Fig. 1

Effects of intra-VTA infusion of adiponectin and AdipoRon on dopamine neuron activity. (a) In situ hybridization showing expression patterns of AdipoR1 and AdipoR2 mRNA in the VTA (left) and colocalization of AdipoR1 and tyrosine hydroxylase (TH) mRNA (right). (b) Schematic procedure of in vivo extracellular recording of dopamine neurons in the VTA. (c) Effects of intra-VTA vehicle injection. Top-left, representative extracellular voltage traces from identified dopamine neurons in the VTA; top-center, representative image demonstrating the electrode track through the VTA; top-right, number of spontaneously active dopamine neurons per track in the VTA. Middle-left, firing rate; middle-center, scatter plot distribution; middle-right, cumulative frequency distribution. Bottom-left, percent burst firing; bottom-center, scatter plot distribution; bottom-right, cumulative frequency distribution. 1st vehicle: n = 7 mice; 2nd vehicle: n = 7 mice. (d) Effects of intra-VTA adiponectin injection. Top-left, representative extracellular voltage traces from VTA dopamine neurons; top-center, representative image demonstrating the electrode track through the VTA; top-right, number of spontaneously active dopamine neurons per track in the VTA. Middle-left, firing rate; middle-center, scatter plot distribution; middle-right, cumulative frequency distribution. Bottom-left, percent burst firing; bottom-center, scatter plot distribution; bottom-right, cumulative frequency distribution. *P < 0.05, **P < 0.01 compare with the vehicle-treated control group. Vehicle: n = 7 mice; adiponectin: n = 7 mice. (e) Effects of intra-VTA AdipoRon injection. Top-left, representative extracellular voltage traces from VTA dopamine neurons; top-center, representative image demonstrating the electrode track through the VTA; top-right, number of spontaneously active dopamine neurons per track in the VTA. Middle-left, firing rate; middle-center, scatter plot distribution; middle-right, cumulative frequency distribution. Bottom-left, percent burst firing; bottom-center, scatter plot distribution; bottom-right, cumulative frequency distribution. *P < 0.05, **P < 0.01 compare with the vehicle-treated group. Vehicle 1: n = 8 mice; AdipoRon 0.1 nmol: n = 8 mice; Vehicle 2: n = 8 mice; AdipoRon 1.0 nmol: n = 8 mice. VTA ventral tegmental area