Research at the Institute of Molecular Biology and Biotechnology, published today in the international scientific periodical EMBO Journal, reveals an important molecular mechanism that facilitates learning and the formation of memories by the nervous system.

By using the simple nematode worm Caenorhabditis elegans, IMBB researchers Giannis Voglis and Nektarios Tavernarakis, have discovered a new role for a specific class of proteins in mediating learning and memory.

Although learning and memory are fundamental brain functions they remain poorly understood. What molecular mechanisms underlie the capacity of the nervous system to store information and modify future behaviour? How are these mechanisms regulated? With their study, IMBB researchers demonstrate that specific ion channel proteins modulate communication between groups of neurons that control the behaviour of Caenorhabditis elegans animals.

An important component of learned behaviour is the ability to forecast positive or negative outcomes based on specific sensory cues. This predictive capacity is typically manifested by appropriate behavioural patterning. However, the molecular mechanisms underlying such behavioural plasticity are poorly understood. Caenorhabditis elegans displays experience-dependent behavioural responses by associating distinct environmental signals. Voglis and Tavernarakis have found that a specific ion channel protein called ASIC-1 is required for associative learning in Caenorhabditis elegans. This channel localizes at specific neurons which communicate by releasing the neurotransmitter dopamine. ASIC-1 functions in these neurons to amplify normal dopaminergic signalling, necessary for associative learning. In humans, dopaminergic neurons have been implicated in drug addiction. Also, these neurons degenerate in patients with Parkinson's disease.

Given that the basic mechanisms governing neuronal communication in higher organisms, including humans, are remarkably similar to those in the nematode, it is highly likely that similar ion channel proteins are important for learning and memory in these organisms. Several devastating brain pathologies such as Alzheimer's, Huntington's and Parkinson's disease, various amnesias, brain injury and stroke severely impair the capacity for learning and memory. In addition, age-associated dementia is becoming an increasingly relevant burden of human health and society. Elucidation of the basic molecular mechanisms underlying the progressive decline in neuronal function that accompanies ageing and eventually leads to dementia will have an immediate impact on the design of novel interventions that could reduce or delay age-related brain deterioration in humans. The novel findings reported by IMBB investigators are anticipated to stir innovative research approaches in this direction.

For more information please contact:

Dr. Nektarios Tavernarakis, Research Director, (+30-2810-391066; tavernarakis@imbb.forth.gr)
Relevant links:
http://www.imbb.forth.gr/worms
http://www.nature.com/emboj/journal/vaop/ncurrent/index.html