Skip to main content
Log in

Chronic treatment with fluvoxamine by osmotic minipumps fails to induce persistent functional changes in central 5-HT1A and 5-HT1B receptors, as measured by in vivo microdialysis in dorsal hippocampus of conscious rats

  • Original Investigation
  • Published:
Psychopharmacology Aims and scope Submit manuscript

Abstract

This study investigated the alterations of the 5-HT1A and 5-HT1B autoreceptor function following chronic treatment with fluvoxamine using osmotic minipumps. The 5-HT1A and 5-HT1B autoreceptor function were studied using microdialysis in the dorsal hippocampus. The effect of the 5-HT1A receptor agonist 8-OH-DPAT (0.3 mg/kg, SC) and the 5-HT1B receptor agonist RU-24969 (100 nM through the dialysis probe for 30 min) on 5-HT release was compared with rats chronically treated with saline. 8-OH-DPAT decreased 5-HT release to 55% and 60% of baseline, while RU-24969 decreased 5-HT release to 66% and 70% of baseline value in the saline and fluvoxamine group, respectively. In both cases, differences between the saline and fluvoxamine groups were not statistically significant. Plasma levels of fluvoxamine after 21 days of treatment ranged from 3 to 5 ng/ml. Fluvoxamine concentration in rat brain during treatment was estimated between 100 and 200 nM, which approximates to the IC50 value of fluvoxamine on the 5-HT transporter in synaptosomes and is 50 times higher than the Kd value for the 5-HT reuptake site. In conclusion, no evidence was found for changes in 5-HT1A,B receptor function using 8-OH-DPAT and RU-24969 as probes after continuous treatment with fluvoxamine by means of osmotic minipumps.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  • Bel N, Artigas F (1993) Chronic treatment with fluvoxamine increases extracellular serotonin in frontal cortex but not in raphe nuclei. Synapse 15:243–245

    Article  PubMed  Google Scholar 

  • Blier P, de Montigny C (1987) Modification of 5-HT neuron properties by sustained administration of the 5-HT1A agonist gepirone: electrophysiological studies in the rat brain. Synapse 1: 470–480

    Article  PubMed  Google Scholar 

  • Bonvento G, Scatton B, Claustre Y, Rouquier L, (1992) Effect of local injection of 8-OH-DPAT into the dorsal or median raphe nuclei on extracellular levels of serotonin in serotonergic projection areas in the rat brain. Neurosci Lett 137:101–104

    Article  PubMed  Google Scholar 

  • Bosker FJ, Donker MG, Klompmakers AA, Kurata K, Westenberg HGM (1994) 5-Hydroxytryptamine release in dorsal hippocampus of freely moving rats: modulation by pindolol. Prog Neuro psychopharmacol Biol Psychiatry 18:765–778

    Google Scholar 

  • Chaput Y, de Montigny C, Blier P (1986) Effects of a selective 5-HT reuptake blocker, citalopram, on the sensitivity of the 5-HT autoreceptors: electrophysiological studies in the rat. Naunyn-Schmiedebergs Arch Pharmacol 333:342–345

    Article  PubMed  Google Scholar 

  • Chaput Y, Blier P, de Montigny C (1988) Acute and long-term effects of antidepressant serotonin (5-HT) reuptake blockers on the efficacy of 5-HT neurotransmission: electrophysiological studies in the rat central nervous system. Adv Biol Psychiatry 17:1–17

    Google Scholar 

  • Chaput Y, de Montigny C, Blier P (1991) Presynaptic and postsynaptic modifications of the serotonergic system by long-term administration of antidepressant treatments. Neuropsychopharmacology 5:219–229

    PubMed  Google Scholar 

  • Griebel G, Moreau JL, Jenck F, Misslin R, Martin JR (1994) Acute and chronic treatment with 5-HT reuptake inhibitors differentially modulate emotional responses in anxiety models in rodents. Psychopharmacology 113:463–470

    PubMed  Google Scholar 

  • Leonard BE (1992) Pharmacological differences of serotonin reuptake inhibitors and possible clinical relevance. Drugs 43:3–10

    PubMed  Google Scholar 

  • Lesch KP, Aulakh CS, Wolozin BL, Tolliver TJ, Hill JL, Murphy DL (1993) Regional brain expression of serotonin transporter mRNA and its regulation by reuptake inhibiting antidepressants. Mol Brain Res 17:31–35

    Article  PubMed  Google Scholar 

  • Malagie I, Jacquot C, Gardier AM (1992) In vivo release of scrotonin at fontocortical nerve terminals evoked by electrical stimulation of the dorsal raphe nucleus: effect of repeated administration of fluoxetine. Abstract 2nd International Symposium on Serotonin, Houston, p 47

  • Montero D, de Felipe MC, del Rio J (1991) Acute or chronic antidepressants do not modify125I-cyanopindolol binding to 5-HT1B receptors in rat brain. Eur J Pharmacol 196: 327–329

    Article  PubMed  Google Scholar 

  • Moret C, Briley M (1990) Serotonin autoreceptor subsensitivity and antidepressant activity. Eur J Pharmacol 180: 351–356

    Article  PubMed  Google Scholar 

  • Pandey SC, Isaac L, Davis JM, Pandey GN (1991) Similar effects of treatment with desipramine and electroconvulsive shock on 5-hydroxytryptamine1A receptors in rat brain. Eur J Pharmacol 202:221–225

    Article  PubMed  Google Scholar 

  • Paxinos S, Watson C (1982) The rat brain in stereotoxic coordinates, Academic Press, New York

    Google Scholar 

  • Santiago M, Westérink BHC (1990) Characterization of the in-vivo release of dopamine as recorded by different types of intracerebral microdialysis probes. Naunyn-Schmiedeberg's Arch Pharmacol 342:407–414

    Article  Google Scholar 

  • Schechter LE, Bolanos FJ, Gozlan H, Lanfumay L, Haj-Dahmane S, Laporte AM, Fattaccinic, Hamon M (1990) Alterations of central serotonergic and dopaminergic transmission in rats chronically treated with ipsapirone: biochemical and electrophysiological studies. J Pharmacol Exp Ther 255:1335–1347

    PubMed  Google Scholar 

  • Sharp T, Bramwell SR, Grahame-Smith DG (1989a) 5-HT1 agonists reduce 5-hydroxytryptamine release in rat hippocampus in vivo as determined by brain microdialysis. Br J Pharmacol 96:283–290

    PubMed  Google Scholar 

  • Sharp T, Bramwell SR, Hjorth S, Grahame-Smith DG (1989b) Pharmacological characterization of 8-OH-DPAT-induced inhibition of rat hippocampal 5-HT release in vivo as measured by microdialysis. Br J Pharmacol 98:989–997

    Google Scholar 

  • Sharp T, Bramwell SR, Clark D, Grahame-Smith DG (1989c) In vivo measurements of extracellular 5-hydroxytryptamine in hippocampus of the anaesthetized rat using microdialysis: changes in relation to 5-hydroxytryptaminergic neuronal activity. J Neurochem 53:234–240

    PubMed  Google Scholar 

  • Sleight AJ, Smith RJ, Marsden CA, Palfreyman MG (1989) The effects of chronic treatment with amitriptyline and MDL 72394 on the control of 5-HT release in vivo. Neuropharmacology 28:477–480

    Article  PubMed  Google Scholar 

  • Sotelo C, Cholley B, El Mestikawy S, Gozlan H, Harmon M (1990) Direct immunohistochemical evidence of the existence of 5-HT1A autoreceptors on serotoninergic neurons in the midbrain raphe nuclei. Eur J Neurosci 12:1144–1154

    Google Scholar 

  • Sprouse JS, Aghajanian GK (1987) Electrophysiological responses of serotonergic dorsal raphe neurons to 5-HT1A and 5-HT1B agonists. Synapse 1:3–9

    Article  PubMed  Google Scholar 

  • Welner SA, de Montigny C, Desorches J, Desjardins P, Suranyi-Cadotte BE (1989) Autoradiographic quantification of serotonin (5-HT1A) receptors following long-term antidepressant treatment. Synapse 4:347–352

    Google Scholar 

  • Westenberg HGM, den Boer JA (1993) New findings in the treatment of panic disorder. Pharmacopsychiatry 26:30–33

    Google Scholar 

  • Westenberg HGM, den Boer JA (1994) The neuropharmacology of anxiety: a review on the role of serotonin. In: Den Boer JA, Sitsen JM (eds) Handbook of depression and anxiety. Marcel Dekker, New York, pp 405–447

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Bosker, F.J., van Esseveldt, K.E., Klompmakers, A.A. et al. Chronic treatment with fluvoxamine by osmotic minipumps fails to induce persistent functional changes in central 5-HT1A and 5-HT1B receptors, as measured by in vivo microdialysis in dorsal hippocampus of conscious rats. Psychopharmacology 117, 358–363 (1995). https://doi.org/10.1007/BF02246110

Download citation

  • Received:

  • Revised:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF02246110

Key words

Navigation