Definiranje karakteristika metamfetamin ovisnog oscilatora u D. melanogaster

Krajem prošlog stoljeća uočeno je da administracija metamfetamina (METH) putem vode za piće izaziva pojavu ritmičnosti kod aritmičnih ţivotinja. Ova pojava ukazuje na prisustvo jedinstvenog cirkadijalnog oscilatora ovisnog o metamfetaminu (MASCO), ali ne i o glavnom cirkadijalnom molekularnom mehanizmu. Iako je od prvog opisa MASCO-a , pa sve do danas provedeno niz eksperimenta na različitim skupinama ţivotinja, anatomska lokacija i točan mehanizam organizacije MASCO-a još uvijek nisu poznati. U dosadašnjim eksperimentima za istraţivanje MASCO-a kao modelni organizmi najviše su korišteni miševi i štakori, no korištenje Vinske mušice (Drosophila melanogaster) uvelike bi olakšalo provedbu eksperimenta zbog jednostavnijeg ţivčanog sustava, lakše genetske manipulacije, kraćeg ţivotnog vijeka i jeftinijeg uzgoja. U našim eksperimentima proučavan je utjecaj METH-a na ritmičnost mušica, i ispitivanje osnovnih karakteristika MASCO-a. U eksperimentu su korištene mušice divljeg tipa (wt), one s nul mutacijom u dopaminskom transporteru, fumin (fmn) i s nul mutacijom u jednom od glavnih cirkadijalnih gena, period (per01). Lokomotorna aktivnost je najprije mjerena u uvjetima 12 sati svijetla i 12 sati mraka (LD) na standardnoj hrani, a zatim 16 dana u konstantnom mraku (DD) dok su tretirane s 10 μg/mL METH-a. Dobiveni rezultati nisu uspjeli potvrditi postavljene hipoteze da će prisutnost MASCO-a biti vidljiva u promjeni duţine perioda lokomotorne aktivnosti ili u promjeni jačine ritma lokomotorne aktivnosti. Utjecaj tretmana METH-om bio je sličan u wt, fmn i per01 mušica. Buduća istraţivanja u bolje kontroliranim uvjetima mogla bi doprinjeti boljem razumijevanju utjecaja METH-a i cirkadijalnih gena na ritmičnu lokomotornu aktivnost.At the end of the last century it has been noticed that administration of metamphetamine (METH) in drinking water caused rhythmic behavior in arhytmic animals. This phenomenon indicates the presence of a specific metamphetamine sensitive circadian oscillator (MASCO), that is main circadian molecular mechanism independent. Even though many experiments had been conducted since the discovery of MASCO, the right anatomic location and molecular organisation of MASCO remains unknown. In those experiments mice and rats were generally used. Usage of fruit fly (D.melanogaster) would largely improve counduction of experiments because of their simpler nervous system, easier genetic manipulations, short life duration and lower costs. The main focus of our experiments was the effect of METH on the rythmicity of the flies and on defining the characteristics of MASCO. We used the wild type of flies (wt), flies with a null mutation in dopamine transporter, fumin (fmn) and flies with a null mutation in one of the main circadian genes, period (per01). The fly's locomotor activity was first measured in 12 hours light and 12 hours darkness (LD) on standard food and then, subsequently, 16 days in complete darkness (DD) while being treated with 10 μg/mL METH. Results of the experiments have failed to confirm the main hypotheses, which were that the presence of MASCO will manifest either in changing the length of the period or in changing the power of the rhythm of locomotor acitivity. Effect of the treatment with METH was alike in wt, fmn and per01 flies. Further experiments in more controlled conditions could lead to better understanding of effects of METH and ciracadian genes on rhythmic locomotor activity