25th annual computational neuroscience meeting: CNS-2016

The same neuron may play different functional roles in the neural circuits to which it belongs. For example, neurons in the Tritonia pedal ganglia may participate in variable phases of the swim motor rhythms [1]. While such neuronal functional variability is likely to play a major role the delivery of the functionality of neural systems, it is difficult to study it in most nervous systems. We work on the pyloric rhythm network of the crustacean stomatogastric ganglion (STG) [2]. Typically network models of the STG treat neurons of the same functional type as a single model neuron (e.g. PD neurons), assuming the same conductance parameters for these neurons and implying their synchronous firing [3, 4]. However, simultaneous recording of PD neurons shows differences between the timings of spikes of these neurons. This may indicate functional variability of these neurons. Here we modelled separately the two PD neurons of the STG in a multi-neuron model of the pyloric network. Our neuron models comply with known correlations between conductance parameters of ionic currents. Our results reproduce the experimental finding of increasing spike time distance between spikes originating from the two model PD neurons during their synchronised burst phase. The PD neuron with the larger calcium conductance generates its spikes before the other PD neuron. Larger potassium conductance values in the follower neuron imply longer delays between spikes, see Fig. 17.Neuromodulators change the conductance parameters of neurons and maintain the ratios of these parameters [5]. Our results show that such changes may shift the individual contribution of two PD neurons to the PD-phase of the pyloric rhythm altering their functionality within this rhythm. Our work paves the way towards an accessible experimental and computational framework for the analysis of the mechanisms and impact of functional variability of neurons within the neural circuits to which they belong

Exploring attachment incoherence in bereaved families’ therapy narratives: An attachment theory-informed thematic analysis

Attachment theory predicts that family bereavement leads even securely attached individuals to experience temporary attachment insecurity. This paper explores how incoherence, a narrative marker of attachment insecurity, is displayed in the talk of families undergoing bereavement family therapy. This study uses the lens of attachment theory, and specifically the Adult Attachment Interview (AAI), to explore how members of five families talked about the loss of a close family member and how interactions between therapist and family members could hinder a coherent dialogue about the death. The families were recruited through Winston’s Wish, a UK-based family bereavement charity. The analysis centres on the “Telling the story” intervention, used at the start of therapy, in which family members together tell the story of the death. Families also re-told the story in an extra family session towards the end of the therapy for the purposes of this research. Transcripts of the therapy sessions were analysed using thematic analysis, with some codes developed directly from the unresolved loss codes of the AAI and other codes generated from analysing the transcripts through the lens of attachment theory. Through a micro focus on therapy process, the study provides tentative support for suppositions in attachment theory about the psychological importance of (fostering) coherent speech as well as information about potentially helpful versus unhelpful therapist actions in family bereavement therapy. The findings have relevance for bereavement therapy interventions, therapy training and research practice