Vectorology - GEG Tech top picks

Optogenetics may enable mutation-independent, circuit-specific restoration of neuronal function in neurological diseases. Retinitis pigmentosa is a neurodegenerative eye disease where loss of photoreceptors can lead to complete blindness. In a blind patient, the researchers combined intraocular injection of an adeno-associated viral vector encoding ChrimsonR with light stimulation via engineered goggles. 

Here, the scientists present a dual-protein switch system, Cal-Light, that translates neuronal-activity-mediated calcium signaling into gene expression in a light-dependent manner. In cultured neurons and brain slices, they show that Cal-Light drives expression of the reporter EGFP with high spatiotemporal resolution only in the presence of both blue light and calcium. Delivery of the Cal-Light components to the motor cortex of mice by viral vectors labels a subset of excitatory and inhibitory neurons related to learned lever-pressing behavior. By using Cal-Light to drive expression of the inhibitory receptor halorhodopsin (eNpHR), which responds to yellow light, we temporarily inhibit the lever-pressing behavior, confirming that the labeled neurons mediate the behavior. Thus, Cal-Light enables dissection of neural circuits underlying complex mammalian behaviors with high spatiotemporal precision.

Here, the scientists reveal a critical role for the central nucleus of the amygdala in predatory hunting. Both optogenetic and chemogenetic stimulation of central amygdala of mice elicited predatory-like attacks upon both insect and artificial prey.

Neurophysiological phenomena that underlie the symptoms of autism remain unclear. Genetics-based mouse models of autism have suggested that there is an increase in the neuronal excitation/inhibition (E:I) balance. An optogenetically driven increase in this E:I balance leads to social deficits in mice. Using mice lacking CNTNAP2 , a gene known to be associated with autism in humans, Selimbeyoglu and colleagues now show that real-time optogenetic modulation of the E:I balance rescued social behavior deficits and hyperactivity in these animals. This study highlights the potential for modulating neural circuits in the brain as a strategy for treating autism.

Researchers have identified two groups of neurons that can be turned on and off to alleviate the movement-related symptoms of Parkinson's disease. The activation of these cells in the basal ganglia relieves symptoms for much longer than current therapies, like deep brain stimulation and pharmaceuticals. The study, completed in a mouse model of Parkinson's, used optogenetics to better understand the neural circuitry involved in Parkinson's disease, and could provide the basis for new experimental treatment protocols.

Optogenetics is a new biological technique that allows reversible modulation of electrical function with unmatched spatiotemporal precision using light-gated ion channels. Here, the authors investigated optogenetic manipulation of anatomical re-entry in ventricular cardiac tissue.

Optogenetics is emerging in the cardiology field as a new strategy to explore biological functions through the use of light-sensitive proteins and dedicated light sources. For example, this technology allows modification of the electrophysiological properties of cardiac muscle cells with superb spatiotemporal resolution and quantitative control. In this chapter, the optogenetic modification of atrial cardiomyocytes (aCMCs) from 2-day-old Wistar rats using lentiviral vector (LV) technology and the subsequent activation of the light-sensitive proteins (i.e., ion channels) through light-emitting diodes (LEDs) are described.