ABSTRACT
Title
Long-lasting depressive and anxiogenic-like effects in adolescent male rats chronically treated with Nandrolone
Authors
S. Speziali
Doctorate in Neurobiology, Doctorate School in Biological and Medical Sciences
Dept. of Structural and Functional Biology, University of Insubria, Busto Arsizio (VA), Italy
Doctorate in Neurobiology, Doctorate School in Biological and Medical Sciences
Dept. of Structural and Functional Biology, University of Insubria, Busto Arsizio (VA), Italy
Abstract
The clinical use of anabolic androgenic steroids (AAS) has been overshadowed by the illicit abuse of these drugs. Generally abusers are athletes and body-builders who want an enhancement of their performance but, in the last years, an increased number of non-athletes abusers, especially adolescents looking for an easy way to gain muscle and lose body fat, has been observed. It is well documented that adolescence is a critical period where a remodeling of the brain that influence adult behavioral response patterns occurs. Thus, chronic AAS exposure during this developmental window could alter the maturation of hormone sensitive neural system. Despite these evidence, most published papers analyze the effects of ASS abuse at adulthood and only few works investigate these aspects during adolescence
On these bases the aim of the present study is to assess behavioral changes induced by Nandrolone in adolescent male Sprague–Dawley rats.
Adolescent rats (40 post natal days) were treated with Nandrolone (ND, 15 mg/kg i.m. once daily for 14 days) or vehicle (peanut oil) and their behavior was evaluated through a battery of behavioral tests (social interaction, novel object recognition, open field, sucrose preference and forced swim test) during different intervals of time in the washout period:1 week, 2 weeks and 3 weeks after the last injection.
Social activities and aggressive behaviors were not altered in ND-treated group at all the considered intervals of time.
In the novel object recognition test, the group treated with ND showed a low discrimination index 1 and 2 weeks after the last injection, suggestive of an impairment in their cognitive abilities. This deficit disappeared after 3 weeks.
In the open field, ND induced an anxiogenic-like effect 1 week after the last injection that was still present after 3 weeks.
Finally in the forced swim test ND-treated rats showed a remarkable increase in the time spent in immobility 1, 2 and 3 weeks after the last injection suggestive of the presence of a passive coping strategy when subjected to a stressful event, a typical depressive-like behavior. The sucrose preference test, which evaluates the presence of anedonia, showed a trend to reduction in the sucrose preference at 2 weeks, that did not reach the statistical significance.
Taken together our results suggest that chronic ND treatment in adolescent male rats may cause short-term cognitive impairment but long-lasting anxiogenic and depressive-like effects.
On these bases the aim of the present study is to assess behavioral changes induced by Nandrolone in adolescent male Sprague–Dawley rats.
Adolescent rats (40 post natal days) were treated with Nandrolone (ND, 15 mg/kg i.m. once daily for 14 days) or vehicle (peanut oil) and their behavior was evaluated through a battery of behavioral tests (social interaction, novel object recognition, open field, sucrose preference and forced swim test) during different intervals of time in the washout period:1 week, 2 weeks and 3 weeks after the last injection.
Social activities and aggressive behaviors were not altered in ND-treated group at all the considered intervals of time.
In the novel object recognition test, the group treated with ND showed a low discrimination index 1 and 2 weeks after the last injection, suggestive of an impairment in their cognitive abilities. This deficit disappeared after 3 weeks.
In the open field, ND induced an anxiogenic-like effect 1 week after the last injection that was still present after 3 weeks.
Finally in the forced swim test ND-treated rats showed a remarkable increase in the time spent in immobility 1, 2 and 3 weeks after the last injection suggestive of the presence of a passive coping strategy when subjected to a stressful event, a typical depressive-like behavior. The sucrose preference test, which evaluates the presence of anedonia, showed a trend to reduction in the sucrose preference at 2 weeks, that did not reach the statistical significance.
Taken together our results suggest that chronic ND treatment in adolescent male rats may cause short-term cognitive impairment but long-lasting anxiogenic and depressive-like effects.