In situ hybridization analysis of AMPA receptor subunit gene expression in the developing rat spinal cord

The AMPA type glutamate receptors mediate the majority of fast synaptic transmission in the vertebrate nervous system. Whereas mammals have four subunit genes, Gria1-4, zebrafish has retained a duplicated set of eight genes named gria1-4a and b. We give here a detailed overview of the expression patterns of all eight zebrafish subunits within the developing central nervous system and sensory organs at 24, 48, and 72 hr after fertilization. Expression domains include distinct neuronal subsets in the developing forebrain, midbrain, hindbrain, and spinal cord, as well as in the ganglion-and inner nuclear layers of the retina. As a general rule, each pair of duplicated gria genes is differentially expressed, indicating subfunctionalization of AMPA receptor subunit expression in the teleost lineage. Our findings suggest that zebrafish can serve as a useful model system to investigate the role of AMPA receptors and their differential expression in the vertebrate nervous system. Developmental Dynamics 237:788 -799, 2008.

show abstract

“…1-4). This finding is similar to the situation observed in the human and rat spinal cord development (Jakowec et al, 1995;Akesson et al, 2000).…”

Section: Discussionsupporting

confidence: 91%

Expression of the eight AMPA receptor subunit genes in the developing central nervous system and sensory organs of zebrafish

Hoppmann

Søviknes

et al. 2008

Developmental Dynamics

View full text Add to dashboard Cite

show abstract

“…AMPA receptors underlie developmental modifications such as Q/R editing and alternative splicing. During embryogenesis, low levels of unedited GluR2 can be detected, and GluR1 is mostly spliced to the flip variant (Burnashev et al, 1992;Nutt and Kamboj, 1994;Jakowec et al, 1995). However, we could not detect any striking differences in the modulation of these receptor variants in coexpression with ␥4, the predominant TARP in this developmental period (Tomita et al, 2003), compared with the modulation of subunits predominantly expressed in the adult.…”

Section: Discussioncontrasting

confidence: 69%

Electrophysiological Properties of AMPA Receptors Are Differentially Modulated Depending on the Associated Member of the TARP Family

Kott¹,

Werner²,

Körber³

et al. 2007

J. Neurosci.

View full text Add to dashboard Cite

The family of AMPA receptors is encoded by four genes that are differentially spliced to result in the flip or flop versions of the four subunits GluR1 to GluR4. GluR2 is further modified at the so-called Q/R site by posttranscriptional RNA editing. Delivery of AMPA receptors to the plasma membrane and synaptic trafficking are controlled by transmembrane AMPA receptor regulatory proteins (TARPs). Additionally, TARPs influence essential electrophysiological properties of AMPA receptor channels such as desensitization and agonist efficacies. Here, we compare the influence of all known TARPs (␥2, ␥3, ␥4, and ␥8) on agonist-induced currents of the four AMPA receptor subunits, including flip and flop splice variants and editing variants. We show that, although agonist-induced currents of all homomeric AMPA receptor subunits as well as all heteromeric combinations tested are significantly potentiated when coexpressed with members of the TARP family in Xenopus laevis oocytes, the extent of TARP-mediated increase in agonist-induced responses is highly dependent on both the AMPA receptor subunit and the coexpressed TARP. Moreover, we demonstrate that the splice variant of the AMPA receptor plays a key role in determining the modulation of electrophysiological properties by associated TARPs. We furthermore present evidence that individual TARP-AMPA receptor interactions control the degree of desensitization of AMPA receptors. Consequently, because of their subunit-specific impact on the electrophysiological properties, TARPs play a major role as modulatory subunits of AMPA receptors and thus contribute to the functional diversity of AMPA receptors encountered in the CNS.

show abstract

“…370, 427), combined with molecular physiological approaches similar to those used recently to introduce cDNA for the GluR1 subunit into motoneurons in vivo and in vitro (906), promise further insight into the role of specific glutamate subunits in controlling motoneuron excitability (906). Moreover, the implication that differential susceptibility of motoneurons to degeneration in motoneuron diseases may in part be attributable to molecular diversity of glutamate receptors (193,559,1082,1134,1135,1258,1366) should accelerate discovery in this area.…”

Section: A Glutamate: Ionotropic Actionsmentioning

confidence: 99%

“…Activity-dependent restructuring of neuronal circuits has primarily been examined for thalamic and cortical sensory maps, but evidence for its role in motoneuron development is growing (361, 487,599,750,899,900). Developmental alterations in motoneuronal glutamate receptor subunit expression (558,559), binding profiles (432,595,601), changing contributions of receptor subtypes to synaptic transmission (719,1433), and reductions in NMDA-induced currents (516, 876) underscore not only the potential for developmental change in motoneuron excitability but the possible contribution of glutamate receptors to activity-dependent development of motoneurons.…”

Section: Role Of Glutamate In Activity-dependent Development Of Motonmentioning

confidence: 99%

Synaptic Control of Motoneuronal Excitability

Rekling

Funk

Bayliss

et al. 2000

Physiological Reviews

531

482

View full text Add to dashboard Cite

Movement, the fundamental component of behavior and the principal extrinsic action of the brain, is produced when skeletal muscles contract and relax in response to patterns of action potentials generated by motoneurons. The processes that determine the firing behavior of motoneurons are therefore important in understanding the transformation of neural activity to motor behavior. Here, we review recent studies on the control of motoneuronal excitability, focusing on synaptic and cellular properties. We first present a background description of motoneurons: their development, anatomical organization, and membrane properties, both passive and active. We then describe the general anatomical organization of synaptic input to motoneurons, followed by a description of the major transmitter systems that affect motoneuronal excitability, including ligands, receptor distribution, pre-and postsynaptic actions, signal transduction, and functional role. Glutamate is the main excitatory, and GABA and glycine are the main inhibitory transmitters acting through ionotropic receptors. These amino acids signal the principal motor commands from peripheral, spinal, and supraspinal structures. Amines, such as serotonin and norepinephrine, and neuropeptides, as well as the glutamate and GABA acting at metabotropic receptors, modulate motoneuronal excitability through pre-and postsynaptic actions. Acting principally via second messenger systems, their actions converge on common effectors, e.g., leak K + current, cationic inward current, hyperpolarization-activated inward current, Ca 2+ channels, or presynaptic release processes. Together, these numerous inputs mediate and modify incoming motor commands, ultimately generating the coordinated firing patterns that underlie muscle contractions during motor behavior.

show abstract

In situ hybridization analysis of AMPA receptor subunit gene expression in the developing rat spinal cord

Cited by 99 publications

References 45 publications

Expression of the eight AMPA receptor subunit genes in the developing central nervous system and sensory organs of zebrafish

Expression of the eight AMPA receptor subunit genes in the developing central nervous system and sensory organs of zebrafish

Electrophysiological Properties of AMPA Receptors Are Differentially Modulated Depending on the Associated Member of the TARP Family

Synaptic Control of Motoneuronal Excitability

Contact Info

Product

Resources

About