Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P08908 (5-HT1A)
 5,574 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The neurobiologic mechanisms whereby the long-term administration of different antidepressant treatments enhance the efficacy of 5-HT synaptic transmission was investigated using an electrophysiologic paradigm in chloral hydrate anesthetized rats. Repeated electroconvulsive shocks (ECS; administered every other day for 14 days) as well as the sustained 21-day administration of the tricyclic antidepressant imipramine (10 mg/kg/day) and of the selective 5-hydroxytryptamine (5-HT) reuptake blocker paroxetine (5 mg/kg/day), increased the suppressant effect of the electrical stimulation of the afferent 5-HT pathway on the firing activity of CA3 hippocampus pyramidal neurons. The long-term treatments with imipramine and ECS, but not with paroxetine, increased the responsiveness of postsynaptic CA3 hippocampus pyramidal neurons to the microiontophoretic application of 5-HT and to that of the selective 5-HT1A receptor ligand 8-OH-DPAT. In contrast, the long-term treatment with paroxetine, but not with imipramine or ECS, attenuated the negative feedback exerted by terminal 5-HT autoreceptors on 5-HT release. This was indicated by two series of experiments. First, the capacity of the acute intravenous injection of the terminal 5-HT autoreceptor antagonist methiothepin to increase the efficacy of the stimulation was abolished in paroxetine-treated rats. Second, the decreased suppressant effect on pyramidal neuron firing activity usually obtained by increasing the frequency of the stimulation from 1 to 5 Hz (shown to be due to an increase in terminal 5-HT autoreceptor activation at the higher frequency) was also reduced in paroxetine-treated rats. The present data confirm and extend those of previous electrophysiologic studies showing that an enhanced 5-HT synaptic transmission is a common end result of long-term administration of various types of antidepressant treatments. Furthermore, they suggest that the mechanisms underlying this enhanced synaptic transmission differ according to the type of treatment administered. Tricyclic antidepressants and ECS enhance 5-HT synaptic transmission by increasing the sensitivity of postsynaptic 5-HT1A receptors, whereas selective 5-HT reuptake blockers produce this effect by reducing the function of terminal 5-HT autoreceptors, thereby increasing the amount of 5-HT released per stimulation-triggered action potential.
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PMID:Presynaptic and postsynaptic modifications of the serotonin system by long-term administration of antidepressant treatments. An in vivo electrophysiologic study in the rat. 2654 64

We studied the effect of repeated treatment with imipramine, amitriptyline (10 mg/kg po, twice daily for 14 days) or electroconvulsive shock (ECS, once daily for 10 days) on the 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT)-induced increase in food intake in free feeding rats. The response to 8-OH-DPAT, measured 24 h after the last administration of the antidepressant drugs or ECS, was not modified. These results, together with literature data, indicate that the presynaptic 5-HT1A receptors involved in the 8-OH-DPAT-induced feeding are not affected by long-term antidepressant administration.
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PMID:Repeated treatment with imipramine, amitriptyline or electroconvulsive shock does not affect the 8-OH-DPAT-induced increase in food intake in free feeding rats. 215 67

1. The effect of chronic administration of antidepressants and electroconvulsive shock (ESC) on the hypothermic response (HTR) induced by 8-hydroxy-2-(di-n-propyramino) tetralin (8-OH-DPAT) as an index of the function of 5-HT1A receptors was investigated in the rat. 2. 8-OH-DPAT dose-dependently decreased the rectal temperature. 3. Pretreatment with parachlorophenylalanine increased HTR. 4. Chronic administration of the antidepressants, trazodone, imipramine, amitriptyline, and fluoxetine had no effect on HTR, whereas administration of clorgyline attenuated HTR significantly. 5. Repeated ECS had no effect on HTR. 6. These results suggest that the action site of 8-OH-DPAT is post-synaptic 5-HT1A receptors and that the chronic administration of some antidepressants and ECS has no direct action on these receptors. 7. Therefore, the antidepressant effects of these drugs are not produced by direct action on postsynaptic 5-HT1A receptors.
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PMID:The effect of chronic administration of antidepressants and electroconvulsive shock on the 5-HT1A receptor mediated hypothermic response induced by 8-OH-DPAT in the rat. 820 89