Courtship is an innate sexually dimorphic behaviour that can be observed in naive animals without previous learning or experience, suggesting that the neural circuits that mediate this behaviour are developmentally programmed. In Drosophila, courtship involves a complex yet stereotyped array of dimorphic behaviours that are regulated by Fru(M), a male-specific isoform of the fruitless gene. Fru(M) is expressed in about 2,000 neurons in the fly brain, including three subpopulations of olfactory sensory neurons and projection neurons (PNs). One set of Fru(+) olfactory neurons expresses the odorant receptor Or67d and responds to the male-specific pheromone cis-vaccenyl acetate (cVA). These neurons converge on the DA1 glomerulus in the antennal lobe. In males, activation of Or67d(+) neurons by cVA inhibits courtship of other males, whereas in females their activation promotes receptivity to other males. These observations pose the question of how a single pheromone acting through the same set of sensory neurons can elicit different behaviours in male and female flies. Anatomical or functional dimorphisms in this neural circuit might be responsible for the dimorphic behaviour. We therefore developed a neural tracing procedure that employs two-photon laser scanning microscopy to activate the photoactivatable green fluorescent protein. Here we show, using this technique, that the projections from the DA1 glomerulus to the protocerebrum are sexually dimorphic. We observe a male-specific axonal arbor in the lateral horn whose elaboration requires the expression of the transcription factor Fru(M) in DA1 projection neurons and other Fru(+) cells. The observation that cVA activates a sexually dimorphic circuit in the protocerebrum suggests a mechanism by which a single pheromone can elicit different behaviours in males and in females.

In the antennal lobe of Drosophila, information about odors is transferred from olfactory receptor neurons (ORNs) to projection neurons (PNs), which then send axons to neurons in the lateral horn of the protocerebrum (LHNs) and to Kenyon cells (KCs) in the mushroom body. The transformation from ORN to PN responses can be described by a normalization model similar to what has been used in modeling visually responsive neurons. We study the implications of this transformation for the generation of LHN and KC responses under the hypothesis that LHN responses are highly selective and therefore suitable for driving innate behaviors, whereas KCs provide a more general sparse representation of odors suitable for forming learned behavioral associations. Our results indicate that the transformation from ORN to PN firing rates in the antennal lobe equalizes the magnitudes of and decorrelates responses to different odors through feedforward nonlinearities and lateral suppression within the circuitry of the antennal lobe, and we study how these two components affect LHN and KC responses.antennal lobe | decorrelation | lateral horn | normalization | olfaction I n the olfactory system, as in other sensory systems, signals from primary receptors are processed and transformed before being relayed to higher brain areas. In Drosophila melanogaster, olfactory receptor neurons (ORNs) located in the antennae and maxillary palps synapse onto projection neurons (PNs) within the glomeruli of the antennal lobes (Fig. S1). ORNs expressing a given receptor converge on an anatomically invariant glomerulus. PNs innervate a single glomerulus and thus receive their primary input from ORNs expressing the same olfactory receptor (1), although crossglomerular interactions mediated by interneurons are also present (2-5). The PNs send their axons to two distinct regions of the fly brain, the lateral horn and the mushroom body. By constructing models of neurons in these regions, we study the effects of the transformations arising from circuitry within the antennal lobe on the capacity of neurons in the lateral horn and the mushroom body to represent and discriminate odors.Any functional interpretation of the transformation from ORN to PN responses depends on the nature of the processing being performed by the third-order neurons that receive PN input. The lateral horn and mushroom body appear to be involved in different forms of sensory processing. The lateral horn is believed to be important in generating innate behaviors (6), including those elicited by pheromones (7). PN projections to lateral horn neurons (LHNs) are spatially stereotyped (8, 9) and clustered (10), suggesting that circuits in this region may be "hardwired" for the detection of specific odors that elicit innate behavioral responses. The mushroom body is implicated in decision making (11) and in the formation of associative memories (12, 13). Both calcium imaging (14) and electrophysiology (15) indicate that the responses of Kenyon cell (KCs) in the mushroom body are sparse, with e...

BackgroundTobacco smoking is the leading cause of preventable death in the United States, and the annual economic burden attributable to smoking exceeds US $300 billion. Obstacles to smoking cessation include limited access and adherence to effective cessation interventions. Technology can help overcome these obstacles; many smartphone apps have been developed to aid smoking cessation, but few that conform to the US clinical practice guideline (USCPG) have been rigorously tested and reported in the literature. Clickotine is a novel smartphone app for smoking cessation, designed to deliver the essential features of the USCPG and engineered to engage smokers by personalizing intervention components.ObjectiveOur objective was to assess the engagement, efficacy, and safety of Clickotine in an initial, single-arm study. Outcomes measured were indicators of engagement with the smartphone app (number of app opens, number of interactions with the Clickotine program, and weeks active with Clickotine), cessation outcomes of 7- and 30-day self-reported abstinence from smoking, and negative health events.MethodsWe recruited US residents between 18 and 65 years of age who owned an iPhone and smoked 5 or more cigarettes daily for the study via online advertising. Respondents were prescreened for eligibility by telephone and, if appropriate, directed to a Web portal to provide informed consent, confirm eligibility, and download the Clickotine app. Participants completed study assessments via the online portal at baseline and after 8 weeks. Data were collected in Amazon S3 with no manual data entry, and access to all data was maximally restrictive, logged, and auditable.ResultsA total of 416 participants downloaded the app and constituted the intention-to-treat (ITT) sample. On average, participants opened the Clickotine app 100.6 times during the 8-week study (median 69), logged 214.4 interactions with the Clickotine program (median 178), and remained engaged with Clickotine for 5.3 weeks (median 5). Among the ITT sample, 45.2% (188/416) reported 7-day abstinence and 26.2% (109/416) reported 30-day abstinence from smoking after 8 weeks. Completer analysis focused on 365 (87.7%) of the 416 enrolled participants who completed the 8-week questionnaire revealed that 51.5% (188/365) of completers reported 7-day abstinence and 29.9% (109/365) reported 30-day abstinence. Few adverse events, mostly consistent with nicotine withdrawal symptoms, were reported and overall no safety signal was detected.ConclusionsIn this initial single-arm trial, Clickotine users appeared to demonstrate encouraging indicators of engagement in terms of the number of app opens, number of program interactions, and continued engagement over time. Clickotine users reported encouraging quit rates while reporting few adverse events. Future research is warranted to assess Clickotine’s efficacy in a randomized controlled trial.Trial RegistrationClinicaltrials.gov NCT02656745; https://clinicaltrials.gov/ct2/show/NCT02656745 (Archived by WebCite at http://www.webcita...

Background and Objectives: Highly potent synthetic opioids (HPSO) are increasingly responsible for opioid overdose deaths in the United States. Methods: In an open-label, uncontrolled trial to test the feasibility of extended-release buprenorphine (BXR) injection treatment of heroin-using individuals with opioid use disorder testing positive for HPSO, participants were enrolled and began an induction with sublingual BXR (n = 5). During the induction, ancillary medications (clonidine, clonazepam, zolpidem, and prochlorperazine) were provided for breakthrough opioid withdrawal symptoms. Results: Two participants received the BXR injection on the second day of the induction and three participants on the third day. Discussion and Conclusion: All five participants were retained at least 1-month postinduction. Scientific Significance: It may be feasible to provide BXR treatment to HPSO-positive heroin users rapidly to achieve clinical stabilization.