Biomaterial Database

Antidromic discharges in dorsal roots of decerebrate cats. I. Studies at rest and during fictive locomotion. 1999

I Beloozerova, and S Rossignol

Centre de Recherche en Sciences Neurologiques, Faculté de Médecine, Pavillon Paul-G.-Desmarais, 2960 Chemin de la Tour, Université de Montréal, Montréal, Québec, Canada.

Spontaneous rhythmic antidromic discharges have previously been recorded in proximal stumps of cut dorsal roots during locomotion (real and fictive). The goals of the present study were to elucidate (1) whether both orthodromic and antidromic discharges occur in the same dorsal root filament and (2) whether orthodromic discharges have an influence upon antidromic discharges of units in the same filament. Unitary activity was recorded in 70 uncut dorsal root filaments (L6-S1) in 15 decerebrate cats using bipolar Ag/AgCl electrodes. Spikes with similar wave shapes were considered to represent the activity of single units. Spike-triggered averaging (STA), local anaesthesia and transection of filaments were used to determine the direction of propagation of spikes. Spikes with different initial electrical polarities were found in most of the filaments and shown to propagate in opposite directions at rest and during fictive locomotion. On average, there were 38%+/-S.D. 23% antidromically discharging units per filament and their mean conduction velocity was 55 m/s+/-S.D. 25 m/s. After blocking orthodromic activity of the whole filament by a transection or local anesthesia applied distally to the recording site, changes were seen in the antidromic discharges of some units suggesting that spontaneous orthodromic discharges normally seen in the filament may influence the antidromic discharges of some units. Moreover, out of 27 antidromic units recorded during fictive locomotion, 12 were rhythmically modulated with peak discharges occurring in various parts of the locomotor cycle. We conclude that, in uncut dorsal roots, there is a normal coexistence of spontaneous orthodromic and antidromic discharges revealed by STA and that there is an interaction between spontaneous orthodromic and antidromic discharges.

UI	MeSH Term	Description	Entries
D008012	Lidocaine	A local anesthetic and cardiac depressant used as an antiarrhythmia agent. Its actions are more intense and its effects more prolonged than those of PROCAINE but its duration of action is shorter than that of BUPIVACAINE or PRILOCAINE.	Lignocaine,2-(Diethylamino)-N-(2,6-Dimethylphenyl)Acetamide,2-2EtN-2MePhAcN,Dalcaine,Lidocaine Carbonate,Lidocaine Carbonate (2:1),Lidocaine Hydrocarbonate,Lidocaine Hydrochloride,Lidocaine Monoacetate,Lidocaine Monohydrochloride,Lidocaine Monohydrochloride, Monohydrate,Lidocaine Sulfate (1:1),Octocaine,Xylesthesin,Xylocaine,Xylocitin,Xyloneural
D008124	Locomotion	Movement or the ability to move from one place or another. It can refer to humans, vertebrate or invertebrate animals, and microorganisms.	Locomotor Activity,Activities, Locomotor,Activity, Locomotor,Locomotor Activities
D008297	Male		Males
D009433	Neural Inhibition	The function of opposing or restraining the excitation of neurons or their target excitable cells.	Inhibition, Neural
D009475	Neurons, Afferent	Neurons which conduct NERVE IMPULSES to the CENTRAL NERVOUS SYSTEM.	Afferent Neurons,Afferent Neuron,Neuron, Afferent
D012146	Rest	Freedom from activity.	Rests
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
D004594	Electrophysiology	The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
D005260	Female		Females