Registration now open for Careers in Neuroscience Symposium Galway 2014

Originally posted on Neuroscience Ireland:

The organising committee for Careers in Neuroscience Symposium Galway 2014 (CNS Galway 2014), would like to invite to you attend our symposium, which will be held on Wednesday 26th November 2014 in NUI Galway.

CNS Galway 2014 is a symposium focused on career opportunities in neuroscience which is organised by early-career researchers from the Galway Neuroscience Centre in conjunction with Neuroscience Ireland. This event complements the Young Neuroscientists Symposium at Trinity College on 20th Sept.

We welcome a range of high-calibre and distinguished experts (including Prof. John Cryan, Dr. Will Spooren, Prof. William O’Connor) to share their experience and career highlights with attendees.

Discuss and debate potential career pathways in academia, industry, science communication, entrepreneurship and alternative careers with professionals in the field.

Through open discussions and social events, there will be plenty of networking opportunities to meet these experts in an informal and friendly environment…

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Manipulated By Metaphors

Originally posted on The Dish:

by Dish Staff

Figurative language may warp your perception of reality. Britt Peterson explains:

Lera Boroditsky, an associate professor of cognitive science at the University of California at San Diego, has written a series of papers on the effect of figurative language, particularly metaphors of space and time, on reasoning. One paper, written with Paul Thibodeau, an assistant professor of psychology at Oberlin College, showed that substituting just one word in a text about a crime wave ravaging an imaginary town – comparing crime to a “beast” instead of a “virus” – completely changed how readers responded to the problem. People who read that crime was a beast were far more likely to advocate putting more police on the streets or locking up criminals; people who read “virus” were far more likely to push for education and social reforms. And yet, when people cited the factors behind their decisions, no one mentioned…

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Chronic immobilization stress occludes in vivo cortical activation in an animal model of panic induced by carbon dioxide inhalation

Dont Panic

Dont Panic (Photo credit: Wikipedia)

It has been known since at least the 1920’s that inhaling high amounts of CO2 (20%) induces panic attacks in healthy individuals. There is a remarkable literature deriving from diving and respiratory physiology in submariners available treating this topic. The great father and son team [John Scott Haldane (the physiologist and polymath) and J. B. S. Haldane (the physiologist, geneticist, evolutionary biologist, biomathematician and wit)] contributed many papers examining the effects of such CO2 inhalation (e.g., e.g.).  Those involved in the drafting of  Torture Memos cite waterboarding as causing elevations in blood carbon dioxide levels (hypercapnia; see this and this for a further discussion). Panic disorder patients show panic response to even small doses of CO2 inhalation. Patients with anxiety disorders or a family history of anxiety disorder are also more susceptible to show panic response to CO2 inhalation. Inhaling hypercapnic gases, such as various concentrations of CO2, has been hypothesized to trigger a biological alarm system that has evolved to serve as a suffocation monitor. Earlier studies have tried to infer the neural circuit involved in this panic response. The hippocampus, amygdala and cortex  have all been hypothesized to play a vital role in CO2-induced panic response. Here, we examine the interaction between the induction of prior chronic stress and the panic response induced by breath differing concentrations of CO2. [Download the paper]

Chronic immobilization stress occludes in vivo cortical activation in an animal model of panic induced by carbon dioxide inhalation*

Mohammed Mostafizur Rahman, Christian M. Kerskens, Sumantra Chattarji and Shane M. O‘Mara

Abstract

Breathing high concentrations of carbon dioxide (CO2) can trigger panic and anxiety in humans. CO2 inhalation has been hypothesized to activate neural systems similar to those underlying fear learning, especially those involving the amygdala. Amygdala activity is also upregulated by stress. Recently, however, a separate pathway has been proposed for interoceptive panic and anxiety signals, as patients exhibited CO2-inhalation induced panic responses despite bilateral lesions of the amygdala. This paradoxical observation has raised the possibility that cortical circuits may underlie these responses. We sought to examine these divergent models by comparing in vivo brain activation in unstressed and chronically-stressed rats breathing CO2. Regional cerebral blood flow measurements using functional Magnetic Resonance Imaging (fMRI) in lightly-anaesthetized rats showed especially strong activation of the somatosensory cortex by CO2 inhalation in the unstressed group. Strikingly, prior exposure to chronic stress occluded this effect on cortical activity. This lends support to recent clinical observations and highlights the importance of looking beyond the traditional focus on limbic structures, such as the hippocampus and amygdala, to investigate a role for cortical areas in panic and anxiety in humans.

*I am delighted to have conducted this work in collaboration with my colleagues at the National Centre for Biological Sciences (NCBS), Bangalore (Shona Chatterji and his PhD student Mohammed Mostafizur Rahmen). Our collaboration was supported by a Science Foundation Ireland – Short-Term Travel Fellowship.

 

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This is what happens in your brain when you hear your favorite song, whether it’s Bieber, Biggie or The Beatles

Originally posted on Quartz:

In 1973, the British rock star Peter Frampton posed an important scientific question via a killer talkbox solo: “Do you feel like I do?”

According to a new study, when it comes to our reactions to our favorite music, the answer is, “Yes.”

The study, published August 28 in Nature, shows that people brains exhibit the same patterns of connections when they listen to their personal favorite songs, whether those songs are free jazz, Swedish progressive death metal, or anything in between.

Researchers monitored each participant’s brain activity while they listened to a series of songs: a genre-spanning control playlist picked by the researchers, and one song the participant had identified in advance as their favorite. (They had diverse and eclectic taste, including (pdf) songs from the Mormon Tabernacle Choir, the Goo Goo Dolls and the Notorious B.I.G., among others.) Afterwards, the participants rated how much they liked each of the control…

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Please RT: Immediate Postdoctoral Fellowship Vacancy in Behavioural Neurophysiology at Trinity College Dublin

Wellcome Trust-Funded Project focused on freely-moving recordings in

English: Front Square at Trinity College, Dubl...

English: Front Square at Trinity College, Dublin, Ireland with Campanile and Graduate Memorial Building (Photo credit: Wikipedia)

vivo.

Exciting, scientifically compelling and mature project, with plenty of room for development.

Experience of electrophysiology/neurophysiology is essential; experience in freely-moving recordings is desirable. The ideal candidate will possess high levels of intellectual curiosity, drive and motivation.

Fully equipped lab with ample technical and analytic back-up. The successful applicant will conduct large-scale recordings of deep-brain midline structures. This project is part of a long-standing collaboration with colleagues at Cardiff University: this position is funded as part of a Wellcome Trust Senior Investigator Award.

Some recent relevant papers (and here for a full listing): 

  • Rahman, MM, Kerskens, CM, Chattarji, S, O‘Mara, SM (2014). Chronic immobilization stress occludes in vivo cortical activation in an animal model of panic induced by carbon dioxide inhalation. Frontiers in Behavioral Neuroscience, in press
  • Tsanov M, Chah E, Noor MS, Egan C, Reilly RB, Aggleton JP, Erichsen JT, Vann SD, O’Mara SM. The irregular firing properties of thalamic head direction cells mediate turn-specific modulation of the directional tuning curve. J Neurophysiol. 2014 Aug 13. pii: jn.00583.2013. [Epub ahead of print]
  • Jankowski MM, Islam MN, Wright NF, Vann SD, Erichsen JT, Aggleton JP, O’Mara SM. (2014). Nucleus reuniens of the thalamus contains head direction cells. eLife, e03075. doi: 10.7554/eLife.03075. [Epub ahead of print]
  • Passecker J, Barlow S, O’Mara SM. (2014). Dissociating effects of acute photic stress on spatial, episodic-like and working memory in the rat. Behav Brain Res. 272:218-25.
  • Tsanov M, Chah E, Reilly R, O’Mara SM. (2013) Respiratory cycle entrainment of septal neurons mediates the fast coupling of sniffing rate and hippocampal theta rhythm. Eur J Neurosci. Dec 11. doi: 10.1111/ejn.12449.
  • Jankowski, MM, Ronnqvist, KC, Tsanov, M, Vann, SD, Wright, NF, Erichsen, JT, Aggleton, JP & O’Mara SM (2013). The Anterior Thalamus Provides A Subcortical Circuit Supporting Memory And Spatial Navigation. Frontiers in Systems Neuroscience, doi: 10.3389/fnsys.2013.00045.
  • Wright, N, Vann, SD, Erichsen, J, O’Mara, SM & Aggleton, JP (2013). Segregation of parallel inputs to the anteromedial and anteroventral thalamic nuclei of the rat. Journal of Comparative Neurology, Mar 16. doi: 10.1002/cne.23325. [Epub ahead of print]
  • Hok et al. (2012). Hippocampal Dynamics Predict Inter-Individual Cognitive Differences in Rats. J Neurosci, in press
  • Chah et al. (2011). A waveform independent cell identification method to study long-term variability of spike recordings. Conf Proc IEEE Eng Med Biol Soc. 2011:2558-61.
  • Tsanov et al. (2011). Theta-modulated head direction cells in the rat anterior thalamus. J Neurosci, 31, 9489-9502.
  • Wang et al. (2011). Rosiglitazone enhances learning, place cell activity, and synaptic plasticity in middle-aged rats. Neurobiol Aging. Oct 3. [Epub ahead of print]
  • Passecker et al. (2011). Dissociation of dorsal hippocampal regional activation under the influence of stress in freely-behaving rats. Frontiers Behav Neurosci, 5, 66, 1-7 doi: 10.3389/fnbeh.2011.00066
  • Tsanov et al. (2011). Oscillatory Entrainment of Thalamic Neurons by Theta Rhythm in Freely-Moving Rats. J Neurophys, 105, 4-17.
  • Chah et al. (2011). Automated spike sorting algorithm based on Laplacian eigenmaps and k-means clustering J Neural Engineering, 8(1):016006

Enquiries and applications by email (CV, three academic references, list of publications, cover letter) to Prof Shane O’Mara (smomara@tcd.ie).

Further details on Trinity College Institute of Neuroscience (TCIN): http://www.tcd.ie/Neuroscience/

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Remind me again why aerobic exercise is good for my brain (and mood, and thinking)…

English: US 1988–2007 No Leisure-Time Physical...

English: US 1988–2007 No Leisure-Time Physical Activity Trend Chart (Photo credit: Wikipedia)

There are lots of reasons why regular aerobic exercise is good for the brain – the effects of exercise on brain volume, cognition and mood are profound and enduring. Here are a few key papers.

In an early review paper, Colcombe and Kramer (2003) conducted a meta-analysis of 18 interventional studies, conducted over a 25-year period. Their general conclusion was that fitness training in the elderly increased performance by approximately .5 of a standard deviation across all tasks tested. Maximal effects were found for tasks related to executive functions, (i.e., aspects of higher cognition principally associated with the functions of prefrontal cortex). The next greatest set of effects were found for cognitive functions associated with the transition from effortful learning to automatic processing (i.e. tasks such as driving, that demand concentration and attention during their learning and execution, but which through practice become more automatic). The next greatest effect was on visuo-spatial factors (i.e., factors associated with visualising and interacting with the three-dimensional world). Finally, effects were found on low-level reaction time tasks: generalised increases in the speed of response to stimuli. The authors concluded that neurocognitive benefits of exercise are apparent right across the life span, but the greatest measurable effects of fitness training are more evident in older participants.

Underscoring these conclusions, Eriksen et al (2011) found that in a randomised control trial in 120 older people, that an exercise intervention reversed declines in hippocampal volumes (by c. 1-2 years – i.e. about 2%) using structural MRI, concomitant with improvements in memory function and increases in circulating BDNF. In other words, regular exercise increases the volume of key brain areas concerned with memory.

Experimentally, aerobic fitness has generally been focused upon in a gymnasium setting (usually using treadmills). Thus, activity can be monitored and quantified. Aerobic status is assessed directly through validated measures of cardiorespiratory function, and changes in cardiovascular status can be monitored directly. Additionally, participants can be prescribed a fitness programme extending for verifiable periods of time (say three one-hour sessions per week). This advantage of controlled laboratory trials is also a disadvantage. Participants volunteering for such trials are, by definition, highly-motivated and interested in engaging with the training regime and sustaining it over a sufficiently great period of time that effects on neurocognitive function may become apparent. Field studies of these functions are much less common and generally rely on self-report measures obtained through the use of questionnaires (see, e.g., Giacobbi et al, 2005).

Laboratory-based interventions have another confound. Recent studies have shown that mere exposure, on an intermittent basis, to nature, has a strong, sustained effect on mood. In a clever recent study, Nisbet and Zelenski (2011) examined the effect of people undertaking walks where they are exposed to nature, versus walking in an enclosed environment. Carlton University, Ontario, is subject to extremes of weather. A substantial fraction of the large campus is connected via a system of extended underground tunnels. They investigated (150 participants; 18-48 years) the effect of walking between two locations on the campus: either through an underground tunnel, or overground past an urban space with trees and other features of the natural environment. Participants underestimated dramatically the likely hedonic benefit of undertaking a seventeen-minute walk outdoors versus a walk indoors. They also found that the effect of the walk itself on affect, or mood, was very substantial (an improvement in score of one third), relative to individuals who undertook a walk indoors. Thus, activity in an outdoor setting is an important and positive moderating variable on individual mood, independent of its effects on cognition.

In a final noteworthy paper, Killingsworth and Gilbert (2011), using a smartphone app, analysed repeated point measures of mood (‘experience sampling’) in 2250 people (ages: 18-88 years). ‘Exercising’ was found to be among the top-three highest mood-enhancing activities in this sample.

Conclusion: get out and walk – regularly!

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The irregular firing properties of thalamic head direction cells mediate turn-specific modulation of the directional tuning curve

Take-home message: Anterior thalamic head direction cells are interesting in all sorts of ways. Here, we show that head direction cells remain active during sleep (how interesting is that?!), replicate the finding that these cells fire at different rates depending on whether the head makes clockwise or counterclockwise movements, and that the origin of this difference might lie in the intrinsic firing properties of these neurons. [Download the paper]

The irregular firing properties of thalamic head direction cells mediate turn-specific modulation of the directional tuning curve

Marian Tsanov , Ehsan Chah , Muhammad S. Noor , Catriona Egan , Richard B. Reilly , John P. Aggleton , Jonathan T. Erichsen , Seralynne D. Vann , Shane M. O’Mara
Journal of Neurophysiology

Published 13 August 2014

Equivalent circuit for the cell membrane in th...

Equivalent circuit for the cell membrane in the Hodgkin-Huxley model (Photo credit: Wikipedia)

Vol. no. DOI: 10.1152/jn.00583.2013

ABSTRACT

Head-direction cells encode an animal’s heading in the horizontal plane. However, it is not clear why the directionality of a cell’s mean firing rate differs for clockwise, compared to counter-clockwise head turns (this difference is known as the ‘separation angle’) in anterior thalamus. Here we investigated, in freely-behaving rats, if intrinsic neuronal firing properties are linked to this phenomenon. We found a positive correlation between the separation angle and the spiking variability of thalamic head-direction cells. To test whether this link is driven by hyperpolarisation-inducing currents, we investigated the effect of thalamic reticular inhibition during high-voltage spindles on directional spiking. While the selective directional firing of thalamic neurons was preserved, we found no evidence for entrainment of thalamic head-direction cells by high-voltage spindle oscillations. We then examined the role of depolarisation-inducing currents in the formation of separation angle. Using a single-compartment Hodgkin-Huxley model, we show that modelled neurons fire with higher frequencies during the ascending phase of sinusoidal current injection (mimicking the head-direction tuning curve), when simulated with higher high-threshold calcium channel conductance. These findings demonstrate that the turn-specific encoding of directional signal strongly depends on the ability of thalamic neurons to fire irregularly in response to sinusoidal excitatory activation. Another crucial factor for inducing phase lead to sinusoidal current injection was the presence of spike-frequency adaptation current in the modelled neurons. Our data support a model in which intrinsic biophysical properties of thalamic neurons mediate the physiological encoding of directional information.

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