MUPLUS+   Join Plus+ and get exclusive shows and extensions! Subscribe Today! LEARN MORE  

 
Close

Advertise here now!

 
 

“GABA, GABA!” The Smoking Gun of Alzheimer’s?

Probing the depths of the human mind is no easy task. An image of deep thinking philosophers, physicians, or in a pinch, a scene from Fantastic Voyage, comes to mind. Neurology or philosophy; nuts and bolts or the spiritual house of the soul. Yet a question that continues to perplex everyone is, why does our mental powers decay with years?

pythagoras

The Greeks and the Romans saw it as a natural side effect of aging. “The return to infancy” as Pythagoras puts it. While the Roman philosopher Cicero insisted that “it is our duty to resist old age; to fight against it as we would fight against disease”. What never occurred to them is that part of it was a disease!

Mental decay being linked to anything other than age did not come into the scientific consciousness until the early twentieth century, when German doctor Alois Alzheimer first noticed large amounts of a plaque like substance interwoven throughout the brains of deceased patients who had died of rapid onset dementia. This led scientists at the time to come to the conclusion that they were dealing with an actual disease, rather than just the natural progression of life.

Alzheimer’s disease, as it became known, is associated with build-ups in the brain of two different types of proteins: amyloid beta, and amyloid tau. Beta proteins bind together to form a plaque like substance outside of neurons. Whereas, the tau proteins link together into fibrils inside of the nerve cells of the brain. However different, the result is the same. Brain cells become injured and die, leading to rapid deterioration of memory, cognition and behavior.

Over the past hundred years, researchers have worked tirelessly to find a cure, and the results were…not all that promising. Hundreds of drugs and thousands of clinical studies have been undertaken across the globe with the hope of finding a cure. Most of these studies focus on combating the aggressive advancement of Tau and Beta deposits. But sadly, the drugs to date have had little or in some cases the reverse effect.

However, a recent study published in Nature Communications could offer new hope. Researchers from Pennsylvania State University have located a new target in the fight against Alzheimer’s. Unlike previous attempts, research headed by Gong Chen, a Professor of Biology for Penn State, focused on discovering different source for the disease than those identified by Alois Alzheimer more than a century before.

“Billions of dollars were invested in years of research leading up to the clinical trials of those Alzheimer’s drugs, but they failed the test after they unexpectedly worsened the patients’ symptoms,” Chen said.

Chen and his team succeeded, and have unveiled the new smoking gun of Alzheimer’s, GABA!

Chen_astrocytes_6-2014

Photo credit: Gong Chen Labs, Penn State University

GABA (gamma-aminobutyric acid) is a neurotransmitter, which was recently observed to be abnormally high in affected patients. Specifically, in the dentate gyrus, a section of the brain that serves as a gateway to the hippocampus, which houses the centers learning and memory.

Could this be the source of Alzheimer’s?

Through a series of studies conducted using mice, Chen and his team discovered a transporter of GABA that is predestined for the dentate gyrus, the local of the abnormally high concentrations of the neurotransmitter. This transporter can serve as a big red target for future clinical research.

By targeting the transporters of GABA within the brain, Chen proposes that it may be possible to reverse the deterioration of the brain. “After we inhibited the astrocytic GABA transporter to reduce GABA inhibition in the brains of the AD mice, we found that they showed better memory capability than the control AD mice.” Says Chen.

Further research is currently underway, with hopes of a successful human therapy close behind.

 TAGS: , , , ,

  • Lane Simonian

    Peroxynitrite is a potent oxidant that is likely the cause of Alzheimer’s disease. It contributes to the formation of the amyloid precursor protein, the aggregation of amyloid plaques, the hyperphosphorylation and nitration of tau proteins (which may disrupt neurotransmissions), reduces the flow of blood in the brain, contributes to tissue damage and inflammation, limits the release and synthesis of neurotransmitters involved in short-term memory, social recognition, sleep, mood, and alertness, prevents the regeneration of neurons, and contributes to the death of neurons. It also causes an increased release of GABA.

    Abstract

    Role of peroxynitrite in [3H] gamma-aminobutyric acid (GABA) release evoked by N-methyl-D-aspartate (NMDA) and S-nitroso-N-acetyl-penicillamine (SNAP) and mechanisms of [3H]GABA release induced by peroxynitrite in comparison with those induced by NMDA and SNAP were investigated using cerebrocortical neurons. NMDA dose dependently increased [3H]GABA release, which was significantly inhibited by hemoglobin and superoxide scavengers, Cu2+, Zn(2+)-superoxide dismutase and ceruloplasmin. The NMDA-evoked [3H]GABA release was significantly suppressed by GABA transport inhibitors and inhibitors of voltage-dependent L-typed Ca2+ channel. The SNAP-evoked [3H]GABA release was significantly reduced by Ca2+ withdrawal and by GABA transport inhibitors either in the presence or absence of Ca2+. Similar patterns of [3H]GABA release induced by peroxynitrite were observed. These results indicate that peroxynitrite formed by the reaction of NO with superoxide participates, in part, in the release of [3H]GABA induced by NMDA and SNAP.

    Clinical trials using peroxynitrite scavengers such as eugenol in rosemary essential oil via aromatherapy (Jimbo, et al.), eugenol in a carefully prepared tincture of lemon balm essential oil (Akhondzadeh, et al.), and ferulic acid, syringic acid, and vanillic acid (Heo, et al.) have partially reversed Alzheimer’s disease in small-scale human clinical trials.