AANP 2012: Dr. Michael Norenberg talks about the multifunctionality of astrocytes



Dr. Norenberg on "Why the Brain Fails when the Astrocyte Ails"

The University of Miami's Michael Norenberg is currently talking about the functions and physiology of astrocytes. The forgotten function of astrocytes is that they are involved in the synaptic communication between neurons and are an active participant in modulating the neuron-neuron interaction. Dr. S. Ramon y Cajal speculated on this active participation of the astrocyte in the synapse with regard to sleep many decades ago. So, although not a new concept, the concept of expanded functionality of astrocytes has gained scientific support in recent years.

Neuropathologists party hard at this evening's AANP annual reception

L to R: Drs. Heather Sumner and T. David Bourne

Drs. Mark Cohen, T. David Bourne, and Mahtab Tehrani

L to R: Drs. Edward Stopa, William Taylor, and Qian Wu

AANP's "Special Course" is Underway

I am currently in attendance at the American Association of Neuropathologists Annual Meeting special course entitled Acquired Neuropathology in a Changing World. A crowd of more than 300 attendees are present. Dr. Leroy Sharer recently finished his presentation, entitled "AIDS Neuropathology - A 30 Year Perspective", which provided a unique insight into the evolution of our understanding of HIV in the CNS.

Dr. Sharer sharing his persepctive on AIDS neuropathology this morning

Meanwhile, the accomodations at The Palmer House Hotel here in Chicago are magnificent.

Detail from ceiling of the lobby at Chicago's landmark Palmer House Hotel

Yasser Lopez: A Modern-Day Phineas Gage

Above is an x-ray released yesterday by Jackson Memorial Hospital in Miami, Florida depicting a spear entering the head, traveling through the brain, and piercing the opposite skull surface of 16-year-old Yasser Lopez. The boy is on the road to recovery after being accidentally shot in the head while loading a speargun with a friend earlier this month

"It was about one inch above his right eye straight through," said trauma surgeon Dr. George Garcia. "You could feel the tip under the skin on the posterior part of the skull."

"The most important thing is to resist that temptation to pull the thing out," neurosurgeon Dr. Ross Bullock said. Bullock and his trauma neurosurgeon team determined the tip of the spear inside Lopez's head was actually a screw tip. "It was possible for us to figure out a strategy during the operation to be able to unscrew the tip of the spear, instead of having to get this whole spear dragged out through his brain," Bullock said.

Bullock said Lopez can speak normally. "He can, for example, he says he's not having pain. He's worried about the fact he can't use his left-side properly."

Lopez's story brings to mind that of Phineas P. Gage, whose left frontal lobe was obliterated by a railroad spike that exploded upward when he was tamping it down in 1848.

Phineas P. Gage (1823-1860)

As for the day he got shot, Lopez knows nothing. Doctors expect him to make a near-full recovery.

Read more here: http://www.miamiherald.com/2012/06/18/2856543/doctors-miami-dade-teen-shot.html#storylink=cpy

Best Post of January 2012: The area postrema is not the only area where the BBB is lacking

The next in our "Best of the Month" series comes from January 9, 2012:

I'll paraphrase a question posed by one of my 2nd-year students at Southern Illinois University School of Medicine:

I understand that the Area Postrema was a site where there was increased penetrability of the blood brain barrier. I am not sure, but thought I had come across additional sites of increased penetrability last year in my reading. Are there other sites where there is increased permeability of the BBB?

 

In pondering an answer to this question, I immediately thought of the illustrious Dr. John Donahue, consummate neurologist, neuropathologist, and neuroanatomist.  I posed the question to him and got the following response:

Dr. John Donahue, Brown University, Providence, RI

"Not increased permability of the BBB.  NO BBB!  Area postrema is one of the circumventricular organs, areas in the brain that lack a BBB.  Being the vomiting center, it is imperative that it lacks a BBB so that it can sample the systemic circulation.  Being in the medulla, it is the only circumventricular organ that is adjacent to the fourth ventricle; all of the others are adjacent to the third.  It is the only paired circumventricular organ; all of the others are single and midline.  The other circumventricular organs are subfornical organ, organum vasculosum of the lamina terminalis, median eminence, posterior pituitary gland, subcommissural organ, and pineal gland."

 

There you have it!

2,000 players unite in suing NFL over head injuries

CNN reports today that a unified lawsuit on behalf of more than 2,000 National Football League players has been filed against the league in federal court, alleging that the NFL failed to acknowledge and address neurological risks associated with the sport and then deliberately failed to tell players about the risks they faced. The complaint unites the more than 80 pending lawsuits filed against the NFL.

Lawyers representing the players cited "dementia, depression, reduced cognitive ability, sleeplessness, early-onset Alzheimer's, and a debilitating and latent disease known as chronic traumatic encephalopathy" as some of the specific injuries caused by head trauma in the NFL.

Thanks to Dr. Jeff Bennett for alerting me to this story.