Memory impairment induced by sodium fluoride is associated with changes in brain monoamine levels.
Previous studies suggest that sodium fluoride (NaF) can impair performance in some memory tasks, such as open-field habituation and two-way active avoidance. In the present study, we evaluated the effect of NaF intake (100 ppm in drinking water for 30 days) and its short-term (15 days) withdrawal on open-field habituation and brain monoamine level. Adult male rats were allocated to three groups: tap water (NaF 1.54 ppm) for 45 days (control group); 15 days of tap water followed by NaF for 30 days; and NaF for 30 days followed by 15 days of tap water. The results showed that NaF impairs open-field habituation and increases noradrenaline (NA) and serotonin (5-HT) in the striatum, hippocampus and neocortex. Dopamine (DA) increase was restricted to the striatum. Short-term NaF withdrawal did not reverse these NaF-induced changes, and both NaF treatments led to a mild fluorosis in rat incisors. No treatment effect was seen in body weight or fluid/water consumption. These results indicate that sodium fluoride induces memory impairment that outlasts short-term NaF withdrawal (2 weeks) and may be associated with NA and 5-HT increases in discrete brain regions.
Pereira
Marcela
M
Laboratório de Fisiologia e Farmacologia do Sistema Nervoso Central, Departamento de Farmacologia, Setor de Ciências Biológicas, Universidade Federal do Paraná, Centro Politécnico, P.O. Box 19031, Curitiba, PR 81540-990, Brazil.
Dombrowski
Patrícia A
PA
Losso
Estela M
EM
Chioca
Lea R
LR
Da Cunha
Cláudio
C
Andreatini
Roberto
R
D000818:Animals; D015306:Biogenic Monoamines / Q000378:metabolism; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D008297:Male; D008569:Memory Disorders / Q000139:chemically induced / Q000378:metabolism*; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D009638:Norepinephrine / Q000378:metabolism*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000378:metabolism*; D012969:Sodium Fluoride / Q000633:toxicity*
D015306:Biogenic Monoamines; D012701:Serotonin; D012969:Sodium Fluoride; D004298:Dopamine; D009638:Norepinephrine