as maylong talke about, dopa mine is important in parkinson's disease so we can express that gene inhe neurones. so the top panel shows clusters of dopaminerjic, we see fewer of those cells staining for this neuron for dopaminergic neurones. if we express in those cells, theybecome compromised and sick and by expressing this gene associated with human's parkinson's disease we can get effects in the fly that look like core effects of parkinson's disease. i would like to show another example that's showing an effect on climbing behavior. so this is using a gene in the fly that's involved in a.l.s., so a.l.s. is another -- >> amyo trophic lateral sclerosis. lou gehrig's disease. it' anherery debilitating disease and leads to loss of voluntary movement control and total paralysis. if we look at the behavior of normal flies, normal flies will climb upwards. they have this robust negative geotactic response, but the flies that are defective in this human a.l.s. gene, these flies are alive and they are moving but they can no longer climb, so this is a remarkable example of sort of a fundame