Representative image of brain
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Bengaluru: Chronic physical pain is debilitating, but sensations like stress, fear, or hunger can sometimes suppress pain.
Scientists at the Centre for Neuroscience (CNS), Indian Institute of Science (IISc), Bengaluru, have uncovered how neurons in different brain regions collaborate to control chronic pain in mice, potentially offering insights for better pain management therapies.
The study, led by Arnab Barik, Assistant Professor at CNS, focused on chemotherapy-induced peripheral neuropathy (CIPN) in mice, a poorly understood side effect of chemotherapy that makes cancer patients hypersensitive to external stimuli, such as cold temperatures. The researchers identified a brain region called the lateral parabrachial nucleus (LPBN) as a critical player in this phenomenon.
Non-addictive pathways
Speaking to DH, Barik explained that this research could pave the way for non-opioid pain treatments. “We typically use drugs to treat pain, but many of them can lead to addiction. Identifying neural pathways to mitigate pain without addiction could significantly improve pain management,” he said.
Key findings
The study revealed that activating LPBN neurons prompted mice to lick their paws more frequently in response to painful cold stimuli — an active coping strategy. These neurons act as a “relay junction”, integrating inputs from different brain regions to regulate pain intensity and coping behaviour.
The researchers found that excitatory inputs from the spinal cord to LPBN neurons heightened pain perception, increasing the paw-licking behaviour.
Inhibitory inputs from the lateral hypothalamus, a brain region associated with stress and hunger regulation, reduced the cold-induced licking response and likely the painful sensations.
Both excitatory and inhibitory signals converge on the same set of LPBN neurons. Depending on the strength and type of inputs, these neurons determine whether the pain response intensifies (more licking) or diminishes (less licking).