Video Experimental Relacionado
Updated: Aug 12, 2026
07:23
Assessment of Morphine-induced Hyperalgesia and Analgesic Tolerance in Mice Using Thermal and Mechanical Nociceptive Modalities
Published on: July 29, 2014
Morfina que reduce los umbrales de autoestimulación: falta de tolerancia con la administración a largo plazo
Science (New York, N.Y.)
|January 14, 1977
Resumen
Las ratas desarrollaron tolerancia a la morfina, pero el fármaco redujo constantemente su umbral de autoestimulación. Esto indica un efecto duradero en el sistema nervioso central de la morfina, potencialmente relacionado con sus propiedades eufóricas.
Área de la Ciencia:
- La neurociencia es la neurociencia.
- Farmacología Farmacología.
- Ciencias del comportamiento Ciencias del comportamiento.
Sus antecedentes:
- La morfina es un analgésico opioide con efectos conocidos en el sistema nervioso central.
- El desarrollo de tolerancia a los opioides es un fenómeno común, que afecta a la eficacia del medicamento.
- Comprender los efectos persistentes de los opioides es crucial para la investigación de la adicción.
Objetivo del estudio:
- Para investigar los efectos a largo plazo del sistema nervioso central de la morfina.
- Para determinar si el impacto de la morfina en el comportamiento de autoestimulación cambia con el desarrollo de la tolerancia.
- Explorar los mecanismos potenciales que subyacen a la euforia inducida por los opioides.
Principales métodos:
- A las ratas se les administraron dosis crecientes de morfina durante varias semanas para inducir la tolerancia.
- Se midió el efecto de la morfina en el umbral para el comportamiento de autoestimulación.
- Se analizaron las respuestas conductuales para evaluar los cambios en la sensibilidad a los medicamentos.
Principales resultados:
- La administración a largo plazo de morfina condujo a la tolerancia en las ratas.
- A pesar de la tolerancia, la morfina continuó disminuyendo el umbral de autoestimulación.
- El efecto de la droga en este comportamiento específico se mantuvo constante a lo largo del estudio.
Conclusiones:
- La morfina ejerce un efecto central persistente que no se elimina con la tolerancia.
- Este efecto sostenido sobre la autoestimulación puede estar asociado con los aspectos gratificantes o eufóricos de la morfina.
- Se necesita más investigación para dilucidar los fundamentos neurobiológicos de esta acción persistente.
Videos de Conceptos Relacionados
01:20Desensitization and Tachyphylaxis
Tachyphylaxis is described as a rapid decrease in response to a drug after repeated or continuous administration of the same drug dose. It is a phenomenon where the body becomes less responsive to a particular substance or intervention over time, requiring higher doses or stronger interventions to achieve the same effect. It results from adaptive changes in the body's receptors, signaling pathways, or physiological processes that occur in response to prolonged exposure to a stimulus.
Several...
Several...
01:15Drug Abuse and Addiction: Pharmacological Phenomena
Drug dependence, abuse, and addiction are complex phenomena that can precipitate various abnormal states. Physical dependence refers to a state of pharmacological adaptation to a drug. This adaptation often results in tolerance—a reduced response to the drug after repeated administrations. When the drug use is abruptly stopped, withdrawal symptoms occur due to the body's need to readjust from the pharmacologically induced imbalance. However, tolerance and withdrawal symptoms do not necessarily...
01:22Opioid Receptors: Overview
Opioid receptors, including the mu (μ, MOR), delta (δ, DOR), and kappa (κ, KOR) types, belong to the rhodopsin family of G protein-coupled receptors. These receptors are located throughout the central and peripheral nervous systems and in non-neuronal tissues such as macrophages and astrocytes. Opioid receptor ligands can be categorized into agonists or antagonists. Highly selective agonists include [d-Ala2, MePhe4, Gly(ol)5]-enkephalin or DAMGO for MOR, [D-Pen2, D-Pen5]-enkephalin or DPDPE for...
01:25Analgesia and Pain Management
Pain is critical to various clinical pathologies, provoking an urgent need for effective management. Pain, whether acute or chronic, is a complex neurochemical process. Its alleviation depends on the type, with nonopioid analgesics effective for mild to moderate pain, such as musculoskeletal or inflammatory pain, while neuropathic pain responds best to anticonvulsants, tricyclic antidepressants, or serotonin/norepinephrine reuptake inhibitors. For severe acute or chronic pain, opioids may be...
01:20Opioid Analgesics: Morphine and Other Natural Cogeners
Opioids are a class of drugs that mimic endogenous opioid peptides and act on opioid receptors, and help in pain relief. These compounds are classified as natural, synthetic, or semi-synthetic. Natural opioids, like morphine, codeine, and thebaine, are derived from the opium poppy plant (Papaver somniferum or Papaver album) and are termed opiates. Synthetic opioids are artificial, while semi-synthetic opioids combine natural and synthetic compounds. Morphine, a prototypical opioid, possesses a...
01:15Opioid Analgesics: Synthetic and Semisynthetic Opioids
Synthetic and semisynthetic opioids are pivotal in pain management and tackling opioid addiction. Semisynthetic opioids, including morphinans (morphine derivatives), oxycodone, oxymorphone, hydrocodone, and hydromorphone, have improved pharmacokinetic profiles compared to morphine. Additionally, heroin and 6-MAM (6-Monoacetylmorphine) show better CNS penetration than morphine due to heightened lipid solubility. Hydromorphone, a potent opioid, undergoes hepatic metabolism to form the active...