PT  - JOURNAL ARTICLE
AU  - Bachtell, Ryan K.
AU  - Tsivkovskaia, Natalia O.
AU  - Ryabinin, Andrey E.
TI  - Alcohol-Induced c-Fos Expression in the Edinger-Westphal Nucleus: Pharmacological and Signal Transduction Mechanisms
AID  - 10.1124/jpet.102.036046
DP  - 2002 Aug 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 516--524
VI  - 302
IP  - 2
4099  - http://jpet.aspetjournals.org/content/302/2/516.short
4100  - http://jpet.aspetjournals.org/content/302/2/516.full
SO  - J Pharmacol Exp Ther2002 Aug 01; 302
AB  - Mapping inducible transcription factors has shown that the Edinger-Westphal nucleus is preferentially sensitive to alcohol intoxication. Herein, we characterize the pharmacological and signal transduction mechanisms related to alcohol-induced c-Fos expression in Edinger-Westphal neurons. Using immunohistochemistry, we show that pretreatment with γ-aminobutyric acid (GABA)-ergic antagonists (4 mg/kg bicuculline and 45 mg/kg pentylenetetrazole) attenuates induction of c-Fos expression by alcohol (2.4 g/kg, intraperitoneal). In addition, 10 mg/kg 2-(2,3-dihydro-2-methoxy-1,4-benzodioxin-2-yl)4,5-dihydro-1H-imidazole (RX 821002), an α2A/D-adrenoceptor antagonist, and 20 mg/kg haloperidol, a dopamine antagonist, also block alcohol-induced c-Fos expression in Edinger-Westphal neurons. No effects were seen in alcohol-induced c-Fos after the pretreatment of 20 mg/kg propranolol (β-adrenoceptor antagonist), 10 mg/kg 2-(2-(4-(2-methoxyphenyl)piperazin-1-yl) ethy)-4,4-dimethyl-1,3-(2H,4H)-isoquinolindione dihydrochloride (ARC 239) (α2B/C-adrenoceptor antagonist), or 30 mg/kg naltrexone (opioid antagonist). Although positive modulators for the GABAA receptor (20 mg/kg 3α-hydroxy-5α-pregnan-20-one and 10–30 mg/kg chlordiazepoxide) and opioid receptor (10 mg/kg morphine) produced significant elevations, agonists for α2-adrenoceptors (clonidine) and dopamine receptors (apomorphine) had no effect on Edinger-Westphal c-Fos expression. These findings suggest that alcohol-induced c-Fos expression in Edinger-Westphal results from direct interactions with GABAA receptors, which are modified by α2A/D-adrenoceptors and dopamine receptors. Also using immunohistochemistry to identify potential intracellular mechanisms associated with alcohol-induced c-Fos expression in Edinger-Westphal, we show time-dependent increases in serine 727 phospho-signal transducer and activator of transcription 3 (Stat3) but no changes in phospho-cAMP response element-binding protein and phospho-Elk1. Time-dependent increases in phospho-extracellular signal-regulated kinase (ERK) 1/2 were found to occur simultaneously with increases in serine 727 phospho-Stat3. Finally, blockade of ERK 1/2 phosphorylation with the mitogen-activated protein kinase (MEK) 1/2 inhibitor SL327 blocked alcohol-induced c-Fos expression, suggesting that alcohol induces c-Fos in Edinger-Westphal neurons through activation of the MEK1/2-ERK1/2-Stat3 pathway. The American Society for Pharmacology and Experimental Therapeutics