How do bodies send sensory signals?


Sensory signals in the body are sent through a specific process that involves sensory neurons, the spinal cord, and the brain. Here's how it typically works:

  1. Sensory Neurons: Nociceptors in the skin and other tissues detect various stimuli such as temperature, pressure, or chemical changes. These receptors transform these physical stimuli into electrical signals [1 ].

  2. Signal Transmission: These electrical signals travel through sensory neurons to the spinal cord. Depending on the type of stimulus, different fibers like A-delta or C fibers carry these signals at varying speeds. A-delta fibers transmit quickly and are responsible for sharp, immediate pain, while C fibers carry slower, dull signals [1 ].

  3. Spinal Cord Processing: Once in the spinal cord, these signals are modulated before being relayed to the brain. This modulation can enhance or diminish the sensory perception [1 ].

  4. Brain Reception: The signals reach the brain where they are integrated and interpreted as specific sensations such as pain. This process involves various brain regions and is subject to influence by factors like emotions and past experiences [1 ].

  5. Motor Response: In cases like reflex actions, the sensory input can lead to an immediate motor response without the need for conscious brain involvement. This is seen in reflex actions where muscles contract in response to sensory input for protective purposes [2 ].

This complex system allows the body to respond to environmental stimuli efficiently, but it's also influenced by higher cognitive functions and emotional states, making the sensory experience highly individualized.

The Science of Pain

Pain is not just a physical sensation, but a complex experience shaped by our brains. In this episode, Sean explains how pain signals are transmitted and processed in the body, debunking the misconception of a direct link between stimulus and pain. He also highlights the challenges of understanding and empathizing with others' experiences of chronic pain.

Huberman Lab

Dr. Sean Mackey: Tools to Reduce & Manage Pain