Biomaterial Database

Reticular neuron activities associated with locomotion in thalamic cats. 1982

M Shimamura, and I Kogure, and S Wada

Unit discharges of the reticular neurons and EMGs of extensors and flexors were recorded in the 4 limbs of thalamic cats during stepping on a motor-driven treadmill to study the functional role of the spino-bulbo-spinal (SBS) reflex in locomotion. (1) Reticular neurons showed alterations of increased or decreased discharge rate depending on the phase of the step cycle; they were divided into input (ascending), output (reticulospinal, R-S) and internuncial neurons underlying the SBS reflex. (2) R-S neurons showed increased spikes from the end o the stance to the beginning of the swing phase; in this period, flexor muscle EMGS were obtained. The spikes decreased or disappeared when extensor EMGs were observed. To analyze the relationship between activity in R-S neurons and flexor muscles, R-S neuron spikes were used for triggering and post-spike EMGs were averaged. Averaged EMGs of the correlated flexor revealed a 12 and 6 ms latency for hind- and forelimbs, respectively. Most R-S neurons elicited EMGs of flexor in muscles of one ipsilateral leg, some elicited flexor EMGs of both the ipsilateral fore-and hindlimbs. (3) Input neurons of the reticular formation from spinal ascending tracts fired spikes upon touching of the skin over the correlated limb. During stepping, they showed two types of response patterns: a burst discharge appeared for the leg which was swinging and touching the belt, the other pattern was of continuous discharges at the end of stance and at the beginning of swing phases. (4) Internuncial neurons which relay impulses between the input and output neurons also showed alternate firings depending on the phase of the step cycle. Spikes could be elicited by touching the skin over the 4 limbs. (5) The relationship among the activities of the 3 groups of reticular neurons was analyzed by the post- or pre-spike averaging technique and appropriate latency responses were obtained. (6) The results indicate that flexor EMGs were excited by cutaneous afferents via the SBS reflex in cats stepping on the treadmill. The role of the SBS reflex in locomotion is discussed.

UI	MeSH Term	Description	Entries
D007395	Interneurons	Most generally any NEURONS which are not motor or sensory. Interneurons may also refer to neurons whose AXONS remain within a particular brain region in contrast to projection neurons, which have axons projecting to other brain regions.	Intercalated Neurons,Intercalated Neuron,Interneuron,Neuron, Intercalated,Neurons, Intercalated
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
D009132	Muscles	Contractile tissue that produces movement in animals.	Muscle Tissue,Muscle,Muscle Tissues,Tissue, Muscle,Tissues, Muscle
D009474	Neurons	The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.	Nerve Cells,Cell, Nerve,Cells, Nerve,Nerve Cell,Neuron
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.
D012154	Reticular Formation	A region extending from the PONS & MEDULLA OBLONGATA through the MESENCEPHALON, characterized by a diversity of neurons of various sizes and shapes, arranged in different aggregations and enmeshed in a complicated fiber network.	Formation, Reticular,Formations, Reticular,Reticular Formations
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
D004576	Electromyography	Recording of the changes in electric potential of muscle by means of surface or needle electrodes.	Electromyogram,Surface Electromyography,Electromyograms,Electromyographies,Electromyographies, Surface,Electromyography, Surface,Surface Electromyographies
D005071	Evoked Potentials	Electrical responses recorded from nerve, muscle, SENSORY RECEPTOR, or area of the CENTRAL NERVOUS SYSTEM following stimulation. They range from less than a microvolt to several microvolts. The evoked potential can be auditory (EVOKED POTENTIALS, AUDITORY), somatosensory (EVOKED POTENTIALS, SOMATOSENSORY), visual (EVOKED POTENTIALS, VISUAL), or motor (EVOKED POTENTIALS, MOTOR), or other modalities that have been reported.	Event Related Potential,Event-Related Potentials,Evoked Potential,N100 Evoked Potential,P50 Evoked Potential,N1 Wave,N100 Evoked Potentials,N2 Wave,N200 Evoked Potentials,N3 Wave,N300 Evoked Potentials,N4 Wave,N400 Evoked Potentials,P2 Wave,P200 Evoked Potentials,P50 Evoked Potentials,P50 Wave,P600 Evoked Potentials,Potentials, Event-Related,Event Related Potentials,Event-Related Potential,Evoked Potential, N100,Evoked Potential, N200,Evoked Potential, N300,Evoked Potential, N400,Evoked Potential, P200,Evoked Potential, P50,Evoked Potential, P600,Evoked Potentials, N100,Evoked Potentials, N200,Evoked Potentials, N300,Evoked Potentials, N400,Evoked Potentials, P200,Evoked Potentials, P50,Evoked Potentials, P600,N1 Waves,N2 Waves,N200 Evoked Potential,N3 Waves,N300 Evoked Potential,N4 Waves,N400 Evoked Potential,P2 Waves,P200 Evoked Potential,P50 Waves,P600 Evoked Potential,Potential, Event Related,Potential, Event-Related,Potential, Evoked,Potentials, Event Related,Potentials, Evoked,Potentials, N400 Evoked,Related Potential, Event,Related Potentials, Event,Wave, N1,Wave, N2,Wave, N3,Wave, N4,Wave, P2,Wave, P50,Waves, N1,Waves, N2,Waves, N3,Waves, N4,Waves, P2,Waves, P50
D005552	Forelimb	A front limb of a quadruped. (The Random House College Dictionary, 1980)	Forelimbs