The coding of cutaneous temperature in the spinal cord.
2016; 19 (9): 1201-1209
The spinal cord is the initial stage that integrates temperature information from peripheral inputs. Here we used molecular genetics and in vivo calcium imaging to investigate the coding of cutaneous temperature in the spinal cord in mice. We found that heating or cooling the skin evoked robust calcium responses in spinal neurons, and their activation threshold temperatures distributed smoothly over the entire range of stimulation temperatures. Once activated, heat-responding neurons encoded the absolute skin temperature without adaptation and received major inputs from transient receptor potential (TRP) channel V1 (TRPV1)-positive dorsal root ganglion (DRG) neurons. By contrast, cold-responding neurons rapidly adapted to ambient temperature and selectively encoded temperature changes. These neurons received TRP channel M8 (TRPM8)-positive DRG inputs as well as novel TRPV1(+) DRG inputs that were selectively activated by intense cooling. Our results provide a comprehensive examination of the temperature representation in the spinal cord and reveal fundamental differences in the coding of heat and cold.
View details for DOI 10.1038/nn.4350
View details for PubMedID 27455110
Input-specific control of reward and aversion in the ventral tegmental area
2012; 491 (7423): 212-?
Ventral tegmental area (VTA) dopamine neurons have important roles in adaptive and pathological brain functions related to reward and motivation. However, it is unknown whether subpopulations of VTA dopamine neurons participate in distinct circuits that encode different motivational signatures, and whether inputs to the VTA differentially modulate such circuits. Here we show that, because of differences in synaptic connectivity, activation of inputs to the VTA from the laterodorsal tegmentum and the lateral habenula elicit reward and aversion in mice, respectively. Laterodorsal tegmentum neurons preferentially synapse on dopamine neurons projecting to the nucleus accumbens lateral shell, whereas lateral habenula neurons synapse primarily on dopamine neurons projecting to the medial prefrontal cortex as well as on GABAergic (γ-aminobutyric-acid-containing) neurons in the rostromedial tegmental nucleus. These results establish that distinct VTA circuits generate reward and aversion, and thereby provide a new framework for understanding the circuit basis of adaptive and pathological motivated behaviours.
View details for DOI 10.1038/nature11527
View details for Web of Science ID 000310774300035
View details for PubMedID 23064228
View details for PubMedCentralID PMC3493743