As you sip your morning (or afternoon, or evening!) coffee today, check out Scicurious at Scientific American, where I'm talking where caffeine produces its stimulation in the brain. Check it out, and keep sipping! 🙂
Archive for: January, 2012
The word of the week this week is one that many scientists often assume that you already know: presynaptic. But do you? Pre- means before, and it's before the synapse, but what does that mean?
Presynaptic: This is an adjective really, but when I use it, I use it to talk about the neuron that releases the neurotransmitters into a synapse. A synapse (by which I usually mean the synaptic cleft technically) is a space between two neurons, through which chemicals pass to transmit a signal from one neuron to another. The neuron SENDING the signal is considered to be "presynaptic", while the one receiving the signal is "postsynaptic".
This word is very dependent on context. Neurons receive and send information, often in the same area, so whether you are looking at a presynaptic neuron depends on what neurotransmitter or modulator you are looking at, where the signal is coming from, and where it is going. Often a neuron is presynaptic in many places while being postsynaptic in many others, or even within the same signal, as it sends signals back.
One of the best things about being a science blogger is that every day, it seems, I learn something new. I mean, I learned something new most days before I was a blogger, but now, NOW I trawl the internet looking for the things that make you go OMG. And today, I found something that is wild and weird on two different levels.
This, you guys, is the binturong.
The binturong has a couple of cool and odd things about it. The first is that it apparently smells like buttered popcorn. Something to do with their scent glands. I hear that Laelaps is all set to ferret the secret of that out, so I'm focusing on something else odd, but which is actually common to several groups of mammals: teat ownership.
Schoknect, P. "Growth and teat ownership in a litter of binturongs" Zoo Biology, 1984.
For my final wrapup of Science Online 2012, I'm over at Scientific American today, with a storify of the session Lou Woodley and I did on "The Next Generation Science Conference". We talked about adding an online element to conferences, determining what you want from it, and how to get there. Head over to SciAm to check out the storify!
Sci is at SciAm today with a storified wrapup of my awesome session with Kate Clancy at Science Online 2012. We talked about risks that we take in blogging, why we take them, and how we can make sure they are best handled. Participant Marissa was kind enough to put together a storify on the session, and I've posted it over at SciAm, where you can check out how it all went down!
Last week's word of the week was not a sciencey word, but a fun word, because why not? But this word of the week is one I use ALL the time, and one that I always worry people don't know about. And your brain is full of them, so it seems relatively important to know what they are.
Neurotransmitter: These are chemicals that are present in your brain, and serve a chemical messengers between neurons. Neurons do not actually touch each other, instead there is a little gap between one neuron and the next (called a synapse), and neurotransmitters are released from one neuron to the next, to keep a signal going.
An important note: neurotransmitters are released from inside the first neuron (from little bubbles called vesicles which bleb on to the outer membrane of the neuron and release their chemicals out into the space), but they do NOT go into the next neuron. Instead they hit the next neuron and bind to receptors on the cell surface, which change the inside of the target neuron to pass the message on.
Neurotransmitters can cause the next neuron to have an action potential and an excitatory effect, or they can cause that neuron to shut down temporarily, acting in an inhibitory manner. It all depends both on the type of neurotransmitter, and particularly on the RECEPTOR the neurotransmitter binds to. Examples of neurotransmitters include things like acetylcholine, GABA, glutamate, dopamine, serotonin, and norepinephrine (among others). But the chemical itself is merely one molecule, which is released from one neuron and binds to receptors on another. It is then taken up by transporters or degraded by enzymes.
EDIT: I would like to include a note by Dr. Zen (included in a comment below) about the difference between a neurotransmitter and a neuromodulator, which is a very fine one and worth thinking about.
A chemical that has fast, short-lived effect on a neuron is acting as a neurotransmitter. Neurotransmitters bind to receptors that are doorways in the neuron to let electrical current flow.
A chemical that has a slow, long-lasting effect on a neuron is acting as a neuromodulator. Neuromodulators bind to receptors that trigger events inside the cell, but those receptors don’t act as doorways for currents themselves.
The same chemical can be a neurotransmitter in one location and a neuromodulator in another. The same chemical can be acting as both a neurotransmitter AND a neuromodulator on the same neuron, if that neuron has two different kinds of receptors for that chemical on it.
Sea monsters. People are continually fascinated by them. You've got those who believe fervently that there are still undiscovered monsters of the deep, and then you have those who wonder what the monsters we've already sighted...really are. Did someone really see Nessie? Or did they really see something else? And if they saw something else, what is it likely that they saw?
Well, how about a whale. And his penis.
(Is that a sea monster in your pocket or are you happy to see me?)
Paxton et al. "Cetaceans, sex and sea serpents: an analysis of the Egede accounts of a “most dreadful monster” seen off the coast of Greenland in 1734" Archives of Natural History, 2005.
Oh yes, there are pictures below the fold. You know you want to look.
Since I first saw a post by Jesse Bering, responding to a question by a “Deep Thinking Hebephile”, I have wished to write a response of my own, covering more of the literature on the subject, and clarifying some points. It’s taken a while to gather my sources. For starters, I do not think that Jesse intended to, explicitly or implicitly, condone hebephilia. But this is where taking risks in scientific writing can lead to unintended consequences, and where choosing the wrong words, failing to adequately define the right ones, and mixing it all up with a lack of context and a paucity of references can produce a very unfortunate result. So I’d like to tackle this issue a little bit myself, from all the angles that were questioned in the original piece, with a few more sources, and a lot more context. This topic dovetails quite nicely with my upcoming Science Online discussion section with Kate Clancy, on writing about sex, and the line between education and titillation.
Lou Woodley and I are very excited for our Science Online 2012 session on "The Next Generation Science Conference". We'll be talking about how scientific societies can get online, how and whether to use your online presence as a society for outreach, and how societies and bloggers can help each other out. Check it out and please think about attending! We're totally excited to crowdsource some ideas!
Sci is at Sci Am today, sharing part of my blog origin story, as part of a description of what my session with Kate Clancy will be about at Science Online 2012. We will be talking about taking risks in science blogging, what it means, and what our responsibilities are. And of course, we'll be talking about why we take those risks in the first place. To help jump start the conversation, I have shared part of my blog origin story, to describe some of the tension I feel when I blog and what the risks are that I take. Go over and check it out!