What’s in My Bag?

I was recently asked what I use on a day to day basis when out shooting so I put this post together. I tend to use the same stuff for my personal work as I do when I’m shooting for clients. 

I try to stay as light as possible because, #1 I can’t stand carrying things, and #2 I can’t yet afford to hire an assistant to do it for me (Slightly joking). So this is what I usually take as staples with me, occasionally more lenses but only when necessary:

- Canon 5D Mark II

- Sigma 24-70mm f/2.8

- Manfrotto Aluminium Tripod

- Retina Macbook Pro 13.3”

- iPhone

- 1TB Hard Drive

- Several batteries, CF Cards and Microfibres

All this together comes to about 4kg which is quite a bit of heft when I’m off places. Although to be honest I very rarely use the tripod for my work.

Freddie Ardley Photography

Check out Freddie’s: Instagram Facebook Website 

Modeling cell connections in the retina

With 576-megapixel resolution, our eyes are incredible cameras, capturing 72-times more high-definition detail than the iPhone 6. To do this, our retinas are packed with many different cell types that help transmit light information to the brain. We know very little, however, about how these cells interconnect, so researchers have turned to mapping and tracing how one cell connects with another…and you can help. A team of scientists at MIT has developed an online game called EyeWire that allows anyone to figure out how cells connect in the retina with real science implications. This image was generated from players correctly tracing connections from one cell to the next, generating a complete connectivity map for these seven cells.

Image by Amy Robinson, Alex Norton, Sebastian Seung, William Silversmith, Jinseop Kim, Kisuk Lee, Aleks Zlasteski, Matt Green, Matthew Balkam, Rachel Prentki, Marissa Sorek, Celia David, Devon Jones, and Doug Bland.

Wiring of retina reveals how eyes sense motion

Online gamers helped researchers map neuron connections involved in detecting direction of moving objects.

A vast project to map neural connections in the mouse retina may have answered the long-standing question of how the eyes detect motion. With the help of volunteers who played an online brain-mapping game, researchers showed that pairs of neurons positioned along a given direction together cause a third neuron to fire in response to images moving in the same direction.

It is sometimes said that we see with the brain rather than the eyes, but this is not entirely true. People can only make sense of visual information once it has been interpreted by the brain, but some of this information is processed partly by neurons in the retina. In particular, 50 years ago researchers discovered that the mammalian retina is sensitive to the direction and speed of moving images. This showed that motion perception begins in the retina, but researchers struggled to explain how.

Read more

08 May 2014

Rainbow Retina

Zebrafish embryos are transparent, making them ideal for studying the formation of complicated cell tissue such as the eyes and the brain. Researchers are currently using a ‘spectrum of fates’ approach in order to learn more about the development of the retina – optical tissue which lines the inside of eyes and communicates with the brain. This technique uses specifically tuned fluorescent proteins to colour-code different cell types. The fluorescent proteins are injected into the yolk of an early-stage zebrafish embryo, where they will track the five major retinal cell types, causing them to fluoresce in a specific colour. Taking images of the retina during its development (pictured) allows the structural formation to be studied in real time – cells can be followed from birth, and around any paths they take before settling into place. Studies like this will improve our understanding of how biological structures initiate and grow.

Written by Helen Thomas

Image by William Harris and colleagues
University of Cambridge, UK
Originally published under a Creative Commons Licence
Research published in Development, April 2014

You can also follow BPoD on Twitter and Facebook

The Social Psychology of Nerve Cells

The functional organization of the central nervous system depends upon a precise architecture and connectivity of distinct types of neurons. Multiple cell types are present within any brain structure, but the rules governing their positioning, and the molecular mechanisms mediating those rules, have been relatively unexplored.

A new study by UC Santa Barbara researchers demonstrates that a particular neuron, the cholinergic amacrine cell, creates a “personal space” in much the same way that people distance themselves from one another in an elevator. In addition, the study, published in the Proceedings of the National Academy of Sciences, shows that this feature is heritable and identifies a genetic contributor to it, pituitary tumor-transforming gene 1 (Pttg1).

Patrick Keeley, a postdoctoral scholar in Benjamin Reese’s laboratory at UCSB’s Neuroscience Research Institute, has been using the retina as a model system for exploring such principles of developmental neurobiology. The retina is ideal because this portion of the central nervous system lends itself to such spatial analysis. 

“Populations of neurons in the retina are laid out in single strata within this layered structure, lending themselves to accurate quantitation and statistical analysis,” explained Keeley. “Rather than being distributed as regular lattices of nerve cells, populations in the retina appear to abide by a simple rule, that of minimizing proximity to other cells of the same type. We would like to understand how such populations create and maintain such spacing behavior.”

To address this, Keeley and colleagues quantified the regularity in the population of a particular type of amacrine cell in the mouse retina. They did so in 26 genetically distinct strains of mice and found that every strain exhibited this same self-spacing behavior but that some strains did so more efficiently than others. Amacrine cells are retinal interneurons that form connections between other neurons and regulate bipolar cell output.

“The regularity in the patterning of these amacrine cells showed little variation within each strain, while showing conspicuous variation between the strains, indicating a heritable component to this trait,” said Keeley.

“This itself was something of a surprise, given that the patterning in such populations has an apparently stochastic quality to it,” said Reese, a professor in the Department of Psychological and Brain Sciences. Stochastic systems are random and are analyzed, at least in part, using probability theory.

This strain variation in the regularity of this cellular patterning showed a significant linkage to a location in the genome on chromosome 11, where the researchers identified Pttg1, previously unknown to play any role in the retina.

Working in collaboration with colleagues at the University of Tennessee Health Science Center in Memphis, Keeley’s team demonstrated that the expression of this gene varies across the 26 strains of mice and that there was a positive correlation between gene expression and regularity. They then identified a mutation in this gene that itself correlated with expression levels and with regularity. Working with colleagues at Cedars-Sinai Medical Center in Los Angeles, the team also demonstrated directly that this mutation controlled gene expression.   

“Pttg1 has diverse functions, being an oncogene for pituitary tumors, and is known to have regulatory functions orchestrating gene expression elsewhere in the body,” explained Keeley. “Within this class of retinal neurons, it should be regulating the way in which cells integrate signals from their immediate neighbors, translating that information to position the cell farthest from those neighbors.” Future studies should decipher the genetic network controlled by Pttg1 that mediates such nerve-cell spacing.

22 July 2014

Retinal Restoration

There’s currently no cure for retinitis pigmentosa (RP), a group of inherited eye diseases that impair the retina’s ability to respond to light, resulting in gradual loss of vision. But now, researchers have used stem cells to develop a promising experimental treatment. First they reprogrammed skin cells from RP patients into stem cells to make patient-specific retinal cells for closer inspection. They found that mutations in a gene called MFRP disrupt the production of actin (red), a protein that provides scaffolding for retinal cells. When this structure doesn’t form properly (left), retinal cells don’t work very well. But when the team used a virus to smuggle in a working copy of MFRP, the structure was restored (right). And in mice with an RP-like condition, the treatment slowly improved vision. It’s early days yet but these results show how patient-specific stem cells can kick start the development of tailor-made therapies.

Written by Daniel Cossins

Image by Stephen Tsang and colleagues
Columbia University Medical Center, USA
Originally published under a Creative Commons Licence (BY 4.0)
Research published in Molecular Therapy, July 2014

You can also follow BPoD on Twitter and Facebook

Motion-Sensing Cells in the Eye Let the Brain ‘Know’ About Directional Changes

How do we “know” from the movements of speeding car in our field of view if it’s coming straight toward us or more likely to move to the right or left?

Scientists have long known that our perceptions of the outside world are processed in our cortex, the six-layered structure in the outer part of our brains. But how much of that processing actually happens in cortex? Do the eyes tell the brain a lot or a little about the content of the outside world and the objects moving within it?

In a detailed study of the neurons linking the eyes and brains of mice, biologists at UC San Diego discovered that the ability of our brains and those of other mammals to figure out and process in our brains directional movements is a result of the activation in the cortex of signals that originate from the direction-sensing cells in the retina of our eyes.

“Even though direction-sensing cells in the retina have been known about for half a century, what they actually do has been a mystery- mostly because no one knew how to follow their connections deep into the brain,” said Andrew Huberman, an assistant professor of neurobiology, neurosciences and ophthalmology at UC San Diego, who headed the research team, which also involved biologists at the Salk Institute for Biological Sciences. “Our study provides the first direct link between direction-sensing cells in the retina and the cortex and thereby raises the new idea that we ‘know’ which direction things are moving specifically because of the activation of these direction-selective retinal neurons.” The study, recently published online, will appear in the March 20 print issue of Nature.

The discovery of the link between direction-sensing cells in the retina and the cortex has a number of practical implications for neuroscientists who treat disabilities in motion processing, such as dysgraphia, a condition sometimes associated with dyslexia that affects direction-oriented skills.

“Understanding the cells and neural circuits involved in sensing directional motion may someday help us understand defects in motion processing, such as those involved dyslexia, and it may inform strategies to treat or even re-wire these circuits in response to injury or common neurodegenerative diseases, such as glaucoma or Alzheimer’s,” said Huberman.

He and his team discovered the link in mice by using new types of modified rabies viruses that were pioneered by Ed Callaway, a professor at the Salk Institute, and by imaging the activity of neurons deep in the brain during visual experience.