Mosquito Brain (IMAGE) Virginia Tech Caption This picture of a mosquito brain highlights the presence of dopamine in regions involved in the sense of smell. The purple areas indicate tyrosine hydroxylase, which is the precursor of dopamine. Credit Photo courtesy of Gabriella Wolff Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.