Computational modeling of spike generation in serotonergic neurons of the dorsal raphe nucleu

We consider here a single-compartment model of these neurons which is capable of describing many of the known features of spike generation, particularly the slow rhythmic pacemaking activity often observed in these cells in a variety of species. Included in the model are ten kinds of voltage dependent ion channels as well as calcium-dependent potassium current. Calcium dynamics includes buffering and pumping. In sections 3-9, each component is considered in detail and parameters estimated from voltage clamp data where possible. In the next two sections simplified versions of some components are employed to explore the effects of various parameters on spiking, using a systematic approach, ending up with the following eleven components: a fast sodium current $I_{Na}$, a delayed rectifier potassium current $I_{KDR}$, a transient potassium current $I_A$, a low-threshold calcium current $I_T$, two high threshold calcium currents $I_L$ and $I_N$, small and large conductance potassium currents $I_{SK}$ and $I_{BK}$, a hyperpolarization-activated cation current $I_H$, a leak current $I_{Leak}$ and intracellular calcium ion concentration $Ca_i$. Attention is focused on the properties usually associated with these neurons, particularly long duration of action potential, pacemaker-like spiking and the ramp-like return to threshold after a spike. In some cases the membrane potential trajectories display doublets or have kinks or notches as have been reported in some experimental studies. The computed time courses of $I_A$ and $I_T$ during the interspike interval support the generally held view of a competition between them in influencing the frequency of spiking. Spontaneous spiking could be obtained with small changes in a few parameters from their values with driven spiking.Comment: The abstract has been truncate

Feeling Happy and Healthy, Having Fun and Friends: Children's understanding of well-being: a qualitative study

Introduction: The importance of promoting health and well-being has been recognised in recent Government reports and interventions. However, health and mental health have largely been conceptualised as an absence of illness and distress, rather than a presence of positive health or wellness. There has been relatively little attention to this important area, and less work on children's understanding of well-being. Method: This study uses a small-scale qualitative approach to consider how children understand well-being. Twenty school children took part in semi-structured interviews to elicit their definitions of well-being and the thoughts, feelings and beliefs associated with life going well. The interviews were analysed using Interpretative Phenomenological Analysis. Results: Four main themes were developed from the interview data: 'self', 'self in relation to others', 'growing up' and 'the role of adults'. These were presented, illustrated with verbatim quotation from the interviews. The four themes could also be brought together under an overarching theme of self-definition. A wide range of definitions and thoughts, feelings and beliefs were generated by children in the interviews. Discussion: Children's definitions of well-being in this study reflected a more holistic definition, incorporating elements of social, emotional and physical well-being. Well-being was not understood solely in terms of an 'absence of illness'. There was some overlap with other recent conceptualisations of well-being. This is discussed in relation to the promotion of children's mental health and well-being in different settings, the development of treatment goals, and the role of the positive within psychology and other services

Holograms In Our World

In AdS/CFT, the entanglement wedge EW$(B)$ is the portion of the bulk geometry that can be reconstructed from a boundary region $B$; in other words, EW$(B)$ is the hologram of $B$. We extend this notion to arbitrary spacetimes. Given any gravitating region $a$, we define a max- and a min-entanglement wedge, $e_{\rm max}(a)$ and $e_{\rm min}(a)$, such that $e_{\rm min}(a)\supset e_{\rm max}(a)\supset a$. Unlike their analogues in AdS/CFT, these two spacetime regions can differ already at the classical level, when the generalized entropy is approximated by the area. All information outside $a$ in $e_{\rm max}(a)$ can flow inwards towards $a$, through quantum channels whose capacity is controlled by the areas of intermediate homology surfaces. In contrast, all information outside $e_{\rm min}(a)$ can flow outwards. The generalized entropies of appropriate entanglement wedges obey strong subadditivity, suggesting that they represent the von Neumann entropies of ordinary quantum systems. The entanglement wedges of suitably independent regions satisfy a no-cloning relation. This suggests that it may be possible for an observer in $a$ to summon information from spacelike related points in $e_{\rm max}(a)$, using resources that transcend the semiclassical description of $a$.Comment: 26 pages, 5 figure