ABSTRACT
The neurotransmitter serotonin (5-HT) acts as an important regulator of the critical neurodevelopmental processes and thus alterations in 5-HT signaling early promotes permanent structural and functional changes in brain. The selective serotonin reuptake inhibitors (SSRIs), as fluoxetine and citalopram, blocking serotonin transporter (SERT) at the presynaptic neuron, which regulates extracellular 5-HT levels. Evidence suggests that the exposure to SSRIs in the neurodevelopmental period may alters 5-HT signaling sensitivity on food intake control. The aim of the present study was to evaluate the effects of neonatal exposure to fluoxetine on molecular and cellular components of the serotonergic system and food intake control in young animals. Methods: The animals were divided according to experimental manipulation, Fluoxetine Group (FG): male pups received application of fluoxetine (10â¯mg/kg, 10⯵L/g) and Saline Group (SG): male pups received saline application (0.9% NaCl, 10⯵L/g), both throughout lactation (PND1-PND21). They evaluated body weight, food intake, SERT gene and protein expression, serotonin content in the hypothalamus. The neonatal exposure to fluoxetine promoted reduction in body weight, disturb the serotonin hypophagic response, and increase the serotonin and SERT hypothalamic in young animals. We conclude that the changes of components of the serotonergic system by neonatal exposure to fluoxetine may be responsible for disturb the inhibitory action of serotonin on food intake.
Subject(s)
Eating/drug effects , Fluoxetine/pharmacology , Neural Inhibition/drug effects , Selective Serotonin Reuptake Inhibitors/pharmacology , Serotonin Plasma Membrane Transport Proteins/metabolism , Serotonin/metabolism , Synaptic Transmission/drug effects , Age Factors , Animals , Animals, Newborn , Body Weight/drug effects , Citalopram/pharmacology , Female , Food Deprivation , Gene Expression Regulation/drug effects , Hypothalamus/cytology , Hypothalamus/drug effects , Hypothalamus/metabolism , Male , RNA, Messenger/metabolism , Rats , Rats, Wistar , Serotonin Plasma Membrane Transport Proteins/geneticsABSTRACT
The aim of this study was to evaluate the effect of progesterone on the protein expression of α4 subunit of GABA(A) receptor, serotonin transporter (SERT), Akt, Erk, and caspase-3 in the olfactory bulb (OB) of female rats exposed to the forced swimming test (FST). Female rats were injected daily with progesterone (0.4 mg/kg body mass) or vehicle during 2 complete oestrous cycles and exposed to the FST, and the protein expression of GABA(A) receptor α4 subunit, SERT, Akt, Erk, and caspase-3 in the OB were evaluated. Progesterone increased the expression of the α4 subunit in the right OB and decreased its expression in the left OB, although it did not change the expression of other proteins. In summary, our findings indicate that progesterone has an asymmetric modulatory effect on the expression of GABA(A) receptor α4 subunit in the OB. This effect could be related to the antidepressant-like effect of progesterone in female rats.