Light and dopamine influence two daily rhythm neurons to support waking up in the morning

Single-cell sequencing identified 17 Drosophila circadian neuron groups, including two that express the neuropeptide ion transport peptide (ITP) and are crucial for morning activity.

• Inhibiting the two ITP-expressing lateral neurons significantly reduces morning activity in Drosophila.
• These neurons express higher levels of the type 1-like dopamine receptor Dop1R1 compared to other lateral neurons.
• Mutating Dop1R1 in the two ITP neurons leads to significantly decreased morning activity.
• Dop1R1 activation in these neurons shows stronger responses to dopamine in the morning than at other times.
• Morning levels of Dop1R1 mRNA are higher and are influenced by light exposure.

Simplified