0, that has an estimated maximum, OR: 1.15 (95% CI: 1.08–1.22)
Physiology
The first study to identify the nociceptive pathway of non-anesthetized cats was performed by Strasser. Cats were anesthetized with sodium pentobarbital and were placed in a stereotaxic frame. The spinal cord was stimulated at the level of the cervical spine, and the brain's second order neurons were studied in a brain stem preparation. This study was followed up by Purpura in 1964 with further study by Spiers in the 1980s.
However, prior to these studies, experiments involving thermoregulation were performed by Peter Strasser. Strasser placed cats in an environmental chamber and stimulated the spinal cord. The chamber was opened to allow the animals to thermoregulate by increasing and decreasing the temperature, and the temperature of the cats' rectal temperature was recorded. The temperature of the spinal cord was increased and decreased with the environment, indicating that thermoregulation was controlled by the spinal cord. These experiments showed that, while the spinal cord has a significant role in thermoregulation, the brain itself, the hypothalamus, plays a significant role in this process.
Nociception is the process of detecting painful stimuli and triggering the appropriate response. Nociceptors and peripheral nervous system nerve endings can be found all throughout the body. Their activation causes the sensory nervous system to send a signal to the brain, which can then be interpreted as a pain signal. Nociceptors have two main properties: excitability and activation.
Excitability is when the nociceptor is active. Nociceptors are excitable, and when noxious stimuli are applied to them, the nociceptor will become more and more excitable until it reaches its maximum threshold. A nociceptor's maximum threshold can be determined by applying a stimulus and recording the response.
Activation is when the nociceptor is active and sends a signal to the spinal cord. The nociceptor sends this signal when it reaches its maximum threshold.
The somatosensory system has two subdivisions, Aβ and Aδ. The Aβ pathway is the faster and more direct pathway, and is not associated with the conscious response. However, the Aδ pathway ac619d1d87
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