It Shifts

The Birth of Brain Cells

This might look like a distant web of galaxies captured by a powerful telescope, but it’s actually a microscopic image of a newborn nerve cell. The human brain contains more cells than there are stars in our galaxy, and the most important cells are neurons, which are nerve cells responsible for transmitting and processing electro-chemical signals at up to 320 km/h. This chemical signalling occurs through synapses—specialised connections with other cells, like wires in a computer. Each cell can receive input from thousands of others, so a typical neuron can have up to ten thousand synapses—i.e., can communicate with up to ten thousand other neurons, muscle cells, and glands. Estimates suggest that adult humans have approximately 100 billion neurons in their brain, but unlike most cells, neurons don’t undergo cell division, so if they’re damaged they don’t grow back—except, apparently, in the hippocampus (associated with memory) and the olfactory bulb (associated with sense of smell). The process by which this occurs is unclear, and this image was taken during a project to determine how neurons are born—it actually depicts newborn nerve cells in an adult mouse’s brain.

(Image Credit: Dana Bradford)

Who doesn't love a good ole PAS stain?

Ft some lovely Cryptococcus organisms

Life has been busy and stressful and very very strange but at least pathology can always be depended on - please enjoy this weird and invasive mammary carcinoma from a dog.

The many faces of reactive plasma cells - all found within the same chronic skin infection in a dog!

Plasma cells are activated B lymphocytes and their purpose is to secrete immunoglobulin. When they become reactive, or stimulated, they can be binucleated, multinucleated, and have a variety of morphological changes occur including the formation of Russell bodies. Russell bodies are round to globular intracellular aggregates of immunoglobulin; their formation is due to an imbalance between the rates of synthesis, folding, secretion, and degradation of immunoglobulins.

While most Russell bodies are rounded, one (of many) phenotype of Russell bodies can present as crystalline bodies. Immunoglobulin crystals are very uncommon to see in plasma cell proliferations, and very few reports have been authored on them in veterinary medicine. I feel very lucky to have found three different types of crystalline bodies as you can hopefully appreciate in the above pictures!

Pleural fluid - cytospin slide stained with wrights stain - lung cancer

It's still so weird to me that this is what a bacteriophage actually looks

Like, tf do you mean it's not just a diagram, and it really looks like this

the lichen knowledge iceberg i have constructed on request

Type B orcas surfacing

Natgeo

Some of you may be familiar with model organisms in biology but even so, you may think about mice, rabbits or flies rather than ctenophores. The whole purpose of having a model organism is to be able to understand particular biological functions/processes by using an organism that can be maintained easily, has a relatively short generation time and has its genome sequenced (this allows us to really understand their genetic makeup). Since this species of ctenophore (Mnemiopsis leidyi) has had its genome sequenced it allows us to identify key genes/proteins and try to determine their function.

The work I am currently doing for my project is focused on understanding the origin of the nervous system.

There's been a long standing debate amongst scientists over which species of animal first diverged from all other metazoans whether it be sponges or ctenophores. For a long time it has been thought that sponges are the sister group to all metazoans, although more recently studies have suggested that ctenophores are. Sponges are really simple animals that lack nervous systems, whereas ctenophores are more complex and have a nervous system. If ctenophores are then in fact found to be the sister group to all other metazoans, it poses the questions about whether the complex structures such as neurons and synapses evolved once or multiple times independently?

If you check you can see a diagram showing what I mean by the "sister group" to all metazoans. The first pic identifies sponges as the sister group, but with more analysis on a molecular basis, the 3rd pic could be possible.

Since most of the studies on neurons and nervous systems more generally are focused on metazoans, the work at this lab uses ctenophores to understand more about their complex biology with the aim of understanding the origins of neurons.