Thursday, November 29, 2007

Neuropsychology Abstract of the Day: Epilepsy

Meador KJ, Gevins A, Loring DW, McEvoy LK, Ray PG, Smith ME, Motamedi GK, Evans BM, & Baum C. Neuropsychological and neurophysiologic effects of carbamazepine and levetiracetam. Neurology. 2007 Nov 27; 69(22): 2076-2084.


Department of Neurology, University of Florida, McKnight Brain Institute (L3-100), 100 South Newell Drive, Gainesville, FL 32610, USA.

BACKGROUND: The relative effects of levetiracetam (LEV) and carbamazepine (CBZ) on cognitive and neurophysiologic measures are uncertain. METHODS: The effects of LEV and CBZ were compared in healthy adults using a randomized, double-blind, two-period crossover design. Outcome measures included 11 standard neuropsychological tests and the score from a cognitive-neurophysiologic test of attention and memory. Evaluations were conducted at screening, baseline pre-drug treatment, end of each maintenance phase (4 weeks), and end of each washout period after drug treatment. RESULTS: A total of 28 adults (17 women) with mean age of 33 years (range 18 to 51) completed the study. Mean maintenance doses (+/-SD) were CBZ = 564 mg/day (110) and LEV = 2,000 mg/day (0). CBZ was adjusted to mid-range therapeutic level. Mean serum levels (+/-SD) were CBZ = 7.5 mcg/mL (1.5) and LEV = 32.2 mcg/mL (11.2). An overall composite score including all measures revealed worse effects for CBZ compared to LEV (p less than/or= 0.001) in the primary analysis and for CBZ (p less than/or= 0.001) and LEV (p less than/or= 0.05) compared to non-drug in secondary analyses. Across the 34 individual variables, CBZ was worse than LEV on 44% (15/34); none favored CBZ. Compared to the non-drug average, CBZ was worse for 76% (26/34), and LEV was worse for 12% (4 of 34). Sensitivity and specificity of standard neuropsychological tests and the cognitive-neurophysiologic test were determined to direct future studies; detection was most accurate by the cognitive-neurophysiologic test. CONCLUSIONS: Levetiracetam produces fewer untoward neuropsychological and neurophysiologic effects than carbamazepine in monotherapy at the dosages and timeframes employed in this study.

PMID: 18040014 [PubMed - in process]

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Diversity Program in Neuroscience Fellowship

From the American Psychological Association:

GRADUATE FELLOWSHIPS
IN PSYCHOLOGY AND NEUROSCIENCE

Do you want to take charge of your career? Do you need financial support for graduate school or postdoctoral studies? Are you interested in ethnic minority issues? Then the Minority Fellowship Program is for you!

The Minority Fellowship Program (MFP) offers the following fellowships

The Mental Health and Substance Abuse Services (MHSAS) Fellowship is aimed at those pursuing doctoral degrees in clinical, counseling, and school psychology, or other mental health services areas. This program is primarily for individuals who want to deliver services.

The MHSAS Postdoctoral Fellowship is aimed at early career doctoral recipients who are interested in developing a career in mental health service delivery, policy, or services-related research.

The Diversity Program in Neuroscience Fellowship is geared to those pursuing careers in neuroscience. Predoctoral and postdoctoral fellowships are offered. Doctoral students or early career doctoral recipients in psychology or any life science discipline related to neuroscience may apply.

Note: Individuals may apply to only one of the MFP fellowships.

The application deadline is January 15.

About the Minority Fellowship Program
The MFP’s mission is to increase the knowledge and research related to ethnic minority mental health and to improve the quality of mental health and substance abuse services delivered to ethnic minority populations. We do this by providing financial support, professional development activities, and professional guidance to students pursuing doctoral degrees in psychology and neuroscience. Our mission is consistent with Healthy People 2010, the Surgeon General’s Report on Mental Health, and other federal initiatives to reduce health disparities.

For more information or to apply for a fellowship, visit our web site at www.apa.org/mfp or contact us at:

APA/MFP
750 First Street, NE
Washington, DC 20002-4242
(202) 336-6127
Email: mfp@apa.org

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Monday, November 26, 2007

Calling All Iowans: Alzheimer's Disease

From the Radio Iowa website:

Task force seeks public input on Alzheimer's disease
Monday, November 26, 2007, 8:46 AM
By Pat Curtis

"A task force in Iowa that's looking for ways to improve services to Alzheimer's patients is asking for your help. John McCalley, director of the Iowa Department of Elder Affairs, says all Iowans are invited to take an on-line survey.

He says the survey is mainly designed for Alzheimer's patients and their family members or care givers. McCalley, who also chairs the 17-member Alzheimer's disease Task Force, says the state's current services to dementia patients are somewhat uncoordinated. He says funding is provided to Area Agencies on Aging across the state, but those services face limited funding, especially in rural areas.

An estimated 65,000 Iowans have Alzheimer's disease and that number is expected to grow as Iowa's population ages. McCalley says the survey only takes 5 to 10 minutes to complete. He says the questions on the survey allow individuals to document their experiences with Alzheimer's and suggestions for improving Iowa's services.

McCalley says he'd like the surveys completed by December 10, so his group can compile a report and present recommendations to the Iowa Legislature in January."

===

The online survey for Iowans can be found as a link on the Radio Iowa webpage linked to above.

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Sunday, November 18, 2007

Love and Alzheimer's: Sarah Polley's Away From Her and Sandra Day O'Connor

Love in the Time of Dementia
By KATE ZERNIKE
Published: November 18, 2007
The New York Times

Kudos to the headline writer for the reference to Love in the Time of Cholera, the wonderful book, which after twenty years has now been released as a movie. Kudos also to Kate Zernike for this wonderful first line to her piece in today's Times:

"So this, in the end, is what love is."

[ ... Read the full piece ... ]

Away from Her.

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Thursday, November 15, 2007

Neuropsychology Abstract of the Day: Attention

Pattyn N, Neyt X, Henderickx D, & Soetens E. Psychophysiological investigation of vigilance decrement: Boredom or cognitive fatigue? Physiology and Behavior. 2007 Oct 3; [Epub ahead of print.]

Department of Cognitive & Biological Psychology, Vrije Universiteit Brussel, Pleinlaan, 2, 1050 Brussel, Belgium; Department of Behavioral Sciences, Royal Military Academy, Renaissancelaan, 30, 1000 Brussel, Belgium.

The vigilance decrement has been described as a slowing in reaction times or an increase in error rates as an effect of time-on-task during tedious monitoring tasks. This decrement has been alternatively ascribed to either withdrawal of the supervisory attentional system, due to underarousal caused by the insufficient workload, or to a decreased attentional capacity and thus the impossibility to sustain mental effort. Furthermore, it has previously been reported that controlled processing is the locus of the vigilance decrement. This study aimed at answering three questions, to better define sustained attention. First, is endogenous attention more vulnerable to time-on-task than exogenous attention? Second, do measures of autonomic arousal provide evidence to support the underload vs overload hypothesis? And third, do these measures show a different effect for endogenous and exogenous attention? We applied a cued (valid vs invalid) conjunction search task, and ECG and respiration recordings were used to compute sympathetic (normalized low frequency power) and parasympathetic tone (respiratory sinus arrhythmia, RSA). Behavioural results showed a dual effect of time-on-task: the usually described vigilance decrement, expressed as increased reaction times (RTs) after 30 min for both conditions; and a higher cost in RTs after invalid cues for the endogenous condition only, appearing after 60 min. Physiological results clearly support the underload hypothesis to subtend the vigilance decrement, since heart period and RSA increased over time-on-task. There was no physiological difference between the endogenous and exogenous conditions. Subjective experience of participants was more compatible with boredom than with high mental effort.

PMID: 17999934 [PubMed - as supplied by publisher]

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Wednesday, November 14, 2007

News About Ion Channels

A press release from the NIH:

Scientists Zero in on the Cellular Machinery that Enables Neurons to Fire

If you ever had a set of Micronauts — toy robots with removable body parts — you probably had fun swapping their heads, imagining how it would affect their behavior. Scientists supported by the National Institutes of Health have been performing similar experiments on ion channels — pores in our nerve cells — to sort out the channels' key functional parts.

In the November 15 issue of Nature, one group of researchers shows that a part of ion channels called the paddle is uniquely transplantable between different channels. Writing in the same issue, another group exploited this property to probe the three-dimensional structure of ion channels on an atomic scale.

"The effects of many toxins and therapeutic drugs, as well as some diseases, can be wholly explained by changes in ion channel function," says Story Landis, Ph.D., director of the National Institute of Neurological Disorders and Stroke (NINDS), part of the NIH. "We also know that ion channels are at least a contributing player in epilepsy, chronic pain, Parkinson's disease and other disorders. As we learn more about how channels work, we're able to pursue more approaches to treatment."

Ion channels are proteins that control the flow of electrically charged salt particles (ions) across the nerve cell membrane. It's the opening and closing of these channels that enables nerve cells to fire off bursts of electrical activity. A built-in voltmeter, called a voltage sensor, pops the channel open when the nerve cell is ready to fire. The papers in Nature hone in on a part of the voltage sensor called the paddle, named for its shape.

In the first study, a team led by NINDS senior investigator Kenton Swartz, Ph.D., shows that the paddle works as a modular unit. Using recombinant DNA technology, they swapped the paddle from an ion channel found in an ancient, volcano-dwelling bacterium to a channel found in rat brain. As long as the paddle was intact, the hybrid channel still worked. This portability could one day be exploited to test potential drugs. For example, researchers who want to target a paddle from a poorly characterized ion channel could stick it into a well-studied channel where the effects of drugs are easier to measure.

Other results in the paper suggest that the paddle itself will be a useful target for new therapeutic drugs. Dr. Swartz's group found that the paddle is the docking site for certain toxins in tarantula venom, which are known to interfere with ion channel opening. There are hints that scorpions, sea anemones and cone snails make similar toxins, Dr. Swartz said. If nature has found ways to manipulate ion channel function, medicinal chemists might be able to do the same, he said.

In the second study, supported by the National Institute of General Medical Sciences (NIGMS), researchers took advantage of the paddle's unique transplantability to create a hybrid ion channel ideal for structural studies. Led by Roderick MacKinnon, M.D. — a Nobel Laureate, an investigator of the Howard Hughes Medical Institute and a biophysicist at Rockefeller University in New York — the team produced data that explain how the voltage sensor is positioned within the membrane and how it triggers channel opening.

"The determination of the three-dimensional structures of ion channels has yielded a framework to understand their fascinating functional properties," says NIGMS director Jeremy M. Berg, Ph.D. "These new results show how clever experimental designs can focus on key questions and steer the direction of additional studies."

NINDS and NIGMS are components of the National Institutes of Health (NIH). NINDS (www.ninds.nih.gov) is the nation’s primary supporter of biomedical research on the brain and nervous system. NIGMS (http://www.nigms.nih.gov) supports basic biomedical research that is the foundation for advances in disease diagnosis, treatment and prevention.

The National Institutes of Health (NIH) — The Nation's Medical Research Agency — includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. It is the primary federal agency for conducting and supporting basic, clinical and translational medical research, and it investigates the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit www.nih.gov.

References:

Alabi AA, Bahamonde MI, Jung HJ, Kim JI, Swartz KJ. "Portability of Paddle Motif Function and Pharmacology in Voltage Sensors." Nature, November 15, 2007.

Long SB, Tao X, Campbell EB, MacKinnon R. "Atomic Structure of a Kv Channel in a Lipid Membrane-Like Environment." Nature, November 15, 2007.

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Tuesday, November 13, 2007

Brainy Non-Brain Event: Joe Strummer: The Future is Unwritten

Julien Temple's new documentary about Joe Strummer, The Future is Unwritten, opened a couple of weeks ago at the IFC off 4th Street in Manhattan. An excellent movie about an extraordinary musician! Check it out when it comes to your city.

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Neuropsychology Abstract of the Day: Schizophrenia

Barrera A, McKenna PJ, & Berrios GE. Two new scales of formal thought disorder in schizophrenia. Psychiatry Research. 2007 Nov 6; [Epub ahead of print]

Warneford Hospital, Oxford, OX3 7JX, UK.

Information provided by patients and respective carers may help to understand formal thought disorder (FTD) in schizophrenia. Two scales, one for patients (FTD-patient) and one for carers (FTD-carer), were constructed to assess pragmatics, cognitive, paralinguistic, and non-verbal aspects of communication. In the first scale the patients themselves assess their verbal communication; in the second scale the carer assesses the speech of the respective patient. Both scales exhibited internal reliability and evidence of good test-retest reliability. Higher total scores on both scales (FTD-patient and FTD-carer) were significantly associated with positive FTD, but not with negative FTD. Principal component analysis of the scales yielded a multidimensional structure. It is suggested that FTD in schizophrenia may be associated with a range of deficits (e.g. pragmatics, lexical activation, working memory, sustained attention). These scales, in conjunction with the clinician's assessment, can provide a more comprehensive picture of FTD in schizophrenia, revealing its dimensions and making it possible to establish associations between symptoms of FTD and neuropsychological, neurophysiologic, and neuroimaging data. In addition, they provide service users' and carers' perspectives for the assessment of communication in schizophrenia.

PMID: 17997165 [PubMed - as supplied by publisher]

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Brain MRI Tessellation

From the excellent blog, MedGadgets, a post about MRI dynamic computer modelling for neurosurgical interventions: link.

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Monday, November 12, 2007

Swarm Intelligence: Ants and the Collective Mind

Carl Zimmer has a piece in tomorrow's New York Times about swarm intelligence. Read Carl's blog The Loom at this link.


From Ants to People, an Instinct to Swarm
Carl Zimmer
13 November 2007
The New York Times

If you have ever observed ants marching in and out of a nest, you might have been reminded of a highway buzzing with traffic. To Iain D. Couzin, such a comparison is a cruel insult — to the ants.

Americans spend a 3.7 billion hours a year in congested traffic. But you will never see ants stuck in gridlock.

Army ants, which Dr. Couzin has spent much time observing in Panama, are particularly good at moving in swarms. If they have to travel over a depression in the ground, they erect bridges so that they can proceed as quickly as possible.

“They build the bridges with their living bodies,” said Dr. Couzin, a mathematical biologist at Princeton University and the University of Oxford. “They build them up if they’re required, and they dissolve if they’re not being used.”

The reason may be that the ants have had a lot more time to adapt to living in big groups. “We haven’t evolved in the societies we currently live in,” Dr. Couzin said.

[ ... Read the full article ... ]

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Neuropsychology Abstract of the Day: Deep Brain Stimulation (DBS)

This looks like an interesting article that I've added to my list of pubs to read:

Schiff ND & Fins JJ. Deep brain stimulation and cognition: moving from animal to patient. Current Opinions in Neurology. 2007 Dec; 20(6): 638-642.

Department of Neurology and Neuroscience, Weill Medical College of Cornell University, New York, New York, USA.

PURPOSE OF REVIEW: Brain electrical stimulation has been proposed as a strategy to improve chronically impaired cognitive function. This brief review places a small number of recent studies into a broader historical context and identifies important challenges for further development of this area of research. RECENT FINDINGS: Behavioral improvements following severe brain injury with central thalamic deep brain stimulation were observed in experimental studies conducted in rodents and a report on a single human. These findings suggest that this technique warrants further study as a method to modulate cognitive function in the setting of acquired brain injury. SUMMARY: This area of research offers the promise of new avenues to engage patients with nonprogressive brain injuries who, at present, have rather limited therapeutic options. These efforts, however, will require careful attention to issues of research and clinical ethics and study design.

PMID: 17992082 [PubMed - in process]

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Thursday, November 08, 2007

The Game Brain

An excellent op-ed piece in today's New York Times about the value of exercise - of the physical variety - in mental gymnastics. A Risser suggestion to supplement the intent of the opinion writers: get out there and walk around, but take a camera with you - not only do you get the physical exercise, but you challenge yourself cognitively (and may well get some framable results!)

Exercise on the Brain
By SANDRA AAMODT and SAM WANG
Published: November 8, 2007

[snip]

How might exercise help the brain? In people, fitness training slows the age-related shrinkage of the frontal cortex, which is important for executive function. In rodents, exercise increases the number of capillaries in the brain, which should improve blood flow, and therefore the availability of energy, to neurons. Exercise may also help the brain by improving cardiovascular health, preventing heart attacks and strokes that can cause brain damage. Finally, exercise causes the release of growth factors, proteins that increase the number of connections between neurons, and the birth of neurons in the hippocampus, a brain region important for memory. Any of these effects might improve cognitive performance, though it’s not known which ones are most important.

[snip]

[ ... Read the full piece ... ]