Biomaterial Database

Responses of neurons in the lateral cervical nucleus of the cat to noxious cutaneous stimulation. 1987

K C Kajander, and G J Giesler

The majority of neurons at the origin of the spinocervical tract are driven by noxious stimulation of their receptive fields. Surprisingly, previous studies have encountered only a small percentage of nociceptive neurons within the terminus of the spinocervical tract, the lateral cervical nucleus (LCN). To determine if previous reports have underestimated the proportion of nociceptive LCN neurons, 129 neurons within the nucleus were physiologically identified and examined in cats prepared using three different methods. Fifty-nine percent of the neurons studied in unanesthetized cats that were decerebrated and spinalized responded either differentially or exclusively to noxious mechanical stimulation of the skin within discrete receptive fields. LCN neurons also gave accelerating responses to increasingly more intense noxious thermal stimuli. LCN neurons are, therefore, capable of coding both the intensity and location of noxious stimuli. Only 6% of LCN neurons responded to noxious cutaneous stimuli in unanesthetized, decerebrated cats in which the spinal cord was intact. Only 4% of LCN neurons in intact urethan-anesthetized cats were driven by noxious stimulation. Several previous studies of the LCN have been performed in cats that were deeply anesthetized with barbiturates. Therefore, the effects of barbiturates on the nociceptive responses of LCN neurons were determined. Subanesthetic doses of intravenously administered barbiturates reduced or eliminated the responses of nociceptive LCN neurons to noxious thermal stimuli in decerebrated and spinalized cats. Responses to innocuous mechanical stimuli by these neurons were not blocked by barbiturates. Nociceptive LCN neurons in decerebrated and spinalized cats were somatotopically organized. Neurons with forelimb receptive fields were located in the ventromedial half of the LCN; neurons with hindlimb receptive fields were located in the dorsolateral half of the nucleus. This report and previous studies of the spinocervical tract suggest that the spinocervicothalamic pathway is capable of playing an important role in nociception.

UI	MeSH Term	Description	Entries
D008723	Methohexital	An intravenous anesthetic with a short duration of action that may be used for induction of anesthesia.	Methohexitone,Brevimytal Natrium,Brevital,Brietal,Brietal-Sodium,Methohexital Sodium,Methohexital, Monosodium Salt,Brietal Sodium,Monosodium Salt Methohexital,Natrium, Brevimytal,Sodium, Methohexital
D009619	Nociceptors	Peripheral AFFERENT NEURONS which are sensitive to injuries or pain, usually caused by extreme thermal exposures, mechanical forces, or other noxious stimuli. Their cell bodies reside in the DORSAL ROOT GANGLIA. Their peripheral terminals (NERVE ENDINGS) innervate target tissues and transduce noxious stimuli via axons to the CENTRAL NERVOUS SYSTEM.	Pain Receptors,Receptors, Pain,Nociceptive Neurons,Neuron, Nociceptive,Neurons, Nociceptive,Nociceptive Neuron,Nociceptor,Pain Receptor
D010146	Pain	An unpleasant sensation induced by noxious stimuli which are detected by NERVE ENDINGS of NOCICEPTIVE NEURONS.	Suffering, Physical,Ache,Pain, Burning,Pain, Crushing,Pain, Migratory,Pain, Radiating,Pain, Splitting,Aches,Burning Pain,Burning Pains,Crushing Pain,Crushing Pains,Migratory Pain,Migratory Pains,Pains, Burning,Pains, Crushing,Pains, Migratory,Pains, Radiating,Pains, Splitting,Physical Suffering,Physical Sufferings,Radiating Pain,Radiating Pains,Splitting Pain,Splitting Pains,Sufferings, Physical
D010424	Pentobarbital	A short-acting barbiturate that is effective as a sedative and hypnotic (but not as an anti-anxiety) agent and is usually given orally. It is prescribed more frequently for sleep induction than for sedation but, like similar agents, may lose its effectiveness by the second week of continued administration. (From AMA Drug Evaluations Annual, 1994, p236)	Mebubarbital,Mebumal,Diabutal,Etaminal,Ethaminal,Nembutal,Pentobarbital Sodium,Pentobarbital, Monosodium Salt,Pentobarbitone,Sagatal,Monosodium Salt Pentobarbital
D002415	Cats	The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)	Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
D003655	Decerebrate State	A condition characterized by abnormal posturing of the limbs that is associated with injury to the brainstem. This may occur as a clinical manifestation or induced experimentally in animals. The extensor reflexes are exaggerated leading to rigid extension of the limbs accompanied by hyperreflexia and opisthotonus. This condition is usually caused by lesions which occur in the region of the brainstem that lies between the red nuclei and the vestibular nuclei. In contrast, decorticate rigidity is characterized by flexion of the elbows and wrists with extension of the legs and feet. The causative lesion for this condition is located above the red nuclei and usually consists of diffuse cerebral damage. (From Adams et al., Principles of Neurology, 6th ed, p358)	Decerebrate Posturing,Decorticate Rigidity,Decorticate State,Rigidity, Decerebrate,Rigidity, Decorticate,Decerebrate Posturings,Decerebrate Rigidity,Decerebrate States,Decorticate Rigidities,Decorticate States,Posturing, Decerebrate,Posturings, Decerebrate,Rigidities, Decorticate,State, Decerebrate,States, Decerebrate
D005073	Evoked Potentials, Somatosensory	The electric response evoked in the CEREBRAL CORTEX by stimulation along AFFERENT PATHWAYS from PERIPHERAL NERVES to CEREBRUM.	Somatosensory Evoked Potentials,Evoked Potential, Somatosensory,Somatosensory Evoked Potential
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013116	Spinal Cord	A cylindrical column of tissue that lies within the vertebral canal. It is composed of WHITE MATTER and GRAY MATTER.	Coccygeal Cord,Conus Medullaris,Conus Terminalis,Lumbar Cord,Medulla Spinalis,Myelon,Sacral Cord,Thoracic Cord,Coccygeal Cords,Conus Medullari,Conus Terminali,Cord, Coccygeal,Cord, Lumbar,Cord, Sacral,Cord, Spinal,Cord, Thoracic,Cords, Coccygeal,Cords, Lumbar,Cords, Sacral,Cords, Spinal,Cords, Thoracic,Lumbar Cords,Medulla Spinali,Medullari, Conus,Medullaris, Conus,Myelons,Sacral Cords,Spinal Cords,Spinali, Medulla,Spinalis, Medulla,Terminali, Conus,Terminalis, Conus,Thoracic Cords
D013823	Thermoreceptors	Cellular receptors which mediate the sense of temperature. Thermoreceptors in vertebrates are mostly located under the skin. In mammals there are separate types of thermoreceptors for cold and for warmth and NOCICEPTORS which detect cold or heat extreme enough to cause pain.	Thermoreceptor