Effect of short- and long-term morphine treatment on gene expression in the hypothalamus and pituitary

ABSTRACT: Addictive drugs including opioids activate signal transduction pathways that regulate gene expression in the brain. However, changes in CNS gene expression following morphine exposure are poorly understood. We studied the effect of short- and long-term morphine treatment on gene expression in the hypothalamus and pituitary using genome-wide DNA microarray and real-time reverse transcriptase polymerase chain reaction (RT-PCR) analyses. In the hypothalamus, we found that short-term morphine administration up-regulated (at least 2-fold) 39 genes and down-regulated six genes. Long-term morphine administration up-regulated 35 genes and down-regulated 51 hypothalamic genes. In the pituitary, we found that short-term morphine administration up-regulated (at least 2-fold) 110 genes and down-regulated 29 genes. Long-term morphine administration up-regulated 85 genes and down-regulated 37 pituitary genes. Strikingly, microarray analysis uncovered several genes involved in food intake (neuropeptide Y, agouti-related protein, and cocaine and amphetamine-regulated transcript) whose expression was strongly altered by morphine exposure in either the hypothalamus or pituitary. Subsequent RT-PCR analysis confirmed similar gene regulation of noteworthy genes in these regions. Finally, we found functional correlation between morphine-induced alterations in food intake and regulations of genes involved in this process. Changes in genes related to food intake may uncover new pathways related to some of the physiological effects of opioids. Keywords: Comparative treatment versus placebo

ORGANISM(S): Mus musculus

PROVIDER: GSE9525 | GEO | 2008/10/01

SECONDARY ACCESSION(S): PRJNA103333

REPOSITORIES: GEO