Age differences in the impact of forced swimming test on serotonin transporter levels in lateral septum and dorsal raphe.
BACKGROUND
Forced swimming test (FST) is an animal model which evaluates behavioral despair and the effect of antidepressants such as the selective serotonin reuptake inhibitors; the FST modifies the expression of some receptors related to antidepressant response, but it is not known whether serotonin transporter (SERT), their main target, is affected by this test in animals of different ages. Antidepressant response has shown age-dependent variations which could be associated with SERT expression. The aim of the present study was to analyze changes in the SERT immunoreactivity (SERT-IR) in dorsal raphe and lateral septum of male rats from different age groups with or without behavioral despair induced by their exposure to the FST, since these two structures are related to the expression of this behavior.


METHODS
Prepubertal (24 PN), pubertal (40 PN), young adult (3-5 months) and middle-aged (12 months) male rats were assigned to a control group (non-FST) or depressed group (FST, two sessions separated by 24 h). Changes in SERT-IR in dorsal raphe and lateral septum were determined with immunofluorescence.


RESULTS
Pubertal and middle-aged rats showed higher levels of immobility behavior compared to prepubertal rats on the FST. SERT-IR showed an age-dependent increase followed by a moderate decrease in middle-aged rats in both structures; a decreased in SERT-IR in lateral septum and dorsal raphe of pubertal rats was observed after the FST.


CONCLUSIONS
Age differences were observed in the SERT-IR of structures related to behavioral despair; SERT expression was modified by the FST in lateral septum and dorsal raphe of pubertal rats.
Rosa-Elena
RE
Ulloa
Aliyeri
A
Díaz-Valderrama
Jaime
J
Herrera-Pérez
Martha
M
León-Olea
Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Calzada México-Xochimilco 101, Col, San Lorenzo Huipulco, Delegación Tlalpan, Mexico City 14370, Mexico. lucia@imp.edu.mx.
Lucía
L
Martínez-Mota
D000367:Age Factors; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D008297:Male; D011903:Raphe Nuclei / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012686:Septal Nuclei / Q000378:metabolism*; D050486:Serotonin Plasma Membrane Transport Proteins / Q000378:metabolism*; D013312:Stress, Physiological / Q000502:physiology*; D013315:Stress, Psychological / Q000378:metabolism*; D013550:Swimming
D050486:Serotonin Plasma Membrane Transport Proteins