pC1 and P1 neurons
systemCourtshipspeciesD. melanogaster3D view1 of 626 cellssources5
pC1 is a cluster of neurons in the fruit fly brain that express the sex-determination gene doublesex. In males it includes the P1 neurons, a male-specific group that can initiate courtship and that sets the male’s state of courtship arousal.
| Also known as | P1 neurons · pC1 cluster · doublesex-expressing pC1 neurons |
|---|---|
| Region | Dorsal posterior central brain near the mushroom body, branching in both hemispheres |
| System | Courtship |
| In the display bundle | 1 of the 626 reconstructed neurons in the site’s MaleCNS display bundle, which shows 626 of the model’s 166,700 neurons: pC1_14a 1 |
What they are
P1 is a male-specific cluster of about 20 interneurons that express both fruitless and doublesex. It lies in the dorsal posterior brain near the mushroom body, and each neuron has a main neurite that crosses the midline and branches extensively in the protocerebrum of both hemispheres. In females these cells die through the action of the female form of the Doublesex protein (Kimura et al., 2008).
P1 neurons lie within the larger doublesex-expressing pC1 cluster, part of which is also present in females (Robinett et al., 2010). The MaleCNS names the cluster’s cells as numbered subtypes, such as pC1_14a.
What they do
Inducing a P1 clone in females provokes male-typical behavior even when the rest of the brain is not masculinized (Kimura et al., 2008). In males, the initiation of courtship correlates with activation of P1 neurons, and P1 neurites show a calcium rise when the male’s foreleg touches a female’s abdomen (Kohatsu et al., 2011).
P1 and the descending pIP10 neurons mediate the decision to sing courtship song, while thoracic neurons pattern the song (von Philipsborn et al., 2011).
Courtship state
P1 activity sets a lasting state of arousal. During courtship it increases the gain of LC10a visual neurons, and fluctuations in P1 activity track the intensity of the male’s pursuit (Hindmarsh Sten et al., 2021).