Donald Doherty's blog

Author: Donald Doherty

  • Whole Brain Catalog app for iPad, iPhone, and iPod touch

    Earlier blog posts looked at the Whole Brain Catalog application, which provides a portal to a broad range of neuroscience data (see Other related blog posts below). Two days ago the Whole Brain Catalog team from the University of California San Diego released a version of the Whole Brain Catalog application for the iPad, iPhone, and iPod touch.

    Figure 1. A close up view of a triple labeled cerebellum section on an iPhone using the Whole Brain Catalog app for iPad, iPhone and iPod touch.

    Note: If you run into any issues running the Whole Brain Catalog app, check to make sure your device is connected with the Internet.

    The introductory video is attractive and may be informative for those less familiar with neuroscience. On the iPhone and iPod touch the application opens to thirteen images that act as icons arrayed across the horizontal view. Each of these represents some aspect of the nervous system that you may examine in more detail by double tapping the icon.

    Note: The application is strictly horizontal on iPad, iPhone, and iPod touch.

    The icons represent the following:

    • Rat cerebellar cortex (triple labeled)
    • Another section from rat cerebellar cortex (triple labeled)
    • 3View mouse neuropil
    • Fruitfly DL1 cell
    • Mouse reference atlas (sagittal)
    • Mouse reference atlas (coronal)
    • Mouse RORB ISH marker
    • Developing mouse
    • Cat brainstage (sagital)
    • Embryonic 17a rat
    • Primate nissle stained brain section
    • Human brain section
    • Mouse brain section

    Each section may be viewed in beautiful detail except, for some reason, the human brain section. Some are stunning (see for example Figure 1). However, currently the Whole Brain Catalog app for iPad, iPhone, and iPod touch is a sampler to entice the appetite. It’s not yet a tool for reference or serious research.

    Note: The Whole Brain Catalog app for iPad, iPhone, and iPod touch is free and may be downloaded from the iTunes app store by clicking here.

    Other related blog posts:

    Whole Brain Catalog: the Google Earth for the Brain

    Whole Brain Catalog: Brain Cells and Molecules

    Whole Brain Catalog: Visualizing Neural Network Activity

  • Spiral Waves in the Brain

    Imaging brain activity using voltage sensitive dyes has revealed propagating waves of neuronal activity in the brain. It’s been hypothesized that propagating waves of activity may contribute to cerebral cortical signal processing by determining when and where the cortex is depolarized in relation to a sensory or motor event.

    Spiral waves are a particular kind of propagating wave that rotate around a center point. Spiral waves have been observed in turtle visual cortex and in brain slices but it wasn’t known if they may be found in the intact mammalian brain. Today’s paper “Spiral Wave Dynamics in Neocortex” (published December 9, 2010 in Neuron) reports on an investigation into the existence of spiral waves in intact rat brains.

    The research team placed rats into two states and then looked for spiral waves emerging from the cerebral cortex. One state was induced by applying carbachol and bicuculline to the brain. Local excitatory connections in the cerebral cortex were greatly enhanced in this condition and oscillations at around 10 Hertz were induced. The other state was achieved with low levels of pentobarbital anesthesia. In this state, the cortex alternated between theta (around 6 Hz) and delta (1-4 Hz) rhythms that resembled the rapid eye movement (REM) state in rodent natural sleep.

    Spiral waves were observed under both conditions. Furthermore, the emergence of spiral waves appeared to have a large impact on the oscillation frequency, spatial coherence, and amplitude of cortical activity.

  • Imagine Eating 30 M&M Candies and Eat Less

    Eating a food item, pasta for instance, typically leads to the person eating less of that food less for a while. This well studied phenomenon is known as habituation. However, intuitively we believe that imagining a food item increases its desirability and our subsequent consumption. Research has been showing that perception and mental imagery engage similar brain systems and have similar outcomes. This would suggest that imagining a food item would result in habituating to that food item. A team from Carnegie Mellon University set out to experimentally test what would happen.

    Reported in the paper “Thought for Food: Imagined Consumption Reduces Actual Consumption” published December 10, 2010 in Science.

    The research team carried out a set of five experiments using M&M candies to see if repeated mental simulation of eating the M&Ms alone can result in habituation. Indeed, the results repeatedly showed that when individuals imagined eating 30 M&M candies they ate significantly fewer actual M&Ms than those who imagined eating just 3 candies. Their seems to be little difference between imagined food and real food to to the brain systems involved in habituation.