Single Exposure to a Serotonin 1A Receptor Agonist, (+)8-Hydroxy-2-(di-n-propylamino)-tetralin, Produces a Prolonged Heterologous Desensitization of Serotonin 2A Receptors in Neuroendocrine Neurons in Vivo

Abstract

We previously demonstrated colocalization of serotonin 1A (5- . This is the first in vivo demonstration of a prolonged heterologous intracellular desensitization of 5-HT 2A receptors after acute activation of 5-HT 1A receptors. These findings may provide insight into the long-term heterologous interactions between 5-HT 1A and 5-HT 2A receptor signaling that could occur in response to antidepressants, antipsychotics, or drugs of abuse that target these receptor subtypes.HTSerotonin (5-HT), a known stimulator of the hypothalamicpituitary-adrenal axis, plays an important role in mood disorders and impulse control (Carrasco and Van de Kar, 2003). Among the seven families of serotonin receptors, changes in hypothalamic serotonin 1A (5-HT 1A ) receptors and serotonin 2A (5-HT 2A ) receptors have been associated with the etiology of mood disorders, the therapeutic effect of antidepressants, and the effects of drugs of abuse (Levy et al., 1994;Stockmeier et al

Effect of yokukansan, a traditional Japanese medicine, on social and aggressive behaviour of para-chloroamphetamine-injected rats

“…This result suggests that the improvement brought about by yokukansan in aggressive behaviour or head‐twitch response is not due to its direct antagonism of 5‐HT2A receptors. Recently, Carrasco et al 29 . and Wieland et al 35 .…”

“…We previously demonstrated that 5‐HT and 5‐HIAA concentrations are decreased in most regions of the brain by a single injection of PCA 20 . In this study, the 5‐HT concentration and high‐K + ‐elicited 5‐HT release were examined in the hypothalamus as a representative of the terminal areas of serotonergic innervation, because the hypothalamus is known to be important in regulating aggressive response and emotional behaviour 28,29 as well as an area of the brain rich in 5‐HT 30 . PCA decreased both the 5‐HT concentration and 5‐HT release in the hypothalamus.…”

Activity-dependent serotonergic excitation of callosal projection neurons in the mouse prefrontal cortex

“…2A receptors display a lower affinity for 5-HT, and are more prone to agonist-induced desensitization, than are 1A receptors (for review, see Zifa and Fillion, 1992), suggesting that tonic release of low concentrations of 5-HT may preferentially inhibit overall cortical output. However, 1A and 2A receptors are susceptible to heterologous desensitization (Zhang et al, 2001; Carrasco et al, 2007), raising the possibility of complex interaction among 1A and 2A signaling in vivo . Additional studies will be necessary to explore the response of COM and CPn neurons to tonic exposure to physiological concentrations of 5-HT, and to endogenous release of 5-HT in vivo .…”

Contribution of brain dopamine, serotonin and opioid receptors in the mechanisms of neuroimmunomodulation: Evidence from pharmacological analysis

“…A number of studies have found that these interactions may play an important role in the control of some physiological functions including behavioral reactions and hypothalamic neurosecretion [88][89][90]. Its disturbances have been reported to underlie a variety of mental disorders [91,92].…”

“…It is established that the clinical efficacy of classical antidepressants, selective inhibitors of 5-HT reuptake, at least partly, is provided by their ability to restore a disturbed balance between the 5-HT-receptor subtype [93]. Some authors have shown the potentiating interactions between 5-HT 1A -and 5-HT 2A -receptors, while others indicated functional opposition or antagonistic interactions [87][88][89][90]93]. As was demonstrated recently, the genes encoding the two receptor subtypes are involved in the process of their interaction.…”