Biomaterial Database

[Rhombencephalon and vasomotor reflexes to impulses of somatic A-fibers]. 1978

Iu B Gaĭlans, and E V Lukoshkova, and V M Khaiutin

Cats decerebrated so that the medulla oblongata remained connected with a greater or lesser part of the pons Varolli were immobilized with flaxedyl or succinylcholine; arterial pressure (AP) responses to impulses (at the frequency of 10 s-1) of different subgroups of the tibial nerve A-afferents were studied. Impulses of the Abeta + Adelta1-afferents and of the most excitable part of Adelta2-afferents lowered AP in all the animals. Addition of all the Adelta2-afferent impulses enhanced this AP fall in 79% of the cats and only 21% of them did it evoke a rise of AP. Inclusion of Adelta2-fiber impulses into the afferent inflow either did not alter the average AP decrease or evoked a weak, and only sometimes, a more pronounced AP rise. It was found crucial to keep intact the structures of the ponto-medullary junction, as well as the most rostral part of the medulla for sharp decrease of the pressor reflexes or for the appearance of the depressor ones, instead. Consequently, in this part of the hind brain there are structures exerting a tonic depressive influence on the exciting effect of the somatic A-afferent impulses on the vasoconstrictor neurons, thus unmasking the existence of the inhibitory component of their action on these neurons. In unanesthetized cats this action of the hind brain structures is tonically inhibited by the midbrain.

UI	MeSH Term	Description	Entries
D008526	Medulla Oblongata	The lower portion of the BRAIN STEM. It is inferior to the PONS and anterior to the CEREBELLUM. Medulla oblongata serves as a relay station between the brain and the spinal cord, and contains centers for regulating respiratory, vasomotor, cardiac, and reflex activities.	Accessory Cuneate Nucleus,Ambiguous Nucleus,Arcuate Nucleus of the Medulla,Arcuate Nucleus-1,External Cuneate Nucleus,Lateral Cuneate Nucleus,Nucleus Ambiguus,Ambiguus, Nucleus,Arcuate Nucleus 1,Arcuate Nucleus-1s,Cuneate Nucleus, Accessory,Cuneate Nucleus, External,Cuneate Nucleus, Lateral,Medulla Oblongatas,Nucleus, Accessory Cuneate,Nucleus, Ambiguous,Nucleus, External Cuneate,Nucleus, Lateral Cuneate
D008636	Mesencephalon	The middle of the three primitive cerebral vesicles of the embryonic brain. Without further subdivision, midbrain develops into a short, constricted portion connecting the PONS and the DIENCEPHALON. Midbrain contains two major parts, the dorsal TECTUM MESENCEPHALI and the ventral TEGMENTUM MESENCEPHALI, housing components of auditory, visual, and other sensorimoter systems.	Midbrain,Mesencephalons,Midbrains
D009434	Neural Pathways	Neural tracts connecting one part of the nervous system with another.	Neural Interconnections,Interconnection, Neural,Interconnections, Neural,Neural Interconnection,Neural Pathway,Pathway, Neural,Pathways, Neural
D009475	Neurons, Afferent	Neurons which conduct NERVE IMPULSES to the CENTRAL NERVOUS SYSTEM.	Afferent Neurons,Afferent Neuron,Neuron, Afferent
D011149	Pons	The front part of the hindbrain (RHOMBENCEPHALON) that lies between the MEDULLA and the midbrain (MESENCEPHALON) ventral to the cerebellum. It is composed of two parts, the dorsal and the ventral. The pons serves as a relay station for neural pathways between the CEREBELLUM to the CEREBRUM.	Pons Varolii,Ponte,Pons Varolius,Pontes,Varolii, Pons,Varolius, Pons
D012018	Reflex	An involuntary movement or exercise of function in a part, excited in response to a stimulus applied to the periphery and transmitted to the brain or spinal cord.
D001794	Blood Pressure	PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.	Systolic Pressure,Diastolic Pressure,Pulse Pressure,Pressure, Blood,Pressure, Diastolic,Pressure, Pulse,Pressure, Systolic,Pressures, Systolic
D001931	Brain Mapping	Imaging techniques used to colocalize sites of brain functions or physiological activity with brain structures.	Brain Electrical Activity Mapping,Functional Cerebral Localization,Topographic Brain Mapping,Brain Mapping, Topographic,Functional Cerebral Localizations,Mapping, Brain,Mapping, Topographic Brain
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