Antidepresszivumok, stresszorok es a szerotonin 1A receptor.

Abstract

5-HT1A receptor is a receptor of surprises. Buspirone, an anxiolytic drug with a then yet unidentified mechanism of action had been marketed for years when it was discovered that it is a 5-HT1A partial agonist. Several more years had to pass before it was accepted that this receptor plays the key role in the action mechanism of buspirone. This was followed by further surprises. It was discovered that in spite of its anxiolytic effect buspirone activates the hypothalamic-pituitary-adrenal (HPA) stress axis, furthermore, it increases peripheral noradrenaline and adrenaline concentration via a central mechanism. Thus activation of this receptor leads to ACTH/corticosterone and catecholamine release and also increases beta-endorphine, oxytocin and prolactin secretion while decreasing body temperature, increasing food uptake, eliciting characteristic behavioural responses in rodents and also playing a role in the development of certain types of epilepsy. Human genetic studies revealed the role of 5-HT1A receptors in cognitive processes playing a role in the development of depression such as impulsiveness or response to environmental stress. This exceptionally wide spectrum of effects is attributable to the presence of 5-HT1A receptors in serotonergic as well as other, for example glutamatergic, cholinergic, dopaminergic and noradrenergic neurons. The majority of the effects of 5-HT1A receptors is manifested via the mediation of Gi proteins through the hyperpolarisation or inhibition of the neuron carrying the receptor. 5-HT1A receptors on serotonergic neurons can be found in the somatodendritic area and play a significant role in delaying the effects of antidepressants which is an obvious disadvantage. Therefore the newest serotonergic antidepressants including vilazodone and vortioxetine have been designed to possess 5-HT1A receptor partial agonist properties. In the present paper we focus primarily on the role of 5-HT1A receptors in stress and antidepressant response.