Central TRH receptor 1 antisense blocks cold-induced gastric emptying but not brain c-Fos induction

We studied whether TRH receptor I (TRH-R1) antisense oligodeoxynucleotides injected intracisternally, impaired acute cold-induced c-Fos expression in the brain and vagally mediated stimulation of gastric emptying in conscious rats. Cold exposure (4-6 degreesC, 90 min) increased gastric emptying and the number of c-Fos positive cells in the paraventricular nucleus of the hy pothalamus, supraoptic nucleus, raphe pallidus, dorsal motor nucleus of the vagus, nucleus of the solitary tract and area postrema compared with rats at room temperature. TRH-R1 antisense abolished cold-induced stimulation of gastric transit but not c-Fos expression in the brain. TRH-RI mismatch did not alter the gastric response to cold. These data indicate that central a ctivation of TRH-RI mediates cold-induced stimulation of gastric emptying b ut does not influence the induction of c-Fos expression in the brain. (C) 2 001 Elsevier Science Inc. All rights reserved.