A) We were able to develop a method to optically activate two populations of neurons, at the cell body, independently. This is based on the co-expression of a red-shifted ChR2 (Chrimson) and a chloride channel (GtACR2). We tested the system, in drosophila, and it has been remarkably successful in drosophila; only a red-light, and not blue light, is able to activate the circuit in this system. We also tested this method in organotypic brain slices with equally successful result. The next step is to apply our method in behaving rodents. B) We used red-shifted ChR2 with a chemogenetic system, known as DREAD. In organotypic brain, we were able to effectively block the blue-induced activation of the neurons co-expressing red-shifted ChR2 and hM4D(Gi) (the receptor used in DREAD system). We have used this system in vivo with a comparable efficiency. In a collaboration with our colleagues at NIH, we included a part of in vivo data in a manuscript that is now under review. as and C) We were able to generate an optically induced weak fear memory in mice that lasts 15-30 minutes but not 24 hrs. To our best knowledge, there is no published work demonstrating induction of a fear weak memory, which last only for about 30min. Fear memory as we are all aware is a memory that is very difficult to forget. So, it is no surprise that making a fear memory that last only for a couple of minutes has been a challenge, which I believe that we overcome. D) We have shown that we can label newly synthesized proteins in vivo with L-azidohomoalaine amino acid. With this system, we were able to purify newly synthesized proteins from synaptic preparations. We were able to label newly synthesized proteins, in vivo as well. This is done by supplementing L-azidohomoalaine amino acid in animals diet. The next step is to induce a protein-synthesis dependent LTP in anesthetized animals that are fed with this diet and send the protein preps to the lab of Dr. Yates at the university of California, San Diego for mass spectrometry analysis. E) We developed a photoactivatable unnatural amino acid. This is to identify newly synthesized proteins that are believed to be essential for the stabilization of a memory. Currently, we are working to improve this system for the use in in vivo studies.
