Warm-Sensitive Neurons that Control Body Temperature.

Thermoregulation is one of the most vital functions of the brain, but how temperature information is converted into homeostatic responses remains unknown. Here, we use an unbiased approach for activity-dependent RNA sequencing to identify warm-sensitive neurons (WSNs) within the preoptic hypothalamus that orchestrate the homeostatic response to heat. We show that these WSNs are molecularly defined by co-expression of the neuropeptides BDNF and PACAP. Optical recordings in awake, behaving mice reveal that these neurons are selectively activated by environmental warmth. Optogenetic excitation of WSNs triggers rapid hypothermia, mediated by reciprocal changes in heat production and loss, as well as dramatic cold-seeking behavior. Projection-specific manipulations demonstrate that these distinct effectors are controlled by anatomically segregated pathways. These findings reveal a molecularly defined cell type that coordinates the diverse behavioral and autonomic responses to heat. Identification of these warm-sensitive cells provides genetic access to the core neural circuit regulating the body temperature of mammals. PAPERCLIP.

Gingivoperiosteoplasty in Children with Cleft Lip and Palate: The Need for Alveolar Bone Grafting.

OBJECTIVE: This study aimed to determine the efficacy of gingivoperiosteoplasty (GPP) in preventing alveolar bone grafting (ABG) among children with cleft lip and palate (CLP). DESIGN/SETTING: Retrospective university hospital single center study. PATIENTS: Children with CLP treated with GPP from 2000-2015 were included. Those under eight years of age, without definitive conclusions regarding need for ABG or with incomplete data were excluded. INTERVENTIONS: Included patients were analyzed for demographics, cleft type, age at GPP, associated cleft surgery, use of nasoalveolar molding (NAM), indication for ABG, operating surgeon and presence of residual alveolar fistula. T-tests and Fisher's exact tests were utilized for statistical analysis. MAIN OUTCOME MEASURE: The need for ABG. RESULTS: Of the 1682 children identified with CLP, 64 underwent GPP and met inclusion criteria. 78% of patients with CLP who underwent GPP were recommended for ABG. Those who received GPP at a younger age (P = .004) and at the time of initial cleft lip repair (P = .022) were less likely to be recommended for ABG. Patients with complete CLP were more likely to be recommended for ABG than patients with cleft lip and alveolus only (P = .015). The operating surgeon impacted the likelihood of ABG (P = .004). Patient gender, race, ethnicity, laterality, and NAM were not significantly associated with recommendation for ABG. CONCLUSION: GPP does not preclude the need for ABG. Therefore, the success of ABG after GPP and maxillary growth restriction should be analyzed further to determine if GPP is a worthwhile adjunct to ABG in cleft care.

Thirst neurons anticipate the homeostatic consequences of eating and drinking.

Thirst motivates animals to drink in order to maintain fluid balance. Thirst has conventionally been viewed as a homeostatic response to changes in blood volume or tonicity. However, most drinking behaviour is regulated too rapidly to be controlled by blood composition directly, and instead seems to anticipate homeostatic imbalances before they arise. How this is achieved remains unknown. Here we reveal an unexpected role for the subfornical organ (SFO) in the anticipatory regulation of thirst in mice. By monitoring deep-brain calcium dynamics, we show that thirst-promoting SFO neurons respond to inputs from the oral cavity during eating and drinking and then integrate these inputs with information about the composition of the blood. This integration allows SFO neurons to predict how ongoing food and water consumption will alter fluid balance in the future and then to adjust behaviour pre-emptively. Complementary optogenetic manipulations show that this anticipatory modulation is necessary for drinking in several contexts. These findings provide a neural mechanism to explain longstanding behavioural observations, including the prevalence of drinking during meals, the rapid satiation of thirst, and the fact that oral cooling is thirst-quenching.