Details

Autor(en) / Beteiligte

• Ferretti, Carlo
• Blengio, Marinella
• Gamalero, Silvana Ricci
• Ghi, Piera

Titel

Biochemical and behaviour changes induced by acute stress in a chronic variate stress model of depression: the effect of amitriptyline

Ist Teil von

• European journal of pharmacology, 1995-06, Vol.280 (1), p.19-26

Ort / Verlag

Amsterdam: Elsevier B.V

Erscheinungsjahr

1995

Quelle

Elsevier Journal Backfiles on ScienceDirect (DFG Nationallizenzen)

Beschreibungen/Notizen

• This paper examines the biochemical and behaviour changes induced by an acute stress (five 10-s, 1-mA foot-shocks) in three groups of rats: (1) never stressed, (2) subjected to chronic variate stress for 20 days, (3) subjected to the same chronic stress and treated with 5 mg/kg per day amitriptyline. After 15 min, acute stress led to a marked reduction in cortical β-adrenoceptor and 5-HT 2 receptor density, whereas the density of the 5-HT 1A receptors was unchanged. Chronic stress also increased β-adrenoceptor and 5-HT 2 receptor density and had no effect on 5-HT 1A. Acute stress diminished the density of β-adrenoceptors in chronically stressed animals, but did not alter that of the two 5-HT receptor populations. Amitriptyline alone reduced β-adrenoceptor and 5-HT 2 receptor densities only. Acute stress applied to animals treated with amitriptyline reduced 5-HT 1A receptors, and caused a further β-adrenoceptor decrease, but had no further effect on the 5-HT 2 receptors. On behaviour, chronic stress diminished reactivity to the acute stress. This reduction was fully abolished by amitriptyline. An open-field study showed that acute stress reduced motor activity, increased latency times and diminished rearing in the controls, whereas chronic stress reduced motor activity only. No significant changes in behaviour were induced by the acute stress in animals subjected to chronic stress. The combination of chronic stress with amitriptyline was accompanied by a diminution of exploratory activity that persisted after the acute stress. These findings show that chronic variate stress alters some of the biochemical and behavioural responses to a subsequent acute stress and that these alterations are antagonised by amitriptyline.