Memorizing and predicting aversive or unpleasant events is a critical function of neural circuits responsible for survival and emotional well-being. There is much interest in how the brain creates the signals associated with negative emotions in order to better understand how imbalances can lead to affective disorders such as depression and anxiety. However, it is unclear which areas of the brain control feelings of discomfort and aversion. Now, a study from researchers at Karolinska Institutet maps pathways in the mouse brain associated with aversion. The team states it is hoped by understanding the structure and function of this fear and aversion circuitry, it will be possible to design intervention strategies for pathological fear conditions. The opensource study is published in the journal Molecular Psychiatry.
Previous studies have indicated a brain structure called the habenula controls positive and negative emotions in animal models. Moreover, clinical cases have been conducted with patients suffering from depression where deep brain stimulation of the habenula has been beneficial. The habenula controls both dopamine and the neurotransmitter serotonin, which is thought to play a significant part in the sense of wellbeing, however, it is unclear how the habenula is regulated. The current study identifies which networks in the mouse brain control the habenula, and what role they play in aversion.
The current study uses optogenetics, a method using light to activate specific neurons in order to study how the activation of different networks affects behavior, to identify the nerve cells involved in aversion and map their interconnections. Results show lateral habenula (LHb)-projecting lateral hypothalamic area (LHA) neurons are responsible for encoding negative value. Data findings show activation of LHA glutamatergic neurons produces strong aversive responses, and shape the value of actions.
The group states further recordings using imaging calcium dynamics showed LHA glutamatergic neurons formed activity clusters representing distinct reward or aversion signals, including a population responding to mild foot shocks and predicted aversive events. They also observed the LHb-projecting LHA glutamatergic neurons encode negative valence and rapidly develop a prediction signal for negative events or aversion.
The team surmises they have identified a specific pathway running between the hypothalamus and the habenula, which can be modulated using optogenetics to control the feeling of aversion. For the future, the researchers state their data could lead to the development of new treatments which can rebalance the brain’s networks in disorders such as depression or anxiety.
Source: Karolinska Institutet
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.