Optogenetic Manipulation of Selective Neural Activity in Free-Moving Drosophila Adults

Abstract

Activating selected neurons elicits specific behaviors in Drosophila adults. By combining optogenetics and laser-tracking techniques, we have recently developed an automated laser-tracking and optogenetic manipulation system (ALTOMS) for studying how brain circuits orchestrate complex behaviors. The established ALTOMS can independently target three lasers (473-nm blue laser, 593.5-nm yellow laser, and 1064-nm infrared laser) on any specified body part of two freely moving flies. Triggering light-sensitive proteins in real time, the blue laser and yellow laser can respectively activate and inhibit target neurons in artificial transgenic flies. Since infrared light is invisible to flies, we use the 1064-nm laser as an aversive stimulus in operant learning without perturbing visual inputs. Herein, we provide a detailed protocol for the construction of ALTOMS and optogenetic manipulation of target neurons in Drosophila adults during social interactions.

The Roles of Optogenetics and Technology in Neurobiology: A Review

“…But through optogenetics, scientists are unraveling the mysteries of biological social behavior. Chiang and his colleagues developed an automatic laser tracking and optogenetic manipulation system ( Hsiao et al, 1408 ; Wu et al, 2014 ) (ALTOMS) that can be used to study the social memory of fruit flies. After the expression of photosensitive proteins in neurons at specific sites, neurons involved in pain expression photosensitive pathways can be activated when laser irradiation is applied to specific sites ( Karim et al, 2006 ; Table 1 and Figure 2 ).…”

“…Using the system, the researchers were able to get certain males to quickly learn to avoid females, while other males continued to approach. At the same time, automated laser tracking and optogenetic manipulation systems (ALTOMS) ( Hsiao et al, 1408 ; Wu et al, 2014 ) are expected to help identify the neural circuits responsible for specific drosophila behavior and understand the circuitry behind the ability to form memories based on social interaction learning.…”

3D reconstruction of cell nuclei in a full Drosophila brain

“…Although Drosophila melanogaster is an important model organism, its brain cell number is still uncertain. Earlier accounts of the number of neurons in the adult fly brain (Alivisatos et al, 2012;Hsiao et al, 2016;Kaiser, 2015) (Chiang et al, 2011;Simpson, 2009) were anecdotal. The first published estimates of Drosophila brain cell number appeared earlier this year.…”