Scott Lowe PhD

Scott Lowe


Research Interests

My current research interests focus around understanding the structure and function of individual cortical columns. In particular, I intend to develop and implement techniques to study the dynamics of cortical oscillations within a cortical column using existing data.

Research into the mammalian neocortex indicates that the structure of the neocortex is reasonably well conserved. Each region of the neocortex is composed of six-layered columnar microcircuits, which are repeated across the surface of the neocortex. It is a plausible speculation that there is a large-scale generic algorithm which is applied throughout the sensory cortices by means of the circuitry in the cortical columns, and if we can understand the interactions between the different layers within the cortical column we might better be able to understand how it functions.

Publications:
2016
  Behavioral-state modulation of inhibition is context-dependent and cell type specific in mouse visual cortex
Pakan, JM, Lowe, SC, Dylda, E, Keemink, S, Currie, SP, Coutts, CA & Rochefort, NL 2016, 'Behavioral-state modulation of inhibition is context-dependent and cell type specific in mouse visual cortex' eLIFE, vol 5. DOI: 10.7554/eLife.14985

Cortical responses to sensory stimuli are modulated by behavioral state. In the primary visual cortex (V1), visual responses of pyramidal neurons increase during locomotion. This response gain was suggested to be mediated through inhibitory neurons, resulting in the disinhibition of pyramidal neurons. Using in vivo two-photon calcium imaging in layers 2/3 and 4 in mouse V1, we reveal that locomotion increases the activity of vasoactive intestinal peptide (VIP), somatostatin (SST) and parvalbumin (PV)-positive interneurons during visual stimulation, challenging the disinhibition model. In darkness, while most VIP and PV neurons remained locomotion responsive, SST and excitatory neurons were largely non-responsive. Context-dependent locomotion responses were found in each cell type, with the highest proportion among SST neurons. These findings establish that modulation of neuronal activity by locomotion is context-dependent and contest the generality of a disinhibitory circuit for gain control of sensory responses by behavioral state.


General Information
Organisations: Edinburgh Neuroscience.
Authors: Pakan, Janelle Mp, Lowe, Scott C, Dylda, Evelyn, Keemink, Sander, Currie, Stephen P, Coutts, Christopher A & Rochefort, Nathalie Li.
Publication Date: 23 Aug 2016
Publication Information
Category: Article
Journal: eLIFE
Volume: 5
ISSN: 2050-084X
Original Language: English
DOIs: 10.7554/eLife.14985
2015
  Shifts of Gamma Phase across Primary Visual Cortical Sites Reflect Dynamic Stimulus-Modulated Information Transfer
Besserve, M, Lowe, SC, Logothetis, NK, Schölkopf, B, Panzeri, S & Kohn, A (ed.) 2015, 'Shifts of Gamma Phase across Primary Visual Cortical Sites Reflect Dynamic Stimulus-Modulated Information Transfer' PLoS Biology, vol 13, no. 9, pp. 1-29. DOI: 10.1371/journal.pbio.1002257
Distributed neural processing likely entails the capability of networks to reconfigure dynamically the directionality and strength of their functional connections. Yet, the neural mechanisms that may allow such dynamic routing of the information flow are not yet fully understood. We investigated the role of gamma band (50–80 Hz) oscillations in transient
modulations of communication among neural populations by using measures of direction-specific causal information transfer. We found that the local phase of gamma-band rhythmic activity exerted a stimulus-modulated and spatially-asymmetric directed effect on the firing rate of spatially separated populations within the primary visual cortex. The relationships between gamma phases at different sites (phase shifts) could be described as a stimulus-modulated
gamma-band wave propagating along the spatial directions with the largest information transfer. We observed transient stimulus-related changes in the spatial configuration of phases (compatible with changes in direction of gamma wave propagation) accompanied by a relative increase of the amount of information flowing along the instantaneous
direction of the gamma wave. These effects were specific to the gamma-band and suggest that the time-varying relationships between gamma phases at different locations mark, and possibly causally mediate, the dynamic reconfiguration of functional connections.
General Information
Organisations: Neuroinformatics DTC.
Authors: Besserve, Michel, Lowe, Scott C., Logothetis, Nikos K., Schölkopf, Bernhard & Panzeri, Stefano.
Pages: 1-29
Publication Date: 22 Sep 2015
Publication Information
Category: Article
Journal: PLoS Biology
Volume: 13
Issue number: 9
ISSN: 1545-7885
Original Language: English
DOIs: 10.1371/journal.pbio.1002257
2012
  Neural correlates of perceptual learning of contrast discrimination in macaque areas V1 and V4
Sanayei, M, Chen, X, Lowe, SC & Thiele, A 2012, 'Neural correlates of perceptual learning of contrast discrimination in macaque areas V1 and V4' 8th Fens Forum of Neuroscience, Barcelona, Spain, 14/07/12 - 18/07/12, .
Perceptual learning (PL) improves sensory abilities through training and these improvements persist for long periods of time.
PL at the psychophysical level has been studied extensively, but changes in neuronal sensitivity and coding that may occur as learning progresses are poorly understood.
To investigate these neuronal changes, we engaged two macaque monkeys in a contrast discrimination task, where he had to judge whether a test stimulus had a higher or lower contrast compared to a sample stimulus. We recorded continuous multi-unit (envelope MUA) activity from chronically implanted electrodes (Utah arrays) in V1 and V4.
General Information
Organisations: Neuroinformatics DTC.
Authors: Sanayei, Mehdi, Chen, Xing, Lowe, Scott C. & Thiele, Alex.
Publication Date: 2012
Publication Information
Category: Poster
Original Language: English

Projects:
Analysis and modelling of experimental data from multi-electrode recordings in the visual cortex (PhD)