[offtopic] Fab labs

Totally offtopic but cool.


Rehmi Post is just wrapping up his PhD. Among other things, he teaches a three month class to new students, titled “how to fabricate (almost) anything”. Students start with using CAD packages, then he takes them through fabrication of parts using machine tools, how to design circuit boards, and — literally — just about anything, up to and including MEMS, microelectromechanical machines etched out of silicon wafers using the same lithography techniques as microprocessors. “One thing we’ve learned in the course of this study is that the fabrication tools currently available all suck,” he says.

Which is why he and some other researchers are working on the Fab Lab. The goal is to build a toolkit that can be sold for under $10,000 (£6500) and that contains everything you need in order to make almost anything. “We want to take arts and crafts to a level where people can do their own prototyping, build their own radios, oscilloscopes, or computers, and do it on the cheap with full support in tools and hardware.” He’s not kidding. The Fab Lab — personal fabrication — includes a CAD workstation, a modified vinyl cutter able to carve circuit boards, a computer-controlled milling machine, an FPGA programmer, and may eventually include a 3D printer and other machine tools. One important element they’re working on is a library of electronic components, royalty-free, than the system can be used to handle various tasks. Using FPGA (field programmable gate array) chips means the system can contain sophisticated electronics — FPGAs are designed to be reconfigured at the hardware level to emulate arbitrary circuits, all the way up to an ARM processor. The Fab Lab team are trying to develop a system comprehensive enough that any one Fab Lab can be used to build copies of itself, and they’re looking at a hardware design strategy akin to the GPL (GNU General Public License) — spin offs such as Project Pengachu give a feel for how they’re thinking these tools can be used.
” — article by Charlie Stross on MIT Media lab

links:

http://fab.cba.mit.edu/

http://cba.mit.edu/projects/fablab/index.html

according to http://fab.cba.mit.edu/info.html, a fab lab currently
costs about $30k; i’m assuming it’s not self-machinable yet.

Cell-chip adhesion chemistry

Berkeley researchers lay groundwork for cell version of DNA chip

This is a little off the beaten path, but I think that the Neurodudes crowd is generally interested in techniques related to neuron-to-silicon interfacing. Here’s some neat surface chemistry from Livermore Labs that facilitates binding of DNA oligos to the cell surface. Then, just like with a gene chip, you can link cells with the right (complementary) oligos to a pre-coated chip.

My first reaction to this was, Wow, another great application of the homologous base pairing machinery of nucleic acids. I’m amazed by the out-of-the-box thinking in this idea — sticking DNA to the outside of the cell. According to the article, the authors estimate that about 270,000 DNA molecules are put on the surface of each cell by their process. (Though I’m sure they’ve looked at it, one does wonder how this impacts membrane trafficking, receptor internalization processes, etc.)

Let me emphasize… This is totally cool! This allows cell-type-specific micropatterning at the level of whatever your chip printing resolution is. (Traditionally, gene chips are “spotted” using precision multi-head inkjet-like printers.) For you cell culture enthusiasts out there, you might imagine a cell culture where you have many different cell types and have full control (down to a single cell!) of where each type of cell is placed. Talk about a co-culture!

Neonatal Antidepressant Exposure has Lasting Effects

Neonatal Antidepressant Exposure has Lasting Effects on Behavior and Serotonin Circuitry [Neuropsychopharmacology]

Since we’ve had some articles on SSRIs before, I thought I’d add this one.

Here’s the central result:

In neonatal rodents, chronic administration of serotonin reuptake inhibitors (clomipramine, fluoxetine, zimeldine, LU-10-134C) as well as some other tricyclic antidepressants but not the atypical antidepressants iprindole or nomifensine during the early life period from postnatal day 8 (PN8) to PN21 results in a pattern of maladaptive behaviors that are evident long after drug discontinuation and persist into adulthood (Mirmiran et al, 1981; Hilakivi et al, 1984; Hilakivi and Hilakivi, 1987; Hansen et al, 1997; Ansorge et al, 2004). These behavioral changes, described here as the ‘neonatal antidepressant exposure syndrome (NADES)’, in rats include alterations in locomotor activity, reduced male sexual activity and competence, increased ethanol consumption, dysregulation of the hypothalamic-pituitary-adrenal axis, increased rapid eye movement (REM) sleep time and reduced latency to enter the REM sleep phase, and increased immobility in the forced swim test (Mirmiran et al, 1981; Hilakivi et al, 1984; Hilakivi and Hilakivi, 1987; Hartley et al, 1990; Hansen et al, 1997). In contrast, adults exposed to similar doses and durations of antidepressants exhibit no persistent behavioral effects after drug discontinuation, indicating that the neurobiological response to long-term antidepressant administration differs markedly between early life and adulthood.

These findings indicate that there is some early (in development) regulation of the 5HT system. Without “proper” development, the organism suffers long-lasting deficits, but if the 5HT system is exposed to modulatory SSRIs later in life, there are no long-term changes. Interesting. I wonder what developmental switches (genes, etc.) are responsible for this difference.

much-needed list

I’ve been thumbing through pubmed, online resources, and lab members’ collective consciences looking for a complete list of pharmacological agents acting on receptors (i.e. metabotropic glutamate receptors), phenomena (i.e. AMPA receptor desensitization), and any other players that can affect neurotransmission at the synapse. No such list seems to exist.

So, if you have some knowledge to contribute, please add to this list of agents and effects on a new wiki page. Warning: the current format is really simple (any improvements would be welcome), but it’s a first pass at a much needed electrophysiology resource.

— davematthews

of wikis and wizards

This week’s Nature features an idea called “The Digital Universe,” which hopes to organize and present peer-reviewed content (especially science) for public consumption online.
Preview the actual site here .

There’s some important criticism, especially of the business model, in the article…and you have to wonder about the creator, a wiki-disser and alien-watcher: “The driving force behind the project is ManyOne, a company headed by Joseph Firmage, who made a fortune in the 1990s from an Internet consulting company. He resigned in 1999 after the fallout from his book claiming that he had encountered extraterrestrials. Firmage says he vehemently opposes the ‘anyone can edit’ vision of Wikipedia. ‘Wikipedia is a very uninviting place for most intellectuals,’ he adds.”

-davematthews