Resources
Authors & Affiliations
Kevin Haselhuhn, John Tuff, Marie Ziegler, Onur Güntürkün, Noemi Rook
Abstract
Birds are excellent models to study learning, complex cognition, song and vision. However, to understand how these behaviors are realized within the brain, methods that are able to record and control cellular activity on a millisecond timescale are essential. Recent advancements in novel methods, such as optogenetics, calcium imaging or DREADDs, have revolutionized rodent research, but are not yet widely used in avian research. This is in part due to the fact that these methods rely on the introduction of genetic information for artificial ion channels or sensors. In the absence of transgenic animals, adeno-associated viruses (AAVs) are often used for viral gene transfer. AAVs can be flexibly implemented to transfer different genetic sequences as well as to achieve cell-type specificity or conditional gene expression through distinct promoter systems. While AAVs have been used in pigeons before, this study set out to verify further tools to gain specific gene expression. We provide a proof of concept that GCaMP7 and NpHR can successfully be expressed in pigeon neurons. Furthermore, we are able to show that CaMKII and mDLX promoters lead to cell-type specific expression. Likewise, this study offers a proof of concept for the functionality of the Cre/loxP and a Tet-On/Tet-Off system. While Cre/loxP expands the possibility to transfer genes that are too large for typical AAVs, the Tet-On/Tet-Off system offers conditional gene expression. These novel tools open new avenues for behavioral research in pigeons to understand the avian brain.