-HT1A receptor agonists 8-OH-DPAT and gepirone also selectively increased swimming. These results show that:1) SSRIs are not false negatives in the FST; 2) at least two behaviorally distinct processes occur in the FST; and 3) enhancement of NE neurotransmission may mediate climbing in the FST, whereas enhancement of 5-HT neurotransmission may mediate swimming.

Key words

Antidepressants5-HTNESSRIForced swimming testBehavioral despair

Copyright information

© Springer-Verlag 1995

Authors and Affiliations

  • Michael J. Detke
    • 3
  • Michael Rickels
    • 2
  • Irwin Lucki
    • 1
  1. 1.Departments of Psychiatry and PharmacologyUniversity of PennsylvaniaPhiladelphiaUSA
  2. 2.Department of PsychiatryUniversity of PennsylvaniaPhiladelphiaUSA
  3. 3.Department of PsychologyUniversity of PennsylvaniaPhiladelphiaUSA