Senior Research Fellowship
Hong Kong Polytechnic University
Professor HE Jufang is a Professor of Department of Biomedical Sciences at City University of Hong Kong. He is one of the leading neuroscientists in the hearing research and thalamocortical system, and learning and memory studies. He has received training in both engineering and medical sciences.
Professor He Jufang and his team have recently identified the
neuromodulator which plays a crucial role in memory formation. The
neuromodulator is called cholecystokinin (CCK), which enables memory writing in
the neocortex with very high efficiency. The findings may help develop drugs
that can alleviate or even reverse the memory loss process caused by ageing or
forms of dementia such as Alzheimer’s disease.
The research report entitled “Cholecystokinin from the entorhinal cortex enables
neural plasticity in the auditory cortex” was published recently in Cell
Research, a prestigious international journal in life sciences covering all
areas of molecular and cell biology published by the Nature Publishing
“Patients with damage to the medial temporal lobe have great difficulty in
forming new declarative memories but can still recall older memories, suggesting
that the medial temporal lobe is necessary for encoding memories in the
neocortex,” said Professor He.
Professor He and his team therefore investigated the chemical composition
of dozens of neurotransmitters and neuromodulators in the medial temporal lobe
and found that most of the neurons in the region projecting to the neocortex
“According to published research reports, blocking CCK receptors suppresses
conditioned fear and knocking out the CCK receptor gene reduces anxiety-like
behaviour in rodents, suggesting that CCK is associated with memory function. We
conclude that the hippocampal system exerts its influence on cortical
neuroplasticity through the action of CCK. CCK switches on the memory writing in
the neocortex,” explained Professor He.
The researchers in Prof He's lab conducted a series of experiments on rats by
injecting CCK into the rats’ brains and studied the responses.
“A local infusion of CCK in the auditory cortex of an anesthetised rat
allowed its neurons to begin responding to a particular auditory stimulus to
which it previously had shown no response. The CCK infusion also enabled
auditory neurons to start responding to a light stimulus that was paired with a
noise burst,” added Professor He.
The application of a CCK receptor antagonist in the
auditory cortex of rats prevented the formation of memory, according to Prof He.
“The local infusion of a CCK antagonist into the auditory cortex of rats
prevented the formation of a visuoauditory memory in the auditory cortex even
after 180 conditioning trials, in contrast to the successful formation of the
memory after only 20 to 30 trials without the CCK antagonist,” he said.
Using intracellular recording, the researchers found out how memory is
encoded and how visual and auditory stimulations are associated.
He is now directing a collaborative team between CityU and the Drug Discovery
Pipeline at the Guangzhou Institute of Biomedicine and Health, Chinese Academy
of Sciences, for the development of CCK agonists and antagonists.
The first application of the agonist drug is directed at the people who experience
memory deficits, such as people with Alzheimer’s disease.
The application of CCK antagonists includes post-traumatic stress syndrome.
Leaning and Memory