Analyzing the Prey-Evoked Neuronal Activity in a Transgenic Zebrafish Larva
Transcript
Begin with a behavior recording chamber containing an anesthetized, transgenic zebrafish larva immobilized in a low-melting agarose.
The larva's midbrain pretectum region and the inferior lobe of the hypothalamus contain modified neurons expressing fluorescent calcium indicators.
Remove the agarose around the larva's head and wash with water to remove any residual agarose.
Place a paramecium as prey near the larva.
Transfer the recording chamber under a fluorescence microscope.
As the prey swims, the larva's eye detects it and sends a signal to the pretectum and hypothalamus regions involved in prey detection.
This opens calcium channels in these neurons, allowing calcium ions to enter and bind to the calcium indicators, leading to fluorescence emission.
Record the time-lapse imaging to detect the fluorescence intensity from neurons along the prey's swimming path and generate a color map.
In this map, arrowheads represent prey trajectories: black arrows show no neuronal excitation, while colored arrows indicate increased neuronal excitation triggered by the prey's movement.
