Rat behavior after chronic variable stress and partial lesioning of 5-HT-ergic neurotransmission: Effects of citalopram

• Published in: Progress in neuro-psychopharmacology & biological psychiatry Vol. 32; no. 1; pp. 164 - 177
• Main Authors: Tõnissaar, Margus, Mällo, Tanel, Eller, Marika, Häidkind, Riina, Kõiv, Kadri, Harro, Jaanus
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 2008; Elsevier
• Subjects: Adult and adolescent clinical studies; Analysis of Variance; Animals; Anxiety - drug therapy; Anxiety - etiology; Behavior, Animal - drug effects; Biogenic Monoamines - metabolism; Biological and medical sciences; Brain Injuries - chemically induced; Brain Injuries - complications; Brain Injuries - drug therapy; Brain Injuries - pathology; Chronic variable stress; Citalopram; Citalopram - therapeutic use; Depression; Disease Models, Animal; Drug Interactions; Exploratory Behavior - drug effects; Food Preferences - drug effects; Frontal Lobe - drug effects; Frontal Lobe - injuries; Frontal Lobe - metabolism; Hydroxyindoleacetic Acid - metabolism; Interpersonal Relations; Male; Medical sciences; Mood disorders; Neuropharmacology; p-Chloroamphetamine; Parachloroamphetamine; Pharmacology. Drug treatments; Psychoanaleptics: cns stimulant, antidepressant agent, nootropic agent, mood stabilizer; Psychoanaleptics: cns stimulant, antidepressant agent, nootropic agent, mood stabilizer..., (alzheimer disease); Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Psychopharmacology; Rats; Rats, Sprague-Dawley; Serotonin; Serotonin - metabolism; Serotonin Uptake Inhibitors - therapeutic use; Stress, Psychological - drug therapy; Sucrose - administration & dosage; Swimming; Parachloroamphetamine; CVS; Serotonin; PLSD; Rats; CNS; Depression; PCA; Citalopram; SSRI; 5-HIAA; ANOVA; CRF; Chronic variable stress; HPA; 5-HT; HPLC; Mood disorder; Rat; Psychotropic; Rodentia; Reuptake inhibitor; Stress; Selective serotonin reuptake inhibitor; Vertebrata; Chronic; Mammalia; Animal; Neurotransmitter; Antidepressant agent; Behavior; Neurotransmission
• ISSN: 0278-5846; 1878-4216
• DOI: 10.1016/j.pnpbp.2007.08.001

Deficits in serotonergic (5-HT-ergic) neurotransmission and stressful life events have been implicated in affective disorders, and chronic variable stress (CVS) can elicit behavioral changes reminiscent of increased emotionality, anxiety and atypical depression after partial 5-HT depletion. This study examined the effect of chronic citalopram treatment (10 mg/kg daily) on these changes. Parachloroamphetamine (PCA) (2 mg/kg) reduced the levels of 5-HT and 5-hydroxyindoleacetic acid (5-HIAA) in the frontal cortex, increased anxiety in the social interaction test, and increased activity in the open field. CVS reduced social activity in the social interaction test and immobility time in the forced swimming test. Reduction of excrements left during immobilization indicated partial adaptation with the CVS. Specific stressors had different effects on body weight gain, shorter lasting stressors having a smaller effect in general than those that lasted longer. Combination of CVS and PCA increased sucrose intake after two weeks of stress. In addition, combination of the two treatments reduced diving in the forced swimming test. Citalopram prevented the increase in sucrose consumption in the PCA + CVS rats, and in 5-HT-depleted animals blocked the increase in struggling and reduced the number of defecations in the forced swim test. In conclusion, citalopram treatment prevented several effects of either 5-HT depletion or combined PCA + CVS treatment, suggesting that these behavioral changes could be used in studies on the neural mechanisms underlying emotional behavior that may have relevance to the neurobiology of depression.