Brain cells and pain

Complex Regional Pain Syndrome (CRPS)

A chronic pain condition that usually affects a limb after an injury, characterized by prolonged or excessive pain.

Neuron classification - Morphology

Neurons can be classified based on their shape and the number/length of their processes: Golgi I neurons have long axons, while Golgi II neurons have shorter axons.

Afferent neurons

Neurons that carry sensory information from the body to the central nervous system (CNS).

Interneurons

Neurons that process information within the CNS, facilitating communication between afferent and efferent neurons.

Motor neurons

Neurons that transmit signals from the CNS to effectors such as muscles and glands.

Nociceptors

Specialized sensory receptors that respond to potentially damaging stimuli by sending pain signals to the brain.

Labelled line theory of pain

A theory positing that specific neurons transmit specific sensory information, creating a one-to-one mapping between the activated neuron and the perceived sensation.

First pain vs Second pain

First pain: A-delta fibres transmit sharp, localized pain; Second pain: C-fibres transmit dull, aching, more diffuse pain.

Population coding theory

A theory that explains pain processing in terms of the co-activation of multiple neurons that transmit various sensory inputs.

Gate control theory of pain

A theory that posits non-painful input can close the 'gates' to painful input, thereby reducing the perception of pain.

Central sensitization

Increased sensitivity of the central nervous system to stimulation, often following tissue injury.

Substantia Gelatinosa (SG)

Inhibitory neurons in the spinal cord that play a role in pain modulation through the gate control theory.

WDR neurons (Wide-Dynamic Range)

Neurons that respond to both noxious and non-noxious stimuli, contributing to pain perception through population coding.

Descending nociceptive control

The process by which the brain modulates pain perception via pathways from the brainstem to the spinal cord.

Pain neuromatrix theory

A theory suggesting that pain perception is generated by a neural network integrating sensory, emotional, and cognitive information.

Attention and pain perception

Attention can modulate pain perception, affecting both spatial summation and spinal nociceptive responses.

Complex Regional Pain Syndrome (CRPS)

A chronic pain condition that usually affects a limb, often developing after injury or surgery.

Neuron classification: Morphology

Neurons categorized based on their structure, including the number and length of processes.

Golgi I neurons

Neurons with long axons that project long distances.

Golgi II neurons

Neurons with shorter axons that project locally.

Afferent neurons

Nerve cells that carry sensory information from the body to the central nervous system.

Interneurons

Neurons that process information within the central nervous system.

Motor neurons

Neurons that transmit signals from the central nervous system to effectors like muscles and glands.

Nociceptors

Sensory receptors that respond to potentially harmful stimuli by signaling pain.

Dimensions of pain

Pain can be characterized by sensory, affective, and cognitive dimensions.

Labelled line theory of pain

The theory that specific neurons are designated to transmit specific sensory information.

A-delta fibres

Myelinated fibers that transmit sharp, localized pain sensations quickly.

C-fibres

Unmyelinated fibers responsible for transmitting dull, aching pains.

Population coding theory

Theory stating that pain perception arises from the activation of large groups of unspecialized neurons.

Wide Dynamic Range (WDR) neurons

Neurons that respond to both noxious and non-noxious stimuli and participate in pain encoding.

Lateral inhibition

A process where an activated neuron inhibits neighboring neurons to sharpen spatial localization of pain.

Gate control theory

Theory proposing that non-painful stimuli can inhibit pain transmission.

Peripheral sensitization

Increased sensitivity to pain due to activation of peripheral nerve endings.

Central sensitization

Increased sensitivity to pain due to changes in the spinal cord's processing of pain signals.

Substantia Gelatinosa (SG)

A layer of the spinal cord that plays a significant role in processing pain signals.

Pain neuromatrix theory

The premise that pain is a multidimensional experience generated by a neural network.

Predictive coding theory

The theory that sensory perception is influenced by predictions about incoming sensory information.

Thalamus

A brain structure that relays sensory information to the cerebral cortex.

Anterolateral system

A pain pathway that transmits signals from the spinal cord to the brain.

Opioid receptors

Receptors in the nervous system that mediate the effects of opioids and pain relief.

Descending modulation

Process by which the brain influences spinal processing of pain.

Morphological classification of neurons

Neurons are classified by their structure such as the number of processes.

Neurotransmitters in pain pathways

Chemical messengers (e.g., NMDA, GABA, serotonin) that modulate pain transmission.

Cognitive context of pain

The influence of cognitive processes on the perception and processing of pain.

Emergency response mechanism

Pain signals that trigger reflex actions to protect from injury.

Receptive fields

The specific area where a sensory neuron can respond to stimuli.

Capsaicin

The active component in chili peppers that affects pain receptors.

TRP-V1 receptors

Receptors that contribute to the sensation of pain and heat.

Nociceptive pathway

The neural pathway responsible for transmitting pain signals to the brain.

Spinal cord involvement in pain

The spinal cord processes pain signals before they reach the brain.

Psychological factors in pain perception

Mental and emotional states that can alter how pain is perceived.

Heightened sensitivity

Increased responsiveness to pain stimuli.

Distraction and pain

Shifting attention away from pain can reduce pain perception.

Behavioral responses to pain

Actions taken in reaction to pain stimuli.

Reflex arc

The neural pathway that mediates a reflex action.

Functional anatomy of pain pathways

The structure and organization of the neural pathways involved in pain signaling.

Pain treatment methods

Therapies such as medication, physical therapy, and psychological interventions.

Neuronal plasticity

The ability of the nervous system to change its structure and function in response to experience.

Chronic pain conditions

Prolonged pain that lasts longer than expected based on the usual recovery periods.

Role of the cortex in pain perception

The brain region that processes and interprets pain signals.

Translational pain research

Research focused on applying findings from basic science to clinical pain management.

Neural encoding of pain

The representation of pain intensity and quality in the nervous system.

Neuroimmune interactions

The interplay between the nervous and immune systems in pain states.

Social influences on pain

Effects of social interaction and support on the experience of pain.

Variability in pain perception

Differences in how individuals perceive and respond to pain.

Pain tolerance

The maximum level of pain that a person can endure.

Rehabilitation approaches for pain

Therapies aimed at helping individuals regain function and reduce pain.

Role of sensory neurons

Neurons that receive and process sensory information.

Pain assessment techniques

Methods used to measure and evaluate pain intensity and quality.