Biomaterial Database

Properties and plasticity of synaptic inputs to rat dorsal column neurones recorded in vitro. 2001

A Nuñez, and W Buño

Departamento de Morfología, Facultad de Medicina, Universidad Autónoma de Madrid, Arzobispo Morcillo s/n 28029 Madrid, Spain. angel.nunez@uam.es

1. The mechanisms regulating the flow of sensory signals and their modification by synaptic interactions in the dorsal column nuclei are incompletely understood. Therefore, we examined the interactions between EPSPs evoked by stimulation of dorsal column and corticofugal fibres in the dorsal column nuclei cells using an in vitro slice technique. 2. Dorsal column EPSPs had briefer durations at depolarised membrane potentials than corticofugal EPSPs. Superfusion of the NMDA receptor antagonist 2D(-)-2-amino-5-phosphonovaleric acid (AP5) did not modify dorsal column EPSPs but reduced corticofugal EPSPs. Application of the AMPA/kainate receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) abolished both dorsal column and corticofugal EPSPs in cells held at the resting potential. Therefore, dorsal column EPSPs were mediated by non-NMDA receptors but corticofugal EPSPs revealed both non-NMDA- and NMDA-dependent components. 3. Paired-pulse stimulation of dorsal column fibres elicited a depression of the second EPSP at pulse intervals of < 50 ms; however, paired-pulse stimulation of corticofugal fibres evoked facilitation of the second EPSP at pulse intervals of < 30 ms. When stimulation of the corticofugal fibres preceded stimulation of the dorsal column fibres, facilitation of the dorsal column EPSP was observed at pulse intervals of < 100 ms. This facilitation was blocked at hyperpolarised membrane potentials or in the presence of AP5, suggesting activation of NMDA receptors. There was a depression of corticofugal EPSPs by previous dorsal column stimulation. 4. Dorsal column EPSPs were gradually depressed during stimulation with barrages at frequencies of > 10 Hz, while corticofugal EPSPs were facilitated and summated at frequencies > 30 Hz. Hyperpolarisation and application of AP5 prevented the facilitation of corticofugal EPSPs. High frequency stimulation of the corticofugal input elicited a short-lasting AP5-sensitive facilitation of both corticofugal and dorsal column EPSPs. Depolarising current facilitated dorsal column EPSPs but not corticofugal EPSPs. 5. These results indicate that synaptic interactions include different forms of activity-dependent synaptic plasticity, with the participation of NMDA receptors and probably Ca(2+) inflow through voltage-gated channels. These complex synaptic interactions may represent the cellular substrate of the integrative function of the dorsal column nuclei observed in vivo.

UI	MeSH Term	Description	Entries
D009473	Neuronal Plasticity	The capacity of the NERVOUS SYSTEM to change its reactivity as the result of successive activations.	Brain Plasticity,Plasticity, Neuronal,Axon Pruning,Axonal Pruning,Dendrite Arborization,Dendrite Pruning,Dendritic Arborization,Dendritic Pruning,Dendritic Remodeling,Neural Plasticity,Neurite Pruning,Neuronal Arborization,Neuronal Network Remodeling,Neuronal Pruning,Neuronal Remodeling,Neuroplasticity,Synaptic Plasticity,Synaptic Pruning,Arborization, Dendrite,Arborization, Dendritic,Arborization, Neuronal,Arborizations, Dendrite,Arborizations, Dendritic,Arborizations, Neuronal,Axon Prunings,Axonal Prunings,Brain Plasticities,Dendrite Arborizations,Dendrite Prunings,Dendritic Arborizations,Dendritic Prunings,Dendritic Remodelings,Network Remodeling, Neuronal,Network Remodelings, Neuronal,Neural Plasticities,Neurite Prunings,Neuronal Arborizations,Neuronal Network Remodelings,Neuronal Plasticities,Neuronal Prunings,Neuronal Remodelings,Neuroplasticities,Plasticities, Brain,Plasticities, Neural,Plasticities, Neuronal,Plasticities, Synaptic,Plasticity, Brain,Plasticity, Neural,Plasticity, Synaptic,Pruning, Axon,Pruning, Axonal,Pruning, Dendrite,Pruning, Dendritic,Pruning, Neurite,Pruning, Neuronal,Pruning, Synaptic,Prunings, Axon,Prunings, Axonal,Prunings, Dendrite,Prunings, Dendritic,Prunings, Neurite,Prunings, Neuronal,Prunings, Synaptic,Remodeling, Dendritic,Remodeling, Neuronal,Remodeling, Neuronal Network,Remodelings, Dendritic,Remodelings, Neuronal,Remodelings, Neuronal Network,Synaptic Plasticities,Synaptic Prunings
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
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
D013569	Synapses	Specialized junctions at which a neuron communicates with a target cell. At classical synapses, a neuron's presynaptic terminal releases a chemical transmitter stored in synaptic vesicles which diffuses across a narrow synaptic cleft and activates receptors on the postsynaptic membrane of the target cell. The target may be a dendrite, cell body, or axon of another neuron, or a specialized region of a muscle or secretory cell. Neurons may also communicate via direct electrical coupling with ELECTRICAL SYNAPSES. Several other non-synaptic chemical or electric signal transmitting processes occur via extracellular mediated interactions.	Synapse
D015763	2-Amino-5-phosphonovalerate	The D-enantiomer is a potent and specific antagonist of NMDA glutamate receptors (RECEPTORS, N-METHYL-D-ASPARTATE). The L form is inactive at NMDA receptors but may affect the AP4 (2-amino-4-phosphonobutyrate; APB) excitatory amino acid receptors.	2-Amino-5-phosphonopentanoic Acid,2-Amino-5-phosphonovaleric Acid,2-APV,2-Amino-5-phosphonopentanoate,5-Phosphononorvaline,d-APV,dl-APV,2 Amino 5 phosphonopentanoate,2 Amino 5 phosphonopentanoic Acid,2 Amino 5 phosphonovalerate,2 Amino 5 phosphonovaleric Acid,5 Phosphononorvaline
D017208	Rats, Wistar	A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.	Wistar Rat,Rat, Wistar,Wistar Rats
D051381	Rats	The common name for the genus Rattus.	Rattus,Rats, Laboratory,Rats, Norway,Rattus norvegicus,Laboratory Rat,Laboratory Rats,Norway Rat,Norway Rats,Rat,Rat, Laboratory,Rat, Norway,norvegicus, Rattus
D018691	Excitatory Amino Acid Antagonists	Drugs that bind to but do not activate excitatory amino acid receptors, thereby blocking the actions of agonists.	Amino Acids, Excitatory, Antagonists,Excitatory Amino Acid Antagonist,Glutamate Antagonist,Glutamate Antagonists,Glutamate Receptor Antagonist,Amino Acid Antagonists, Excitatory,Antagonists, Excitatory Amino Acid,EAA Antagonists,Glutamate Receptor Antagonists,Antagonist, Glutamate,Antagonist, Glutamate Receptor,Antagonists, EAA,Antagonists, Glutamate,Antagonists, Glutamate Receptor,Receptor Antagonist, Glutamate,Receptor Antagonists, Glutamate
D018750	6-Cyano-7-nitroquinoxaline-2,3-dione	A potent excitatory amino acid antagonist with a preference for non-NMDA iontropic receptors. It is used primarily as a research tool.	CNQX,1,4-dihydro-2,3-dihydroxy-7-nitro-6-quinoxalinecarbonitrile,6-Cyano-2,3-dihydroxy-7-nitroquinoxaline,FG-9065,6 Cyano 2,3 dihydroxy 7 nitroquinoxaline,6 Cyano 7 nitroquinoxaline 2,3 dione,FG 9065,FG9065