As reported in Sciencemag.org the fields of artificial intelligence and optogenetics are helping scientists to map the brain of a fruit fly (drosophila melanogaster). The research is being conducted at the Janelia Research Campus is part of the Howard Hughes Medical Institute in Ashburn , Virginia , USA .The website states that Janelia’s philosophy is ‘bold, risky science is encouraged?’ .
Fruit flies are known as Model organisms and particularly useful in genetic studies as they have a very short life span , this enables a multi-generation study in a relatively short time span , known as epigenetics . Fruit flies also share a large portion of their D.N.A with humans , the D.N.A match between humans & the fruit fly is thought to be around 60% , with much of the match being homeotic or ‘master’ gene types . This makes the fruit fly a good candidate for genetic studies which can be applied to us humans , so good in fact that the fruit fly has been rocketed to the International Space Station on NASA sponsored experiments .
“Lord of the Flies”
The research is focused on mapping the fruit fly brain & nervous system and the corresponding links to various behavioural patterns . This includes all of the usual bahaviour traits seen in the life of typical fruit fly such as walking , sex , feeding , flying & escaping predators , plus many more individual neuronal responses that indicate less overt characteristics . Around 20,000 videos have so far been uploaded by the research team , each one relating to a separate fruit fly movement or response .
CaMPARI (Calcium Modulated Photoactivatable Ratiometric Integrator) is the system being used to actually map the neuronal activity of the fly . The system involves modifying the brain cells of a fruit fly so that they fluoresce when exposed to ‘light’ , the ‘light’ could in theory be any electro-magnetic wavelength that excites the modified brain cells but is usually infrared light or similar . The genetically modified protein is first bonded to a calcium sensor gene , this is then encoded in the fruit flies own D.N.A , the modified D.N.A is reproduced in the fruit flies brain & passed on to any offspring .
Like most animal species each and every action or reaction of the fruit fly will produce a neuronal response , the neuronal pattern will be unique to each specific action . One of the first steps in brain body communication involves calcium signaling , a specific set of neurons are ‘flooded’ with calcium ions when invoked , this signal passes to other adjacent cells as part of the whole electrochemical brain response . The newly introduced modified gene will fluoresce as the calcium floods into the brain cell , thus creating a pattern of brain cell activity that corresponds to the particular action of the fruit fly . In the case of the fruit fly the cell fluorescence is this study is permanent , allowing the researchers time to study the brain pattern , in other experiments involving a similar process the fluorescence soon dampens .
The research team uses what they have termed genetically encoded calcium indicators (GECI’s) , basically a derivative of a green fluorescent protein . Green fluorescent proteins are found in many species of sea life but the the original GFP was was first extracted from a jellyfish , this original protein has since been further modified into several variants . Other fluorescent proteins are found in bacteria , specifically the small ultra red fluorescent protein (smURFP) which was cultivated from Cyanobacteria . Variants of the smURFP protein have been evolved which can covalently bond to biliverdin which is formed in the human body when red blood cells break down .
The team used an open source computer program called JAABA – Janelia Automatic Animal Behavior Annotator . The program was used to film the movements of the fly & mark out the corresponding brain patterns . In this instance the program carried out tasks what would have taken a human years . Theoretically the information gleaned from JAABA could be reverse engineered to actually form a working virtual image of the brain of a fruit fly , such a system could further be ‘trained’ to control a fruit fly also by reversing the measurement system which is termed Adaptive Optics . Instead of measuring the brain response , the exact same signals could be ‘beamed’ at a fruit fly to provoke a neural response , a response that could for example make the fly move backwards .
Of course , this is just theoretical , besides which there is no real motive to control a group of humble fruit flies , is there ?
- Artificial Intelligence Helps Build Brain Atlas of Fly Behavior
- Adaptive Optics
- GAL4 Fly Lines
Also related :
- Green fluorescent protein
- smURFP expressed in vivo and smURFP fusions in mammalian cells
- Ultrasensitive Calcium Sensors Shine New Light on Neuron Activity
- Fluorescent protein-based calcium integrators (patent)
- Calcium Indicators Based on Calmodulin–Fluorescent Protein Fusions
- Genetically-Encoded Calcium Indicators
- Measurement of Intracellular Calcium