Quickie – Considerations of in vivo electrophysiology

I’m just reading a paper on the response properties of monoamine neurons, and it starts out with a few points of consideration for electrophysiological recording of neurons in vivo. I thought I’d relay them here.

1. The evidence that you are recording from a given type of neuron (dopaminergic, serotinergic etc.) is almost always indirect. It is usually based on electrophysiological characteristics determined by previous in vitro studies, using intracellular recording and neuron staining.
2. We can describe the general behaviour of a group of neurons which contain/release a particular neuron, as they often appear to behave in a homogenous manner. Jacobs notes “this may change, of course, as more detailed analyses are carried out.” The paper was published in 1986, and for my neuron of interest – dopaminergic neurons – this has indeed changed.
3. In order to properly understand the activity of a neuron, it has to be recorded from an unanesthetised animal, as beyond the advantage of being able to study behaviour and neural activity, anaesthesia can profoundly affect neuronal responses.

There’s also a nice little Q&A after the references, which seems quite quaint. It’s nice to read older papers to give a general overview of a subject before diving into the nuanced modern research, you just have to make sure it’s not so old as to be totally misguided and out of date.

JACOBS, B. (1986). Single Unit Activity of Brain Monoamine-Containing Neurons in Freely Moving Animals Annals of the New York Academy of Sciences, 473 (1 Neurochemical), 70-77 DOI: 10.1111/j.1749-6632.1986.tb23604.x

I’m learning about bees!

Just on my way home from my second day as educational resource assistant for a project to encourage people to keep bees. My job involves creating educational materials for primary schools to accompany the project and highlight the plight of bees. This means I’ve spent the last couple of days reading the kind of thing that already goes out to schools, and reading lots of interesting things about bees.
Unfortunately, most of the stuff that I’m finding most interesting probably isn’t as relevant to the ecological importance of honey bees. Like how they don’t just have regular old dull compound eyes like I thought they did, but that they’ve also got three simple-lens ocelli, which are only really sensitive to light, and have been suggested to be part of some sort of orientation mechanism. Or that they don’t have centralised brains, but instead just have bunches of nerves down their body. Or that they can not only detect colour and patterns, but are capable of remembering them reasonably well several days after just one exposure, and almost perfectly after three! Or that their sting evolved from the ovipositor, but in some species it’s in a weird halfway stage where the sting is more like a sword.
The irreplacable role of bees in the economy, and more importantly the environment is probably easier to pitch as a classroom topic to primary school teachers, but I’m getting into it, and it seems a shame for it to go to waste.
So expect some bee related science over the coming few months. I’ll try and keep it neurosciencey…

Scatterplot matrices and MANOVA in R

I’ve got a deadline to get one of my thesis chapters drafted by the end of the week. It was the end of last week, but all the unemplyment and job seeking stuff got in the way, and the analysis has been a little bit harder than I expected, so it got pushed back (oops, guess I should be used to that by now).

Anyway, I’ve been doing some of the analysis in R, and I thought I’d stick it up here to get some tips/feedback. Please bear with me on the state of the figures, they’re a bit sketchy at the moment.

Click ‘More’ for tedious technicalities!