Figure 2

Reduced exercise capacity in conditions of pF_RTN/C1 inhibition in rats. (A, B) Histological analysis of virally-induced HM₄DR expression in the parafacial region of the rostral ventrolateral medulla oblongata. (A) Neurons transduced to express HM₄DR (identified by mCitrine immunoreactivity, green) are concentrated medial and ventral to the facial nucleus, identified by ChAT immunostaining (red). (B) Neurons transduced to express HM₄DR/ mCitrine (green), are interspearsed with catecholaminergic C1 neurons (identified by TH immunoreactivity, red). A proportion of C1 neurons were found to be transduced (yellow: arrows). Anatomical landmarks (dashed white lines) are shown to aid illustration of the injection sites, 7n – facial nucleus, Py – pyramidal tract, SP-5 – spinal trigeminal tract. (Ci) Exercise capacity is unaffected by CNO (2 mg·kg⁻¹) in rats transduced to express eGFP by the pF_RTN/C1 neurons; (Cii) Exercise capacity is markedly reduced by CNO (2 mg·kg⁻¹) in rats transduced to express HM₄DR by the pF_RTN/C1 neurons.