Intersectional expression of Foxp2 and Grp identifies cold-activated parabrachial neurons.

The parabrachial nucleus (PB) contains many neuronal subpopulations, including a cold-activated subset that relays thermosensory information to the forebrain. Although these neurons are part of the Atoh1-derived PB macropopulation, their precise genetic identity has remained unclear, limiting cell-type-specific investigation of cold-defense circuitry. In this study, we show that this subpopulation is selectively identified by coexpression of Foxp2 and Grp. This intersectional molecular identity suggests a practical strategy for selectively targeting cold-activated PB neurons, enabling cell-type-specific dissection of the circuit mechanisms underlying autonomic and behavioral cold-defense responses.NEW & NOTEWORTHY Cold-activated neurons in the PB relay thermosensory signals that drive autonomic and behavioral cold-defense responses, but their molecular identity has remained unclear. Here, we show that these neurons are selectively identified by coexpression of Foxp2 and Grp, a combination that distinguishes them from surrounding PB neurons. This intersectional genetic identity provides a practical strategy for selectively targeting this population, enabling future mechanistic studies of thermoregulatory circuits.