When the stress gets too much

It’s not easy being an electrophysiologist. Most of the time we’re under a lot of pressure and not just from our supervisors and managers, but from ourselves too. Sometimes we go for weeks, even months, without a single successful experiment. We know that it has worked for us before, but now that that all important deadline is coming up, electrophysiology refuses to play ball.

Very true

Very true

When asked “what’s wrong?”, most of the time the answer will be “I just don’t know”. This is not because electrophysiologists are lazy and have no idea what they’re doing. On the contrary, we’re very acutely aware that many, many different things have to be just right in order for an experiment to work – and sometimes even that is not enough.

Disaster can strike at any time

Disaster can strike at any time

Going through the list of things that have to be absolutely perfect can be time consuming, but any electrophysiologist worth their salt will have a vague idea of what the weak links are likely to be.

Some days are a bit 'meh'

Annoying

Some days the electrodes  are not absolutely perfect

Sometimes the problem can be really obvious.

Another experiment ruined and a day wasted

My experiment may not have worked, but I do enjoy a bit of DIY

I hate it when the perfusion system doesn't co-operate

Occasionally stress can be released in the form of exclamation marks and profanities.

Sometimes the tools you work with can let you down and spoil your day

And right after I put on some drugs too

Sometimes it's the computer program that can let you down

But when the stress gets too much, sometimes the best thing to do is walk away, have a cup of tea and calm down.

Next time you see an electrophysiologist alone in the corner with a cup of tea, approach with caution

Next time you see an electrophysiologist alone in the corner with a cup of tea, approach with caution

 

Be careful! Sometimes pent up stress can erupt when you least expect it:

A group of PhD students were in the breakout space one afternoon, taking a break from work. Everyone was happily chatting away and conversation turned to favourite Family Guy sketches. Someone quoted a particularly funny phrase and everyone laughed. One person in particular laughed so hard, he could barely breathe. Everyone starts laughing again and this time two more people laughed so much that they struggled to speak. The uncontrollable laughing continued, but not everyone was doing it anymore. Only three people were laughing, but their sounds of laughter started to sound more and more like sobs. There was a bit of an awkward silence and one by one people started to leave and return to the lab. The PhD students wiping their eyes and taking deep breaths looked round at each other and realised that they were electrophysiologists.

Like I said before: if we didn’t laugh, we’d cry and believe me, we’ve cried a lot.

You have been warned

 

For the love of brain (well, the hippocampus) II

So I’ve already described how much I love being able to look at live, functional neurons in real time. But there are other things I enjoy seeing everyday too, in particular my favourite part of the brain; the hippocampus.

The rodent hippocampus in stained, coronal sections

The rodent hippocampus in stained, sequential coronal sections

At the start of every patch clamp experiment, when I look down the microscope at a brain slice, I need to locate a specific structure before I can focus on finding individual neurons. This structure is called the hippocampus (so called because a cross section of it looks like a seahorse) and every brain has a pair of them (one in each hemisphere). The hippocampus is very special because it has a well-defined and distinctive structure, which makes it instantly recognisable to anyone who has studied neuroanatomy.

Freshly cut transverse brain slices. I store them in a plastic tea strainer, submerged in  carboxygentated aCSF. The arrow points to where the hippocampus is loacted

Freshly cut transverse brain slices. I store them in a plastic tea strainer, submerged in carboxygentated aCSF. The arrow points to where the hippocampus is located

 

Acute, transverse hippocampus as seen during my patch experiments - notice the patch electrode emerging from the CA1 region in the right-side image

Acute, transverse hippocampus as seen during my patch experiments – notice the patch electrode emerging from the top of the CA1 region in the image on the right

As I’ve said before, the brain is not a homogenous blob, but contains many intricate and beautiful structures. Many of these structures look pretty much the same across the majority of species, no matter what size or shape the brain may be, and the hippocampus is no exception.

Drawing by Camillo Golgi of a hippocampus stained using silver nitrate

Drawing by Camillo Golgi of a hippocampus stained using silver nitrate

Why do I love the hippocampus? Well, for one thing I love how ‘organised’ the anatomy is (I won’t go into detail here, but I do find the Wikipedia page extremely useful). The hippocampus is a network and I love how you can stimulate a particular pathway and get other neurons to fire in response (ie. stimulate the axons of the CA3 pyramidal neurons and the CA1 pyramidal neurons will produce a response). I also love the fact that it’s involved in lots of different aspects of learning and memory.

So, going back to the point about being able to stimulate pathways in the hippocampus, I also do a lot of experiments using multi-electrode arrays (MEAs). Being able to stimulate particular pathways and measuring evoked responses can tell you a lot about the synapse involved and the neurons on either side. For my experiments, I stimulate the Schaffer collaterals (axons of CA3 pyramidal neurons) and record the responses of the CA1 pyramidal neurons. Instead of observing signals from individual neurons, I look at the combined response of a whole population of neurons, which all fire in unison when stimulated by an extracellular electrode.

I take a photograph (before and after!) of every hippocampus I use for my MEA experiments. It allows me to select which electrodes to stimulate so that I can record evoked field potentials

I take a photograph of every hippocampus I use for my MEA experiments so that I can select which electrodes to stimulate in order to produce evoked responses. This is not a stained section – it’s the actual colour of a ‘living’ hippocampus!

I’d love to go into more detail about MEA experiments, but I’ll save it for another post 🙂