Name: pain signaling and inflammation
Uploaded: 2025-10-23T11:49:14.000Z
Duration: 1 min 44 s
Channel: JoVE

- [Istruttore] La nocicezione,
chiamata di solito dolore,

è il processo attraverso
cui uno stimolo nocivo

viene trasmesso attraverso
il sistema nervoso periferico

e centrale

per avvertire di un danno
o un infortunio potenziale.

Quando un segnale dannoso viene percepito,

i nocicettori, terminazioni
nervose libere, si attivano.

I mastociti vicini
rilasciano sostanze chimiche

come le istamine mentre i
macrofagi secernono citochine,

piccole proteine che
sono fattori essenziali

nella segnalazione immunitaria.

Contemporaneamente, gli
assioni dei nocicettori

trasmettono il segnale al corno
dorsale del midollo spinale

attraverso due diverse fibre del dolore.

Le prime ad essere attivate sono

le fibre A-delta sottilmente mielinizzate

che conducono dolore immediato
intenso e ben localizzato

molto velocemente, per permettere al corpo

di allontanarsi dallo stimolo doloroso.

L'altro tipo di assioni sono le fibre C,

che conducono lentamente
poiché non mielinizzate

e trasmettono un dolore
prolungato con bruciore.

Dal midollo spinale, i
segnali del dolore passano

e viaggiano al tronco encefalico,

seguito dal talamo e dalla
corteccia somatosensoriale

dove i segnali del
dolore sono interpretati

per determinare la
posizione dell'infortunio.

Altre regioni del cervello
elaborano il dolore,

specialmente le strutture
cortico-limbiche,

compresa l'amigdala e
la corteccia prefrontale

che sono legate alle memorie
emotive e alla cognizione.

Infine, le varie interazioni
all'interno del cervello

contribuiscono alla percezione soggettiva

che gli individui provano.

San Giovanni Smith, Ewan. "Progressi nella comprensione della nocicezione e del dolore neuropatico". Giornale di neurologia 265, n. 2 (2018): 231–38. [<a href="https://doi.org/10.1007/s00415-017-8641-6" target="__blank">Sorgente</a>]

Pinho-Ribeiro, Felipe A., Waldiceu A. Verri e Isaac M. Chiu. "Interazioni neurone-immunitarie sensoriali nocicettore nel dolore e nell'infiammazione". Trends in Immunology 38, n. 1 (gennaio 2017): 5–19. [<a href="https://doi.org/10.1016/j.it.2016.10.001" target="__blank">Sorgente</a>]

nocicezione

Nociception

La nocezione, la capacità di provare dolore, è essenziale per la sopravvivenza e il benessere generale di un organismo. Stimoli nocivi come il dolore penetrante da un oggetto acuto, il calore da una fiamma aperta o il contatto con sostanze chimiche corrosive vengono rilevati per la prima volta dai recettori sensoriali, chiamati nocicettori, situati sulle terminazioni nervose. I nocicettori esprimono canali ionici che convertono stimoli nocivi in segnali elettrici. Quando questi segnali raggiungono il cervello tramite neuroni sensoriali, sono percepiti come dolore. Così, il dolore aiuta l'organismo a evitare stimoli nocivi.

Il sistema immunitario svolge un ruolo essenziale nella patologia del dolore. Dopo aver incontrato stimoli nocivi, cellule immunitarie come mastociti e macrofagi presenti sul sito di lesioni rilasciano sostanze chimiche infiammatorie come citochine, chemiochine, istamine e prostaglandine. Queste sostanze chimiche attirano altre cellule immunitarie come monociti e cellule T al sito di lesione. Stimolano anche i nocicettori, con conseguente iperalgesia, una risposta più intensa a uno stimolo precedentemente doloroso, o allodinia, una risposta dolorosa a uno stimolo normalmente innocuo come il tocco leggero. Tale sensibilizzazione al dolore aiuta a proteggere il sito ferito durante la guarigione.

In alcuni casi, il dolore supera il suo ruolo di sistema di allarme acuto se la sensibilizzazione non riesce a risolversi nel tempo. Il dolore cronico , dolore persistente o ricorrente che dura più di tre mesi, spesso accompagna condizioni infiammatorie come l'artrite reumatoide. Farmaci antinfiammatori non steroidei (NSAID) come l'aspirina e l'ibuprofene riducono il dolore inibendo la sintesi delle molecole infiammatorie prostaglandine. Tuttavia, FANS e oppioidi attualmente utilizzati per combattere il dolore soffrono di gravi effetti collaterali e il potenziale di dipendenza. Pertanto, comprendere i meccanismi alla base della patologia del dolore può aiutare a sviluppare farmaci più efficaci per sopprimere la percezione del dolore con effetti collaterali negativi meno gravi.

Nocicezione

La nocicezione, la capacità di provare dolore, è essenziale per la sopravvivenza e il benessere generale di un organismo. Stimoli nocivi come il piercing ...

Education

Didattica

JoVE Core

Biology

Biologia

Human Biology

Biologia umana

Musculoskeletal System

Sistema muscoloscheletrico

KEY TERMS AND CONCEPTS

TERMINI E CONCETTI CHIAVE

pain signaling and inflammation

Pain signaling begins when the body detects a harmful stimulus. Sharp objects, open flames, and corrosive chemicals can trigger this response. Sensory receptors called nociceptors, which sit on nerve endings, detect these noxious stimuli and use ion channels to turn them into electrical signals.

Those electrical signals travel through sensory neurons to the brain, where they are experienced as pain. This warning system helps an organism avoid damage and stay safe. Pain is therefore an important part of survival and overall well-being.

The immune system also shapes pain after an injury. Mast cells and macrophages at the injury site release inflammatory chemicals such as cytokines, chemokines, histamines, and prostaglandins. These signals attract more immune cells, including monocytes and T cells, and they also stimulate nociceptors.

This immune response can increase pain sensitivity. Hyperalgesia is a stronger response to a stimulus that was already painful. Allodynia is pain caused by something that is usually not painful, such as light touch. These changes help protect the injured area during healing.

Pain can become a problem when sensitization does not fade. Chronic pain is persistent or recurring pain that lasts longer than three months. It often occurs with inflammatory diseases such as rheumatoid arthritis. NSAIDs, including aspirin and ibuprofen, reduce pain by blocking the production of prostaglandins. However, NSAIDs and opioids can cause serious side effects and may lead to addiction, so researchers continue to study pain mechanisms to find safer drugs.

Pain Signaling and Inflammation

what is the skeletal system?

Human Skeleton: Bones, Cells, and Disease

The human skeleton is a living framework made of 206 bones in adults. Bones connect with cartilage, tendons, and ligaments. This system gives the body support, protects organs, and helps with movement and locomotion. The skeleton has two main parts: the axial skeleton and the appendicular skeleton. The axial skeleton has 80 bones and includes the skull, the vertebral column, and the rib cage. The cranium, or upper skull, has eight bones that enclose the brain, while the lower part of the skull...

bone structure

Inside a Long Bone

Inside a long bone, osseous tissue is organized into two main types: cortical bone and cancellous bone. A femur is a clear example of this structure. The bone also includes outer coverings and inner spaces that support growth, repair, and blood cell production. Cortical bone, also called compact bone, forms the dense outer layer along the diaphysis, or shaft. It is covered by the periosteum, a membrane with connective tissue, capillaries, and nerves. Beneath the cortical layer is the medullary...

joints

Types of Joints in the Human Body

Joints are the places where adjacent bones connect. They are also called articulations or articular surfaces. Joints help the body move and stay stable. Joints can be classified by structure or by function. Structural classification depends on the material that forms the joint and whether there is a space between the bones. By structure, joints are fibrous, cartilaginous, or synovial. Fibrous joints are connected by fibrous tissue and have no cavity between the bones. Because of this, they do...

bone remodeling

How Hormones Control Bone Turnover

Bone turnover is a continuous process in which old bone is broken down and new bone is built. Osteoclasts carry out bone resorption, and osteoblasts carry out bone formation. In adults, this balanced cycle helps maintain bone mass and calcium homeostasis. Mechanical stress can also stimulate turnover as part of normal maintenance and repair. Parathyroid hormone, or PTH, helps control blood calcium levels by increasing bone resorption when calcium is low. It is released from the parathyroid...

skeletal muscle anatomy

Muscle Fibers, Tendons, and Contraction

Skeletal muscle moves the body by pulling on bones through tendons. Tendons are the connective tissue that attaches skeletal muscle to bones. When skeletal muscles contract, they create voluntary movement. Skeletal muscle is wrapped in layers of connective tissue. The outer layer is the epimysium, which helps protect the muscle. Beneath it, the perimysium surrounds and groups fasciculi, which are bundles of skeletal muscle cells called myocytes. These cells are also called skeletal muscle...

classification of skeletal muscle fibers

Skeletal Muscle Fiber Speed and Energy

Skeletal muscle fibers can be grouped by how fast they contract and how they make ATP, the energy cells use for movement. These differences also shape their physical features. Most human muscles contain all three fiber types, but in different amounts. Slow oxidative fibers, also called slow-twitch fibers, appear red because they have many capillaries and high levels of myoglobin, an oxygen-storing protein. They also contain more mitochondria, which make ATP through oxidative phosphorylation,...

muscle contraction

Nerve Signals That Trigger Muscle Contraction

Nerve signals trigger muscle contraction in both skeletal and smooth muscle, but the two muscle types use different control systems. In skeletal muscle, the signal begins at the motor end plate, which is the synapse between a motor neuron and a muscle fiber. In smooth muscle, contraction is controlled by the autonomic nervous system and happens without conscious control. In skeletal muscle, motor nerve terminals release acetylcholine. This neurotransmitter binds to receptors on the sarcolemma,...

cross-bridge cycle

Calcium Control in Muscle Contraction

Calcium control in muscle contraction depends on ATP, motor neurons, and the sliding action of actin and myosin. As a muscle contracts, the thin and thick filaments overlap more, and the sarcomere, which is the contractile unit of the muscle, becomes shorter. This process uses energy from ATP and happens in a repeating cycle at the molecular level. Myosin drives the movement of actin through a cross-bridge cycle. When ATP attached to the myosin head is hydrolyzed to ADP, myosin shifts into a...

motor units

How Motor Units Control Muscle Movement

Motor units control skeletal muscle movement. A motor unit includes one efferent motor neuron, which carries signals away from the central nervous system, and all of the muscle fibers it innervates. A single motor neuron can connect with multiple muscle fibers, but each muscle fiber is innervated by only one motor neuron. Lower motor neurons are the efferent neurons that control skeletal muscle, the most abundant type of muscle in the body. Their cell bodies are found in the spinal cord or...

the spinal cord

Spinal Cord Structure and Dermatomes

The spinal cord is the main nerve pathway of the central nervous system. It carries sensory signals from the body to the brain and motor signals from the brain to the body. It begins at the foramen magnum, the opening at the base of the skull, and extends to the level of the first or second lumbar vertebra. In cross-section, the spinal cord is cylindrical and contains both gray matter and white matter. The central canal lies in the middle and is a remnant of the lumen of the primitive neural...

nociception

Pain signaling begins when the body detects a harmful stimulus. Sharp objects, open flames, and corrosive chemicals can trigger this response. Sensory receptors called nociceptors, which sit on nerve endings, detect these noxious stimuli and use ion channels to turn them into electrical signals. Those electrical signals travel through sensory neurons to the brain, where they are experienced as pain. This warning system helps an organism avoid damage and stay safe. Pain is therefore an...

key terms and concepts

Learn how nociceptors detect harmful stimuli, how inflammation boosts pain sensitivity, and why chronic pain can persist after injury.

Pain Signaling and Inflammation | JoVE K12

JoVE Core series brings biology to life through over 300 concise and easy-to-understand animated video lessons that explain key concepts in biology, plus more than 150 scientist-in-action videos that show actual research experiments conducted in today’s laboratories.

biology

JoVE Core Biologia illustra i concetti chiave della biologia grazie a oltre 300 video-lezioni animate, concise e di facile comprensione. Inoltre, negli oltre 150 video di "scienziati in azione", i concetti scientifici vengono applicati e dimostrati da ricercatori attraverso esperimenti in laboratorio.

myJoVE Corporation

Pain Signaling and Inflammation

Description

Transcript

Tags