Presynaptic heteroceptors

Laduron, PM (1985) Presynaptic heteroceptors in regulation of neuronal transmission. Biochem. Pharmacol. 34 467 70. 

Figure 1.6 The nomenclature used to describe receptor location on neurones. Starting with Neurone A , neurotransmitter released at the terminals will interact with POSTSYNAPTIC receptors on Neurone B Similarly, neurotransmitter releasedfrom Neurone D will interact with postsynaptic receptor on Neurone A Neurotransmitter releasedfrom Neurone A will also regulate its own release by interacting with the TERMINAL A UTORECEPTOR or affect neuronal firing by interacting with the SOMATODENDRITIC AUTORECEPTOR Release of neurotransmitter from Neurone A can also be regulated by activation of PRESYNAPTIC HETEROCEPTORS on the terminals, which are postsynaptic receptors activated by neurotransmitter from Neurone C...

Administration of 5-HTib receptor agonists increases waking time and reduces REM sleep. This is consistent with recent evidence gathered from 5-HTiB-receptor knockout mice which exhibit more REM sleep and less SWS than the wild-type. Moreover, 5-HTib agonists reduce, while antagonists increase, REM sleep in the wild-type mouse, but neither type of compound has any effect in the knock-outs (Boutrel et al. 1999). Unfortunately, it is not known whether these actions are mediated by presynaptic, postsynaptic or heteroceptors and therefore whether 5-HT activity is increased or decreased. It is also not helped by the limited selectivity of test agents. 

Presynaptic receptor that is activated by a neurotransmitter from an adjacent neuron the type of neurotransmitter activating the heteroceptor differs from that released from the axon. 5-Hydroxyindoleacetic acid, the main metabolite of 5-hydroxytryptamine (serotonin) formed by monoamine oxidase. 

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