EVIDENCE FOR THE PRESENCE OF BETA-3-ADRENERGIC RECEPTOR MESSENGER-RNAIN THE HUMAN BRAIN

The beta 3-adrenergic receptor (AR) is widely distributed in periphera l tissues, but up to now it has not been detected in the central nervo us system. By using the polymerase chain reaction (PCR) technique, we found the beta 3-AR mRNA to be present in all the regions of the human brain we investigated. The quantities found were very low compared to those of the beta 1-AR and beta 2-AR mRNAs, being hardly detectable i n adult brain. In contrast, the brain of very young infants contained about 100 times more beta 3-AR mRNA than the adult brain, whereas the amounts of beta 1-AR and beta 2-AR transcripts were essentially the sa me. In addition, using PCR we have cloned a central beta 3-AR coding r egion from a human frontal cortex cDNA library and have found it to be identical to the corresponding peripheral sequence.