Involvement of A13 dopaminergic neurons in prehensile movements but not reward in the rat.

Tyrosine hydroxylase (TH)-containing neurons of the dopamine (DA) cell group A13 are well positioned to impact known DA-related functions as their descending projections innervate target regions that regulate vigilance, sensory integration, and motor execution. Despite this connectivity, little is known regarding the functionality of A13-DA circuits. Using TH-specific loss-of-function methodology and techniques to monitor population activity in transgenic rats in vivo, we investigated the contribution of A13-DA neurons in reward and movement-related actions. Our work demonstrates a role for A13-DA neurons in grasping and handling of objects but not reward. A13-DA neurons responded strongly when animals grab and manipulate food items, whereas their inactivation or degeneration prevented animals from successfully doing so-a deficit partially attributed to a reduction in grip strength. By contrast, there was no relation between A13-DA activity and food-seeking behavior when animals were tested on a reward-based task that did not include a reaching/grasping response. Motivation for food was unaffected, as goal-directed behavior for food items was in general intact following A13 neuronal inactivation/degeneration. An anatomical investigation confirmed that A13-DA neurons project to the superior colliculus (SC) and also demonstrated a novel A13-DA projection to the reticular formation (RF). These results establish a functional role for A13-DA neurons in prehensile actions that are uncoupled from the motivational factors that contribute to the initiation of forelimb movements and help position A13-DA circuits into the functional framework regarding centrally located DA populations and their ability to coordinate movement

Increased levels and pulsatility of Follicle-Stimulating Hormone in mothers of hereditary dizygotic twins

According to the endocrine model of hereditary dizygotic twinning, high FSH is responsible for multiple ovulation and pregnancy. Our study explored the underlying neuroendocrine causes

Stability Analysis of Frame Slotted Aloha Protocol

Frame Slotted Aloha (FSA) protocol has been widely applied in Radio Frequency Identification (RFID) systems as the de facto standard in tag identification. However, very limited work has been done on the stability of FSA despite its fundamental importance both on the theoretical characterisation of FSA performance and its effective operation in practical systems. In order to bridge this gap, we devote this paper to investigating the stability properties of FSA by focusing on two physical layer models of practical importance, the models with single packet reception and multipacket reception capabilities. Technically, we model the FSA system backlog as a Markov chain with its states being backlog size at the beginning of each frame. The objective is to analyze the ergodicity of the Markov chain and demonstrate its properties in different regions, particularly the instability region. By employing drift analysis, we obtain the closed-form conditions for the stability of FSA and show that the stability region is maximised when the frame length equals the backlog size in the single packet reception model and when the ratio of the backlog size to frame length equals in order of magnitude the maximum multipacket reception capacity in the multipacket reception model. Furthermore, to characterise system behavior in the instability region, we mathematically demonstrate the existence of transience of the backlog Markov chain.Comment: 14 pages, submitted to IEEE Transaction on Information Theor

Early intervention for obsessive compulsive disorder : An expert consensus statement

© 2019 Elsevier B.V.and ECNP. All rights reserved.Obsessive-compulsive disorder (OCD) is common, emerges early in life and tends to run a chronic, impairing course. Despite the availability of effective treatments, the duration of untreated illness (DUI) is high (up to around 10 years in adults) and is associated with considerable suffering for the individual and their families. This consensus statement represents the views of an international group of expert clinicians, including child and adult psychiatrists, psychologists and neuroscientists, working both in high and low and middle income countries, as well as those with the experience of living with OCD. The statement draws together evidence from epidemiological, clinical, health economic and brain imaging studies documenting the negative impact associated with treatment delay on clinical outcomes, and supporting the importance of early clinical intervention. It draws parallels between OCD and other disorders for which early intervention is recognized as beneficial, such as psychotic disorders and impulsive-compulsive disorders associated with problematic usage of the Internet, for which early intervention may prevent the development of later addictive disorders. It also generates new heuristics for exploring the brain-based mechanisms moderating the ‘toxic’ effect of an extended DUI in OCD. The statement concludes that there is a global unmet need for early intervention services for OC related disorders to reduce the unnecessary suffering and costly disability associated with under-treatment. New clinical staging models for OCD that may be used to facilitate primary, secondary and tertiary prevention within this context are proposed.Peer reviewe

Circuit-based interrogation of sleep control.

Sleep is a fundamental biological process observed widely in the animal kingdom, but the neural circuits generating sleep remain poorly understood. Understanding the brain mechanisms controlling sleep requires the identification of key neurons in the control circuits and mapping of their synaptic connections. Technical innovations over the past decade have greatly facilitated dissection of the sleep circuits. This has set the stage for understanding how a variety of environmental and physiological factors influence sleep. The ability to initiate and terminate sleep on command will also help us to elucidate its functions within and beyond the brain