Infrared (top) and fluorescence (bottom) imaging of serotonin (5-HT) neurons in the dorsal raphe of Pet1-cre/mCherry miceCurrent-clamp electrical recording of a NPY-GFP neuron in response to variations in glucose concentration.Voltage-clamp electrical recording of spontaneous GABA inhibitory currents on dorsal raphe 5-HT neurons in response to insulinOptogenetic stimulation of POMC neurons in the arcuate nucleus of POMC-cre mice injected with AAV-flex-hCHR2-mCherryElectrophysiological recording of a striatal middle spiny neuron in mice. A, Electrophysiological profile of the neuron following injection of current jumps (10 pA increment). B, Synaptic response of the neuron following stimulation of glutamatergic afferents (2 stimulations at 50 ms intervals).