The Yohimbine-induced Anticonflict Effect in the Rat, Part II. Neurochemical Findings

Overview

Journal J Neural Transm Gen Sect

Specialties Neurology
Physiology

Date 1995 Jan 1

PMID 8748666

Citations 3

Authors

A Soderpalm

F Ehrenstrom

B Soderpalm

Affiliations

Soon will be listed here.

Abstract

In a companion paper the alpha 2-adrenoceptor antagonist yohimbine was found to produce a dose-dependent anticonflict effect in a modified Vogel's conflict test. The behavioral data further indicated that noradrenergic and serotonergic neurons as well as the benzodiazepine (BDZ) receptor may be involved in the anticonflict effect of yohimbine. In the present study the effects on rat brain monoamine neurochemistry and GABAA/BDZ receptor function (36Cl-uptake in corticohippocampal synaptoneurosomes) of a maximally anticonflict producing dose of yohimbine (4.0 mg/kg, i.p.) were studied. The levels of rat brain catecholamines and indoleamines were measured ex vivo using high performance liquid chromatography with electrochemical detection (HPLC-ED). Yohimbine decreased noradrenaline levels both in the hippocampus and the hemispheres but instead increased DOPAC levels in these brain regions as well as in the limbic forebrain. Yohimbine also markedly enhanced DOPA accumulation in the hippocampus and the hemispheres after inhibition of 1-aromatic amino acid decarboxylase by means of NSD 1015, whereas in the limbic system only a modest increase was obtained. The yohimbine-induced effects on the catecholamine synthesis rate were largely abolished in animals severely depleted of NA by means of 6-hydroxy-dopamine (6-OH-DA) pretreatment. Yohimbine decreased both the 5-HIAA/5-HT quotient (an indicator of 5-HT turnover) and 5-HTP accumulation after NSD 1015 in the hemispheres, whereas in the hippocampus and the limbic system only 5-HTP accumulation was decreased. The yohimbine-induced effect on the indoleamine synthesis rate was not influenced by 6-OH-DA pretreatment, whereas this effect and that on the catecholamine synthesis rate were both abolished by reserpine pretreatment. Neither in vivo nor in vitro administration of yohimbine significantly altered baseline or GABA-induced accumulation of 36Cl- in corticohippocampal synaptoneurosomes. In conclusion, the present study provides neurochemical support for the suggestion that yohimbine may exert its anticonflict effect in a modified Vogel's conflict test by increasing and decreasing NA and 5-HT neurotransmission, respectively, whereas no evidence was obtained for a direct interaction of yohimbine with GABAA/BDZ receptor function.

Citing Articles

Basal cortisol level modulates stress-induced opioid-seeking behavior.

Greenwald M, Woodcock E, Moses T, Lundahl L Neurobiol Stress. 2024; 33:100684.

PMID: 39524933 PMC: 11550728. DOI: 10.1016/j.ynstr.2024.100684.

Anti-stress neuropharmacological mechanisms and targets for addiction treatment: A translational framework.

Greenwald M Neurobiol Stress. 2018; 9:84-104.

PMID: 30238023 PMC: 6138948. DOI: 10.1016/j.ynstr.2018.08.003.

The yohimbine-induced anticonflict effect in the rat, Part I. Involvement of noradrenergic, serotonergic and endozepinergic(?) mechanisms.

Soderpalm A, BLOMQVIST O, Soderpalm B J Neural Transm Gen Sect. 1995; 100(3):175-89.

PMID: 8748665 DOI: 10.1007/BF01276457.

References

Jonsson G . Chemical neurotoxins as denervation tools in neurobiology. Annu Rev Neurosci. 1980; 3:169-87. DOI: 10.1146/annurev.ne.03.030180.001125. View

Feuerstein T, Mutschler A, Lupp A, Van Velthoven V, Schlicker E, Gothert M . Endogenous noradrenaline activates alpha 2-adrenoceptors on serotonergic nerve endings in human and rat neocortex. J Neurochem. 1993; 61(2):474-80. DOI: 10.1111/j.1471-4159.1993.tb02148.x. View

Ferre S, Artigas F . Dopamine D2 receptor-mediated regulation of serotonin extracellular concentration in the dorsal raphe nucleus of freely moving rats. J Neurochem. 1993; 61(2):772-5. DOI: 10.1111/j.1471-4159.1993.tb02187.x. View

Carlsson A, Lindqvist M . Effect of ethanol on the hydroxylation of tyrosine and tryptophan in rat brain in vivo. J Pharm Pharmacol. 1973; 25(6):437-40. DOI: 10.1111/j.2042-7158.1973.tb09129.x. View

Yu O, Chiu T, Rosenberg H . Modulation of GABA-gated chloride ion flux in rat brain by acute and chronic benzodiazepine administration. J Pharmacol Exp Ther. 1988; 246(1):107-13. View

Hjorth S, Magnusson T . The 5-HT 1A receptor agonist, 8-OH-DPAT, preferentially activates cell body 5-HT autoreceptors in rat brain in vivo. Naunyn Schmiedebergs Arch Pharmacol. 1988; 338(5):463-71. DOI: 10.1007/BF00179315. View

Hokfelt T, Johansson O, Fuxe K, Goldstein M, Park D . Immunohistochemical studies on the localization and distribution of monoamine neuron systems in the rat brain. I. Tyrosine hydroxylase in the mes- and diencephalon. Med Biol. 1976; 54(6):427-53. View

Mitchell S . Role of the locus coeruleus in the noradrenergic response to a systemic administration of nicotine. Neuropharmacology. 1993; 32(10):937-49. DOI: 10.1016/0028-3908(93)90058-b. View

Soderpalm B, Andersson G, Johannessen K, Engel J . Intracerebroventricular 5,7-DHT alters the in vitro function of rat cortical GABAA/benzodiazepine chloride ionophore receptor complexes. Life Sci. 1992; 51(5):327-35. DOI: 10.1016/0024-3205(92)90584-c. View

10.

PAPESCHI R, Theiss P . The effect of yohimbine on the turnover of brain catecholamines and serotonin. Eur J Pharmacol. 1975; 33(1):1-12. DOI: 10.1016/0014-2999(75)90131-4. View

11.

Waterhouse B, Moises H, Woodward D . Interaction of serotonin with somatosensory cortical neuronal responses to afferent synaptic inputs and putative neurotransmitters. Brain Res Bull. 1986; 17(4):507-18. DOI: 10.1016/0361-9230(86)90218-2. View

12.

Goldberg M, Robertson D . Yohimbine: a pharmacological probe for study of the alpha 2-adrenoreceptor. Pharmacol Rev. 1983; 35(3):143-80. View

13.

Baraban J, Wang R, AGHAJANIAN G . Reserpine suppression of dorsal raphe neuronal firing: mediation by adrenergic system. Eur J Pharmacol. 1978; 52(1):27-36. DOI: 10.1016/0014-2999(78)90018-3. View

14.

Baraban J, Aghajanian G . Suppression of serotonergic neuronal firing by alpha-adrenoceptor antagonists: evidence against GABA mediation. Eur J Pharmacol. 1980; 66(4):287-94. DOI: 10.1016/0014-2999(80)90461-6. View

15.

Ehrenstrom F, Johansson P . A method for very rapid determinations of catechols using ion-pairing reverse phase HPLC with electrochemical detection: effects of L-dopa treatment on the catechol content in various rat brain structures. Life Sci. 1985; 36(9):867-79. DOI: 10.1016/0024-3205(85)90211-5. View

16.

Sharp T, Bramwell S, Grahame-Smith D . 5-HT1 agonists reduce 5-hydroxytryptamine release in rat hippocampus in vivo as determined by brain microdialysis. Br J Pharmacol. 1989; 96(2):283-90. PMC: 1854361. DOI: 10.1111/j.1476-5381.1989.tb11815.x. View

17.

Schwartz R, Jackson J, Weigert D, Skolnick P, Paul S . Characterization of barbiturate-stimulated chloride efflux from rat brain synaptoneurosomes. J Neurosci. 1985; 5(11):2963-70. PMC: 6565157. View

18.

Soderpalm A, BLOMQVIST O, Soderpalm B . The yohimbine-induced anticonflict effect in the rat, Part I. Involvement of noradrenergic, serotonergic and endozepinergic(?) mechanisms. J Neural Transm Gen Sect. 1995; 100(3):175-89. DOI: 10.1007/BF01276457. View

19.

Woodward D, Moises H, Waterhouse B, Hoffer B, Freedman R . Modulatory actions of norepinephrine in the central nervous system. Fed Proc. 1979; 38(7):2109-16. View

20.

Gallager D, Aghajanian G . Effect of antipsychotic drugs on the firing of dorsal raphe cells. I. Role of adrenergic system. Eur J Pharmacol. 1976; 39(2):341-55. DOI: 10.1016/0014-2999(76)90144-8. View