Abstract
Serotonin (5-HT) is a well recognized neurotransmitter in the mammalian central nervous system (CNS). It regulates a variety of physiological functions such as sleep, pain, thermoregulation, feeding, sexual behaviour, and mood. An important component of the 5-HT system is the serotonin transporter SERT which regulates 5-HT homeostasis. Nitric oxide (NO) acts as an intercellular messenger in the CNS, and exerts profound effects on the neuroendocrine functions and behaviour. Within neurons, NO is produced by the activity of one of the isoform of NO synthases present in the organism, namely neuronal NO synthase (nNOS). Although a different anatomical distribution of the central neurons synthetizing 5-HT and NO-producing neurons, functional interactions have been demonstrated between the central 5-HT- and NO-generating systems. Recent data indicate that NO may regulate both the intracellular amount of the amine and its intracellular availability by controlling the release and uptake of 5-HT. In this study, we demonstrated the expression of both SERT and nNOS in the choroid plexuses of buffalo brain by scanning electron microscopy (SEM) and biochemical analyses. Our findings may provide some insights into the mechanism by which the choroid plexus specific barrier acts for the regulation of the most basic neural functions.