Trinity College Hosts International Conference on the role of Nervous System and Immune System interactions in Health and Disease

Posted on: 10 June 2010

The PsychoNeuroImmunology Research Society (PNIRS), ‘PsychoNeuroImmunology: Crossing disciplines to combat disease’, was held in Trinity College Dublin, June 2nd-5th  last.  The conference brought together over 300 scientists and clinicians interested in behavioural and neuroendocrine interactions with the immune system and immune-related disease. TCD’s Dr. Thomas Connor of the School of Medicine commented that “Being given the opportunity to host this conference is a testament to the international reputation of Trinity College Institute of Neuroscience in the area of neuroimmunology, where a number of investigators are conducting research focused on the role of the immune and inflammatory processes in neurodegenerative and psychiatric disorders such Alzheimer’s disease, Multiple Sclerosis and Depression”.

Research presented at the conference included:

  • Brains of older individuals may be more susceptible to cognitive deficits during infection
  • Hormone oxytocin helps happy marriages promote faster wound healing
  • A strong sense of purpose in life is linked to lower levels of inflammation

Inflammatory responses to common infections can cause acute cognitive disorders in older individuals, according to research presented at the conference.  “We know that urinary tract infections and surgery are sometimes associated with acute cognitive disorders, in older adults,” said scientist Rodney Johnson from the University of Illinois, USA.  “Our results show that experimental infection leads to an exaggerated inflammatory response in the brain and cognitive deficits that are not seen in similarly treated younger adults,” he said.  The research was funded by the US National Institutes of Health.

“Infection stimulates the release of immune messenger chemicals known as cytokines, which induce the feelings that we normally associated with being ill, such as feeling tired, losing our appetite and having depressed mood”, said Dr Johnson.  “In older adults, cells in the brain called microglia, which produce these cytokines, seem to become hyper-responsive to infection.  This means that when an infection is present, the microglia mount an exaggerated cytokine response, which can lead to the cognitive deficits that we observe”, he said.

These findings may have wider implications, because infection is also a risk factor for delirium in patients with Alzheimer’s Disease and other dementias.  Dr Colm Cunningham, a researcher from Trinity College Dublin, also presented new findings. “Our research is beginning to unravel the mechanisms of delirium.  This occurs when older adults, and those with dementia, experience profound cognitive and emotional disturbances in response to routine infections, which would cause very limited disruption in young healthy individuals”, he said.  “With the support of the Wellcome Trust, I have designed new models of delirium during dementia, which allow us to investigate this very common problem”, said Dr Cunningham.  “Delirium can be an extremely disturbing acute episode, but it also has negative consequences for progression of diseases such as Alzheimer’s disease.  Understanding the mechanistic routes to delirium offers treatment possibilities for both delirium itself and for dementia.”

Both researchers are keen to emphasise that, although their findings are very interesting, these studies were pre-clinical studies and need to be confirmed in large-scale clinical trials before the implications of their findings can be fully understood.

Hormone oxytocin helps happy marriages promote faster wound healing

Married couples who display more positive social interactions heal physical wounds more quickly than less positive couples, according to research presented at the conference. A hormone called oxytocin, which is associated with social bonding, seems to be crucial; individuals with the highest levels of oxytocin showed the fastest wound healing.

Social relationships can have many beneficial effects on health.  This research, funded by the US National Institutes of Health, shows that the hormone oxytocin may be an important link between the quality of our relationships and state of our health.

“We created small blister wounds on the forearms on 37 married couples, and then assessed the rate of healing for two weeks”, explained the lead researcher, Jean-Philippe Gouin from Ohio State University, USA.  “Each couple was also asked to take part in a structured interaction task in which each participant solicited and offered social support to their partner.  During these tasks, we systematically evaluated the quality of the interaction between the couples, and measured the hormone oxytocin in blood samples”, he said.

“Participants who displayed more positive behaviors in our laboratory setting showed faster wound healing than their less positive counterparts,” said Dr Gouin. “Furthermore, individuals with the highest oxytocin levels healed blister wounds faster than the others.  These data suggest that the high oxytocin levels associated with frequent positive communication behavior may be responsible for the impact of positive marital interaction on wound healing”, he added.

A strong sense of purpose in life is linked to lower levels of inflammation

A strong sense of purpose in life may reduce inflammation associated with chronic disease in older adults, according to research presented.  “Older adults often suffer from multiple chronic disease conditions, and inflammation is implicated in the onset and progress of these age-related chronic diseases”, said lead researcher Elliot Friedman from the University of Wisconsin-Madison, USA.  “As the number of chronic conditions increases, the levels of inflammation also increase.  Our new study shows that, in people with similar levels of chronic disease burden, having a strong sense of purpose in life is linked to lower levels of inflammation”, he added.

“This work, funded by the National Institute of Aging, joins a growing scientific literature showing links between positive psychological functioning and better profiles of health. In this case, age is often associated with greater burden of disease, and more disease is typically associated with higher levels of inflammation which themselves predict worse health down the line. This work shows that high levels of inflammation are not an inevitable product of chronic disease – the relationship between chronic disease burden and inflammation is weaker in people with a greater sense of purpose in their lives. We know that negative psychological experiences – depression, stress – contribute to poorer health. We believe that it’s also important to consider the ways in which positive psychological functioning may contribute to better health”, said Dr Friedman.