The human brain is the source of a person’s thoughts, emotions, perceptions, actions, and memories. One challenge for neuroscience is to achieve an integrated understanding of brain-wide interactions, particularly the patterns of neural activities giving rise to functions and behavior. Now, a study from researchers at the University of Hong Kong shows low-frequency activity propagates in the dorsal hippocampal–cortical pathway, to drive interhemispheric cortical resting-state fMRI (rsfMRI) connectivity, and mediate visual processing. The team states their data indicates the hippocampus should be considered as the heart of the brain, a breakthrough in the knowledge of how the brain works. The opensource study is published in the journal (PNAS).
Previous studies show the hippocampus, located underneath the cortex, plays an important role in memory and navigation. Alzheimer’s disease and other forms of dementia have been proven to affect and damage this area, resulting in early symptoms such as short-term memory loss or disorientation. However, the role of the hippocampus in complex brain networks, particularly its influence on brain-wide functional connectivity, is not well understood. The current study shows low-frequency activity propagates in the dorsal hippocampal–cortical pathway, to drive interhemispheric cortical rsfMRI connectivity, and mediate visual processing.
The current study utilizes optogenetics and fMRI to investigate how excitatory neural activity initiated in the dorsal dentate gyrus of the hippocampus propagates and modulates rsfMRI connectivity. Results show low-frequency activities in the hippocampus drive brain-wide functional connectivity in the cerebral cortex and enhance sensory responses. Data findings show low-frequency activities of the hippocampus drive the functional integration between different regions of the cerebral cortex and enhance the responsiveness of vision, hearing, and touch.
Results show low-frequency activities in the hippocampus can enhance learning and memory as these activities usually occur during slow-wave sleep. The lab states it could reasonably be expected for the hippocampus to generate high-frequency activities, however, their data indicates low-frequency optogenetic excitation of the dorsal dentate gyrus evokes cortical and subcortical activities.
The team surmises their study highlights the important role of slow-wave activity in the hippocampal–cortical region in driving brain-wide connectivity and mediating sensory processing. For the future, the researchers state their findings signify the potentials of rsfMRI and neuromodulation for early diagnosis and enhanced treatment of brain diseases including dementia and PTSD.
Source: University of Hong Kong
Get Healthinnovations delivered to your inbox:
Michelle Petersen is the founder of Healthinnovations, having worked in the health and science industry for over 21 years, which includes tenure within the NHS and Oxford University. Healthinnovations is a publication that has reported on, influenced, and researched current and future innovations in health for the past decade.
Michelle has been picked up as an expert writer for Informa publisher’s Clinical Trials community, as well as being listed as a blog source by the world’s leading medical journals, including the acclaimed Nature-Springer journal series.
Healthinnovations is currently indexed by the trusted Altmetric and PlumX metrics systems, respectively, as a blog source for published research globally. Healthinnovations is also featured in the world-renowned BioPortfolio, BioPortfolio.com, the life science, pharmaceutical and healthcare portal.
Most recently the Texas A&M University covered The Top 10 Healthinnovations series on their site with distinguished Professor Stephen Maren calling the inclusion of himself and his team on the list a reflection of “the hard work and dedication of my students and trainees”.
Michelle Petersen’s copy was used in the highly successful marketing campaign for the mega-hit film ‘Jumanji: The Next Level, starring Jack Black, Karen Gilian, Kevin Hart and Dwayne ‘The Rock’ Johnson. Michelle Petersen’s copywriting was part of the film’s coverage by the Republic TV network. Republic TV is the most-watched English language TV channel in India since its inception in 2017.
An avid campaigner in the fight against child sex abuse and trafficking, Michelle is a passionate humanist striving for a better quality of life for all humans by helping to provide traction for new technologies and techniques within healthcare.