Biomaterial Database

Synaptic transmission between ventrolateral funiculus axons and lumbar motoneurons in the isolated spinal cord of the neonatal rat. 1994

M Pinco, and A Lev-Tov

Department of Anatomy, Hebrew University Medical School, Jerusalem, Israel.

1. We studied the projections of ventrolateral funiculus (VLF) axons to lumbar motoneurons in the in vitro spinal cord preparation of 1- to 6-day-old rats using extracellular and sharp-electrode intracellular recordings. 2. Ipsilateral and contralateral VLF projections to lumbar motoneurons (L4-L5) could be activated in the neonatal rat by stimulation of the surgically peeled VLF at the rostral (L1-L2) and caudal lumbar (L6) cord. Motoneurons were activated ipsilaterally through short- and long-latency projections in all cases and contralaterally through long-latency projections in most cases. 3. Suppression of the excitatory components of VLF postsynaptic potentials (PSPs) by application of the specific antagonists of N-methyl D-aspartate (NMDA) and non-NMDA receptors, 2-amino-5-phosphonovaleric acid (APV) and 6-cyano-7-nitroquin-oxaline-2,3-dione (CNQX), revealed depolarizing PSPs that could be reversed at -55 to -60 mV by injection of depolarizing current steps to the motoneurons. These depolarizing PSPs were blocked by addition of strychnine and bicuculline and are therefore suggested to be glycine and gamma-aminobutyric acid-A (GABAA) receptor-mediated inhibitory PSPs. The identity of a small (< or = 0.2 mV) residual depolarizing component that persisted in the presence of APV, CNQX, strychnine, and bicuculline remains to be determined. 4. Short-latency excitatory PSPs (EPSPs) could be resolved from the ipsilaterally elicited VLF PSPs after the reduction of the polysynaptic activity in the preparation by administration of mephenesin, which was followed by suppression of the glycine and GABAA receptor-mediated components of the PSPs by bath application of strychnine and bicuculline. The latencies of these EPSPs were similar to those of the monosynaptic dorsal root afferent EPSPs recorded from the same motoneurons. These short-latency VLF EPSPs were shortened by the NMDA antagonist APV and revealed an NMDA receptor-mediated component after administration of the non-NMDA receptor antagonist CNQX. Addition of the GABAB receptor agonist L-(-) baclofen or the glutamate analogue L-2-amino-4-phosphonobutyric acid (L-AP4) attenuated the pharmacologically resolved short-latency EPSPs.(ABSTRACT TRUNCATED AT 400 WORDS)

UI	MeSH Term	Description	Entries
D007839	Functional Laterality	Behavioral manifestations of cerebral dominance in which there is preferential use and superior functioning of either the left or the right side, as in the preferred use of the right hand or right foot.	Ambidexterity,Behavioral Laterality,Handedness,Laterality of Motor Control,Mirror Writing,Laterality, Behavioral,Laterality, Functional,Mirror Writings,Motor Control Laterality,Writing, Mirror,Writings, Mirror
D008564	Membrane Potentials	The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).	Resting Potentials,Transmembrane Potentials,Delta Psi,Resting Membrane Potential,Transmembrane Electrical Potential Difference,Transmembrane Potential Difference,Difference, Transmembrane Potential,Differences, Transmembrane Potential,Membrane Potential,Membrane Potential, Resting,Membrane Potentials, Resting,Potential Difference, Transmembrane,Potential Differences, Transmembrane,Potential, Membrane,Potential, Resting,Potential, Transmembrane,Potentials, Membrane,Potentials, Resting,Potentials, Transmembrane,Resting Membrane Potentials,Resting Potential,Transmembrane Potential,Transmembrane Potential Differences
D009046	Motor Neurons	Neurons which activate MUSCLE CELLS.	Neurons, Motor,Alpha Motorneurons,Motoneurons,Motor Neurons, Alpha,Neurons, Alpha Motor,Alpha Motor Neuron,Alpha Motor Neurons,Alpha Motorneuron,Motoneuron,Motor Neuron,Motor Neuron, Alpha,Motorneuron, Alpha,Motorneurons, Alpha,Neuron, Alpha Motor,Neuron, Motor
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
D009435	Synaptic Transmission	The communication from a NEURON to a target (neuron, muscle, or secretory cell) across a SYNAPSE. In chemical synaptic transmission, the presynaptic neuron releases a NEUROTRANSMITTER that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across ELECTRICAL SYNAPSES.	Neural Transmission,Neurotransmission,Transmission, Neural,Transmission, Synaptic
D011930	Reaction Time	The time from the onset of a stimulus until a response is observed.	Response Latency,Response Speed,Response Time,Latency, Response,Reaction Times,Response Latencies,Response Times,Speed, Response,Speeds, Response
D000375	Aging	The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.	Senescence,Aging, Biological,Biological Aging
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
D000831	Animals, Newborn	Refers to animals in the period of time just after birth.	Animals, Neonatal,Animal, Neonatal,Animal, Newborn,Neonatal Animal,Neonatal Animals,Newborn Animal,Newborn Animals
D001369	Axons	Nerve fibers that are capable of rapidly conducting impulses away from the neuron cell body.	Axon