In pain? Brain neurons are making you act differently
BENGALURU: Chronic physical pain can be debilitating, but feelings of stress, fear and hunger can sometimes suppress painful sensations. Neurons in different parts of the brain play a role in orchestrating pain response in animals, Indian Institute of Science (IISc) scientists said in their new report.
Scientists from the Centre for Neuroscience (CNS), IISc, have now found how neurons work together to control chronic pain in mice, allowing them to cope or suppress the pain. This finding will help researchers devise better therapeutic strategies for chronic pain management, said researchers on Wednesday.
The report ‘Converging inputs compete at the lateral parabrachial nuclei to dictate the affective-motivational responses to cold pain’, was also published in PAIN journal in November 2024.
It stated that scientists studied mice with chemotherapy-induced peripheral neuropathy (CIPN) – a common but less understood side-effect of chemotherapy, which leads to cancer patients becoming hypersensitive to external stimuli like cold temperatures.
They found the brain region called the lateral parabrachial nucleus (LPBN) played a key role in driving this phenomenon.
The report noted that when LPBN neurons were activated, mice licked their paws more frequently – an active coping strategy – in response to a painful cold stimulus. The researchers found that these LPBN neurons act as a relay junction of sorts that controls how much pain the mice feel and how they cope with it.
Arnab Barik, CNS Assistant Professor and co-author of the report, said some patients suffering from arthritis or CIPN feel a lot more pain triggered by certain stimuli that healthy individuals generally don’t feel.
Prannay Reddy, co-author, said CIPN mice showed similar signs. “For us to feel pain in a situation where we shouldn’t feel pain, something must go wrong in the brain. There should be more firing or misfiring (of neurons) in certain regions of the brain.”
The team also found that when they activated inhibitory inputs from another brain region -- the lateral hypothalamus which is primarily involved in regulating feelings like stress and hunger – it reduced the cold-induced licking response and presumably the painful sensations.
Barik cited an example: “If you’re very hungry and you have back pain, you can still manage the pain and go over to finding food. Now if you have an intense pain attack, where all these neurons are really stimulated, then you are not going to go looking for food. The brain computes that.”