Archive for the ‘Neuroscience’ Category
Dormivigilia’s “Official” Website
November 18, 2009
Neury Thursday: Once Again, Glia Do It ALL
November 13, 2009
A few months ago, I reported about the role of glia on the mediation of the homeostatic drive for sleep/wake. Glia additionally mediate the neurochemical environment and the immune response after it’s primary purpose: structural support. According to a recent Journal of Neuroscience article, radial glia in the tectal visual areas mediate the visual experience; radial glia interact with synaptic activity during the activation of nitric oxide and other downstream N-methyl-D-aspartate (NMDA) receptors of the visual circuit. It’s no surprise that that activation of NMDA and NO are also critically important to shift behavioral sleep/wake rhythms through light.
Below is a psychedic photomicrograph capturing the activation of radial glia at three different time points, demarcated by color.Totally awesome, dude.
Neuroscience Journal Club: Green Anole ER-alpha expression
November 10, 2009
In our bi-weekly Journal Club, soon-to-be Master Phillip Long presented an article on seasonal variation in ER alpha dimorphism in green anole. Estradiol (E2) binds to ER-alpha or estrogen receptor-alpha to mediate male reproductive behaviors and female receptive (i.e. give it to me, baby) sexual behaviors. E2 is also responsible for brain masculination. Imagine how this information could change current and past male-female societal expectations! Anyways, back to science. In the paper discussed, male and female anoles were captured during their breeding and non-breeding seasons (May and October, respectively) and brought into the lab to assess ER-alpha expression in various brain regions. Regions of high ER-alpha expression include the ventromedial hypothalamus, medial preoptic area, and the ventromedial amygdala. This is no surprise give that these brain areas mediate sexual dimorphism of the brain and behavior. Other areas with marked ER-alpha expression include the septum which mediates aggression (is this the neurobiological etiology of S&M?!), the suprachiasmatic nucleus which I imagine regulates seasonal breeding, and the nucleus accumbens which mediates reward (again, again!).
Though there were many questionable methodologies within the paper, which led me to believe it was an undergraduate research project (no offense), it certainly is interesting to find differential expression of ER-alpha in a reptilian model that is comparable to ER-alpha expression in mammalian and avian models. Neuroscience rocks.
Below is a video of a male green anole courting a female. When anoles court, they distended their dulap (vibrant bright orange pouch below their jaw) and bob their head. I had the opportunity to see this while wandering around the Costa Rican cloud forests. It’s awesome.
Red Bull vs. Sleep
November 9, 2009
Taurine is a protective mechanism, however, against ethanol intoxication and ethanol-induced apoptosis.
Neury Thursday/Friday: Coloring in V4
November 6, 2009
I apologize for the delay of Neury Thursday, but last night, I went to a Kent State Freethinkers meeting on the secrets/tricks/talent of mind reading. You can watch the six part series featuring Derren Brown, an English illusionist, and Richard Dawkins. The “artistic” camera shots are quite irritating, but it’s worth the content.
Back to neuroscience, in this week’s Journal of Neuroscience, scientists used functional magnetic resonance imaging to decode and reconstruct the perception of color within the visual cortex, specifically area V4. I’m not sure of the functional significance of the front cover illustration, but perhaps someone more versed in the visual system will tell. It reminds me of the color wheel posted on the blackboard in art class, illustrating that various perceived colors such as maroon, aquamarine, and even macaroni n’ cheese are simply synthesized from primary (blue, red, yellow) and secondary (green, purple, orange) colors.
Halloween + Fall Back
October 31, 2009
Tonight is Halloween. Kent State has one of the largest Halloween celebrations in the country. And tomorrow, we will all get an extra hour of sleep to nurse off those hangovers. It’s Daylight Savings. Daylight Savings was initiated by Benjamin Franklin to reserve candle wax.
Now back to hangovers. At yesterday’s lab meeting, the boss, Dr. D. Glass, was telling us about a recent Mythbusters episode where they dissected the common adage of “beer before liquor never been sicker” and “liquor before beer in the clear.” Apparently, the cast of Mythbusters discovered the hard way that drinking beer all night results in unbearable hangovers.
I heart science.
Hollah to Gagan!
October 30, 2009
Today, my lab mate, Gagandeep Kaur successfully defended her dissertation: “Phase regulation of the circadian clock: neuropeptidergic and serotonergic mechanisms.” You can read about figments of her dissertation in a recently published article investigating rapid circadian re-entrainment to a new photocycle (i.e. time zone) following brief, constant light exposure and systemic administration of serotonergic agonists. The administration of serotonergic agonists (i.e. antidepressants) advances circadian rhythms by means of advancing the time of activity onset. When exposing nocturnal animals to constant conditions of light, the extent of advance of activity onset is potentiated.This type of accelerated re-entrainment would be beneficial for travel to far time-zones.
Dr. Kaur is off to work at a nearby veterinary clinic, applying her circadian experience towards better veterinary animal care.
Neury Thursday: GABA-ific Glomerulus Gating
October 29, 2009
In the week’s Journal of Neuroscience, an artistic rendition of the weekly featured article was illustrated by Greg Dunn of UPenn. GABA-ergic projectoins have been found to gate glomerulus neuronal activity, hence gating olfaction.
Another article in this week’s journal characterized the rrecruitment of motor and interneurons critical for swimming in the zebrafish, which surprisingly begins early during embryonic development. Fast and strong neurons are recruited first (I’m guessing they are large, myelinated neurons with many dendritic arborizations) followed by the weaker and slower neurons (smaller, myelinated and/or non-mylineated, unipolar and/or bipolar).
What do Football and Dogfighting have in common?
October 26, 2009
Brain damage. In a recent issue of The New Yorker, a “Yuppie” magazine to which I describe, there is a fantastic article on irreversible, irreparable brain damage associated with sports injuries. A few months ago, I posted a similar article from Science. In this particular New Yorker article, the neuroscientists who autopsied the brains of ex-football players/boxers were able to delineate between dementia related to aging/Alzheimer’s and dementia related to chronic head-bashing; the former is characterized by accumulations of both amyloid beta-protein and tau, while the latter is discernible only through tau neurofibrilliary tangles.
But where does dog fighting fit? In addition to dementia, head injuries and excessive head-bashing (1,000 hits per football season alone!) greatly predispose athletes to substance abuse, depression, and violence. And clearly, it takes a violent person, a person who can dissociate themselves from another’s pain and suffering, to watch two dogs maul each other to the death for money and/or euphoria.
The author of the piece talks about the subject in a captivating slide show that exemplifies the neurodegeneration caused from too many hits in the head.
Neury Thursday: Fly/Post-Flight Neck Spasms
October 23, 2009
In this week’s Journal of Neuroscience, scientists recorded membrane potentials from fly neck motor neurons. I bet that you would have found similar membrane potentials in my neck motor neurons after accidentally falling asleep on the plane ride home from SfN. Why couldn’t any of the exhibitors hand out neck rests?! I guess 5 grocery hippie bags, 3 USB Flashdrives, 2 mugs, pens and pencils, and a laptop sleeve isn’t too much to expect….