Neurotransmission timing key to quick thinking

Researchers from NUS Medicine discovered that the speed and timing of neurotransmission is key to quick thinking.

Quick thinking and speedy reactions are key skills needed in this fast-paced, competitive world. According to new research from the NUS Yong Loo Lin School of Medicine, the speed with which one is able to grasp, process, understand, store and use information boils down to one thing – the timing of the neurotransmission happening in the brain. 

The proposed process occurring in the brain when identifying objects and making quick decisions is known as spike-timing-dependent plasticity (STDP). STDP occurs in the hippocampus — a brain region critical for the formation of memory — and also helps explain a variety of spatial and temporal sequence learning. For example, STDP is employed when identifying the trajectory of a fast approaching ball and avoiding it swiftly.

The STDP model depends on the strength of the connection between the neurons, known as the synapse, which underlies learning and the formation of memory in the brain. In STDP, incoming information triggers an electrical spike in the pre-synaptic neuron, which stimulates the neuron to release neurotransmitters across the synapse to the post-synaptic neuron, where information is converted back into an electrical spike. 

In the study conducted by NUS Medicine, the researchers found that when the pre- and post-synaptic neurons are active at the same time — less than 30 milliseconds apart — the connections between them are strengthened. This means that the information is received, stored and acted upon more rapidly.

The team observed that when the pre- and post-synaptic spikes occur at the same time, the increase in connection can persist for several hours; the connection is even strengthened for weak information such that it gets stored more readily. The effect was also specific to one particular synapse and did not trigger changes in other synapses.  

The study underscores the importance of split-second timing in neuronal activity. It may pave the way for a better understanding of a range of disorders linked to the central nervous system. These could include autism spectrum disorders, schizophrenia and learning disabilities. 

NUS Medicine Associate Professor Sajikumar Sreedharan, who led the study, explained, "In the case of autism spectrum disorders, some neural systems are more active than others. This could be the reason why some autistic people are good at certain tasks like arts or mathematics, but have difficulty socialising,”. 

He continued, “We could possibly leverage artificial intelligence to identify the neural networks that are more or less active, and normalise their functioning using the STDP rules.”

Dr Christopher Chen, Senior Consultant Neurologist at the National University Hospital commented that the findings could also enable clinicians to help patients suffering from memory loss. “This study may provide the foundation for understanding how such timing differences alter brain function, and how these changes could be reversed or mitigated,” he explained. 

See press release.