Postnatal Development of Inhibitory Synaptic Transmission in the Rostral Nucleus of the Solitary Tract

2001 ◽  
Vol 85 (5) ◽  
pp. 2203-2212 ◽  
Author(s):  
Gintautas Grabauskas ◽  
Robert M. Bradley
Keyword(s):  
Synaptic Transmission ◽  
Postnatal Development ◽  
Age Groups ◽  
Brain Slices ◽  
Single Stimulus ◽  
Synaptic Activity ◽  
Membrane Properties ◽  
Tetanic Stimulation ◽  
Solitary Tract ◽  
Inhibitory Synaptic Transmission

To explore the postnatal development of inhibitory synaptic activity in the rostral (gustatory) nucleus of the solitary tract (rNST), whole cell and gramicidin perforated patch-clamp recordings were made in five age groups of rats [ postnatal day 0–7 ( P0–7), P8–14, P15–21, P22–30, and P > 55]. The passive membrane properties of the developing rNST neurons as well as the electrophysiological and pharmacological characteristics of single and tetanic stimulus-evoked inhibitory postsynaptic potentials (IPSPs) were studied in brain slices under glutamate receptor blockade. During the first postnatal weeks, significant changes in resting membrane potential, spontaneous activity, input resistance, and neuron membrane time constant of the rNST neurons occurred. Although all the IPSPs recorded were hyperpolarizing, the rise and decay time constants of the single stimulus shock-evoked IPSPs decreased, and the inhibition response–concentration function to the γ-aminobutyric acid (GABA) receptor antagonist bicuculline methiodide (BMI) shifted to the left during development. In P0–7 and P8–14, but not in older animals, the IPSPs had a BMI-insensitive component that was sensitive to block by picrotoxin, suggesting a transient expression of GABAC receptors. Tetanic stimulation resulted in both short- and long-term changes of inhibitory synaptic transmission in the rNST. For P0–7 and P8–14 animals tetanic stimulation resulted in a sustained hyperpolarization that was maintained for some time after termination of the tetanic stimulation. In contrast, tetanic stimulation of neurons in P15–21 and older animals resulted in hyperpolarization that was not sustained but decayed back to a more positive level with an exponential time course. Tetanic stimulation resulted in potentiation of single stimulus shock-evoked IPSPs in ∼50% of neurons in all age groups. These developmental changes in inhibitory synaptic transmission in the rNST may play an important role in shaping synaptic activity in early development of the rat gustatory system during a time of maturation of taste preferences and aversions.

scholarly journals GPI-1046 Increases Presenilin-1 Expression and Restores NMDA Channel Activity

2010 ◽  
Vol 37 (4) ◽  
pp. 457-467 ◽  
Author(s):  
Joseph P. Steiner ◽  
Kathryn B. Payne ◽  
Christopher Drummond Main ◽  
Sabrina D'Alfonso ◽  
Kirsten X. Jacobsen ◽  
...  
Keyword(s):  
Nmda Receptor ◽  
Synaptic Transmission ◽  
Brain Slices ◽  
Synaptic Activity ◽  
Presenilin 1 ◽  
Receptor Function ◽  
Channel Function ◽  
Nmda Channel ◽  
Nmda Receptor Function ◽  
6 Hydroxydopamine

Background:Previously we showed that 6-hydroxydopamine lesions of the substantia nigra eliminate corticostriatal LTP and that the neuroimmunolophilin ligand (NIL), GPI-1046, restores LTP.Methods:We used cDNA microarrays to determine what mRNAs may be over- or under-expressed in response to lesioning and/or GPI-1046 treatment. Patch clamp recordings were performed to investigate changes in NMDA channel function before and after treatments.Results:We found that 51 gene products were differentially expressed. Among these we found that GPI-1046 treatment up-regulated presenilin-1 (PS-1) mRNA abundance. This finding was confirmed using QPCR. PS-1 protein was also shown to be over-expressed in the striatum of lesioned/GPI-1046-treated rats. As PS-1 has been implicated in controlling NMDA-receptor function and LTP is reduced by lesioning we assayed NMDA mediated synaptic activity in striatal brain slices. The lesion-induced reduction of dopaminergic innervation was accompanied by the near complete loss of NDMA receptor-mediated synaptic transmission between the cortex and striatum. GPI-1046 treatment of the lesioned rats restored NMDA-mediated synaptic transmission but not the dopaminergic innervation. Restoration of NDMA channel function was apparently specific as the sodium channel current density was also reduced due to lesioning but GPI-1046 did not reverse this effect. We also found that restoration of NMDA receptor function was also not associated with either an increase in NMDA receptor mRNA or protein expression.Conclusion:As it has been previously shown that PS-1 is critical for normal NMDA receptor function, our data suggest that the improvement of excitatory neurotransmission occurs through the GPI-1046-induced up-regulation of PS-1.

Altered desensitization produces enhancement of EPSPs in neocortical neurons

1994 ◽  
Vol 72 (2) ◽  
pp. 1032-1036 ◽  
Author(s):  
M. R. Pelletier ◽  
J. J. Hablitz
Keyword(s):  
Nmda Receptors ◽  
Time Course ◽  
Glutamate Release ◽  
Epileptiform Activity ◽  
Brain Slices ◽  
Synaptic Activity ◽  
Membrane Properties ◽  
Repetitive Firing ◽  
Resting Membrane Potential ◽  
Bath Application

1. Neocortical brain slices were prepared from rats (35–50 days of age) and maintained in vitro. Intracellular recordings were obtained from neurons in cortical layers II/III. The effect of bath application of cyclothiazide (CYZ), a potent blocker of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptor desensitization, on evoked synaptic activity and passive membrane properties was investigated. 2. Bath application of CYZ did not significantly affect resting membrane potential, input resistance, or repetitive firing. CYZ increased both the amplitude and duration of evoked excitatory postsynaptic potentials (EPSPs). Polysynaptic responses were also augumented. These effects persisted after the blockade of N-methyl-D-aspartate (NMDA) receptors with D-2-amino-5-phosphonovaleric acid (D-APV). The magnitude of these effects appeared to vary directly with stimulation intensity and presumably, amount of glutamate release. 3. Epileptiform activity was induced by bath application of bicuculline methiodide. The amplitude and duration of evoked paroxysmal discharges were increased by CYZ. Similar results were seen in presence of D-APV. 4. These results indicate that CYZ has significant effects on synaptic transmission. Desensitization of non-NMDA receptors may be an important mechanism for determining the time course of EPSPs and in curtailing epileptiform responses in the rat neocortex.

Dopamine Modulates Synaptic Transmission in the Nucleus of the Solitary Tract

2002 ◽  
Vol 88 (5) ◽  
pp. 2736-2744 ◽  
Author(s):  
David D. Kline ◽  
Kristin N. Takacs ◽  
Eckhard Ficker ◽  
Diana L. Kunze
Keyword(s):  
Synaptic Transmission ◽  
Nucleus Tractus Solitarius ◽  
Integration Site ◽  
Cell Voltage ◽  
Input Resistance ◽  
D2 Receptors ◽  
Synaptic Activity ◽  
Solitary Tract ◽  
Afferent Fibers ◽  
Sensory Fibers

10.1152/jn.00224.2002. Dopamine (DA) modulates the cardiorespiratory reflex by peripheral and central mechanisms. The aim of this study was to examine the role of DA in synaptic transmission of the nucleus tractus solitarius (NTS), the major integration site for cardiopulmonary reflexes. To examine DA's role, we used whole cell, voltage-clamp recordings in a rat horizontal brain stem slice. Solitary tract stimulation evoked excitatory postsynaptic currents (EPSCs) that were reduced to 70 ± 5% of control by DA (100 μM). The reduction in EPSCs by DA was accompanied by a decrease in the paired pulse depression ratio with little or no change in input resistance or EPSC decay, suggesting a presynaptic mechanism. The D1-like agonist SKF 38393 Br (30 μM) did not alter EPSC amplitude, whereas the D2-like agonist, quinpirole HCl (30 μM), depressed EPSCs to 73 ± 4% of control. The D2-like receptor antagonist, sulpiride (20 μM), abolished DA modulation of EPSCs. Most importantly, sulpiride alone increased EPSCs to 131 ± 10% of control, suggesting a tonic D2-like modulation of synaptic transmission in the NTS. Examination of spontaneous EPSCs revealed DA reversibly decreased the frequency of events from 9.4 ± 2.2 to 6.2 ± 1.4 Hz. Sulpiride, however, did not alter spontaneous events. Immunohistochemistry of NTS slices demonstrated that D2 receptors colocalized with synaptophysin and substance P, confirming a presynaptic distribution. D2 receptors also localized to cultured petrosal neurons, the soma of presynaptic afferent fibers. In the petrosal neurons, D2 was found in cells that were TH-immunopositive, suggesting they were chemoreceptor afferent fibers. These results demonstrate that DA tonically modulates synaptic activity between afferent sensory fibers and secondary relay neurons in the NTS via a presynaptic D2-like mechanism.

scholarly journals Postnatal development of inhibitory synaptic transmission to superior salivatory neurons in rats

2009 ◽  
Vol 56 (Supplement) ◽  
pp. 270-272
Author(s):  
Yoshihiro Mitoh ◽  
Makoto Funahashi ◽  
Masako Fujita ◽  
Motoi Kobashi ◽  
Ryuji Matsuo
Keyword(s):  
Synaptic Transmission ◽  
Postnatal Development ◽  
Inhibitory Synaptic Transmission

scholarly journals Neuroligin3 splice isoforms shape inhibitory synaptic function in the mouse hippocampus

2020 ◽  
Vol 295 (25) ◽  
pp. 8589-8595 ◽  
Author(s):  
Motokazu Uchigashima ◽  
Ming Leung ◽  
Takuya Watanabe ◽  
Amy Cheung ◽  
Timmy Le ◽  
...  
Keyword(s):  
Synaptic Transmission ◽  
Single Cell ◽  
Pyramidal Neurons ◽  
Autism Spectrum ◽  
Synaptic Function ◽  
Synaptic Activity ◽  
Dependent Manner ◽  
Splice Isoforms ◽  
Inhibitory Synaptic Transmission ◽  
Ca1 Pyramidal Neurons

Synapse formation is a dynamic process essential for the development and maturation of the neuronal circuitry in the brain. At the synaptic cleft, trans-synaptic protein–protein interactions are major biological determinants of proper synapse efficacy. The balance of excitatory and inhibitory synaptic transmission (E-I balance) stabilizes synaptic activity, and dysregulation of the E-I balance has been implicated in neurodevelopmental disorders, including autism spectrum disorders. However, the molecular mechanisms underlying the E-I balance remain to be elucidated. Here, using single-cell transcriptomics, immunohistochemistry, and electrophysiology approaches to murine CA1 pyramidal neurons obtained from organotypic hippocampal slice cultures, we investigate neuroligin (Nlgn) genes that encode a family of postsynaptic adhesion molecules known to shape excitatory and inhibitory synaptic function. We demonstrate that the NLGN3 protein differentially regulates inhibitory synaptic transmission in a splice isoform–dependent manner at hippocampal CA1 synapses. We also found that distinct subcellular localizations of the NLGN3 isoforms contribute to the functional differences observed among these isoforms. Finally, results from single-cell RNA-Seq analyses revealed that Nlgn1 and Nlgn3 are the major murine Nlgn genes and that the expression levels of the Nlgn splice isoforms are highly diverse in CA1 pyramidal neurons. Our results delineate isoform-specific effects of Nlgn genes on the E-I balance in the murine hippocampus.

Developmental changes in NMDA and non-NMDA receptor-mediated synaptic potentials in rat neocortex

1993 ◽  
Vol 69 (1) ◽  
pp. 230-240 ◽  
Author(s):  
E. C. Burgard ◽  
J. J. Hablitz
Keyword(s):  
Nmda Receptor ◽  
Cortical Neurons ◽  
Age Groups ◽  
Reversal Potential ◽  
Membrane Potentials ◽  
Synaptic Activity ◽  
Membrane Properties ◽  
Inward Rectification ◽  
Gabaa Receptor Antagonist

1. In vitro slices of frontal neocortex were prepared from rat pups 3–14 days of age. Whole-cell patch-clamp recordings were obtained from layer II-III cortical neurons, and measurements of passive membrane properties were made. The development of evoked synaptic excitation and inhibition was also examined with the use of current- and voltage-clamp techniques. 2. Pharmacological separation of excitatory synaptic activity into both N-methyl-D-aspartate (NMDA) and non-NMDA receptor-mediated components was accomplished by application of D(-)2-amino-5-phosphonovaleric acid (APV), D(-)2-amino-7-phosphonoheptanoic acid (AP7), and 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). Inhibitory synaptic events were described according to their reversal potentials and modulation by the GABAA receptor antagonist bicuculline methiodide (BMI). 3. Pups were grouped into three categories on the basis of age: postnatal day (PN) 3–5, PN 6–8, and PN 9–14. In slices from PN 3–5 pups, neurons exhibited high input resistances (Rn) and relatively low resting membrane potentials (RMP). Rns decreased, and RMPs became more negative with development. At all ages studied, current-voltage relationships measured in current clamp were relatively linear, with inward rectification observed in some neurons at hyperpolarized membrane potentials. Neurons in each group were capable of firing overshooting action potentials. 4. Local stimulation in layer IV-V at 0.033 Hz elicited depolarizing excitatory postsynaptic potentials (EPSPs) in neurons from all three age groups. In PN 3–5 neurons, EPSPs were characterized by a long duration and latency to peak. By PN 6–8, EPSPs had decreased significantly in both duration and latency-to-peak. Some neurons responded with a single-component EPSP, whereas others exhibited multicomponent EPSPs consisting of distinct early and late components. In PN 3–5 neurons, increasing the frequency of stimulation from 0.033 to 1 Hz resulted in an overall decrease in the amplitude of the entire EPSP, whereas in PN 6–8 neurons the main decrease was observed in the late EPSP. 5. Excitatory postsynaptic currents (EPSCs) recorded in both PN 3–5 and PN 6–8 neurons were shorter in duration than corresponding EPSPs and consisted of both early and late components. Early EPSCs routinely increased in amplitude with hyperpolarization at all ages. In PN 3–5 neurons, the voltage dependence of late EPSCs was variable. By PN 6–8, late EPSCs always exhibited a region of reduced amplitude from -45 to -90 mV. The reversal potential for both early and late EPSCs was near +10 mV.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Neuroligin3 Splice Isoforms Shape Mouse Hippocampal Inhibitory Synaptic Function

2020 ◽  
Author(s):  
Motokazu Uchigashima ◽  
Ming Leung ◽  
Takuya Watanabe ◽  
Amy Cheung ◽  
Masahiko Watanabe ◽  
...  
Keyword(s):  
Synaptic Transmission ◽  
Molecular Mechanisms ◽  
Splice Variants ◽  
Autism Spectrum ◽  
Synaptic Function ◽  
Synaptic Activity ◽  
Sequencing Analysis ◽  
Dependent Manner ◽  
Splice Isoforms ◽  
Inhibitory Synaptic Transmission

ABSTRACTSynapse formation is a dynamic process essential for neuronal circuit development and maturation. At the synaptic cleft, trans-synaptic protein-protein interactions constitute major biological determinants of proper synapse efficacy. The balance of excitatory and inhibitory synaptic transmission (E-I balance) stabilizes synaptic activity. Dysregulation of the E-I balance has been implicated in neurodevelopmental disorders including autism spectrum disorders. However, the molecular mechanisms underlying E-I balance remain to be elucidated. Here, we investigate Neuroligin (Nlgn) genes that encode a family of postsynaptic adhesion molecules known to shape excitatory and inhibitory synaptic function. We demonstrate that Nlgn3 protein differentially regulates inhibitory synaptic transmission in a splice isoform-dependent manner at hippocampal CA1 synapses. Distinct subcellular localization patterns of Nlgn3 isoforms contribute to the functional differences observed among splice variants. Finally, single-cell sequencing analysis reveals that Nlgn1 and Nlgn3 are the major Nlgn genes and that expression of Nlgn splice isoforms are highly diverse in CA1 pyramidal neurons.

Tetanic Stimulation Induces Short-Term Potentiation of Inhibitory Synaptic Activity in the Rostral Nucleus of the Solitary Tract

1998 ◽  
Vol 79 (2) ◽  
pp. 595-604 ◽  
Author(s):  
Gintautas Grabauskas ◽  
Robert M. Bradley
Keyword(s):  
Time Constant ◽  
Decay Time ◽  
High Frequency ◽  
Synaptic Activity ◽  
Decay Time Constant ◽  
Tetanic Stimulation ◽  
Solitary Tract ◽  
Short Term ◽  
Term Potentiation ◽  
Rostral Nucleus

Grabauskas, Gintautas and Robert M. Bradley. Tetanic stimulation induces short-term potentiation of inhibitory synaptic activity in the rostral nucleus of the solitary tract. J. Neurophysiol. 79: 595–604, 1998. Whole cell recordings from neurons in the rostral nucleus of the solitary tract (rNST) were made to explore the effect of high-frequency tetanic stimulation on inhibitory postsynaptic potentials (IPSPs). IPSPs were elicited in the rNST by local electrical stimulation after pharmacological blockade of excitatory synaptic transmission. Tetanic stimulation at frequencies of 10–30 Hz resulted in sustained hyperpolarizing IPSPs that had a mean amplitude of −68 mV. The hyperpolarization resulted in a decrease in neuronal input resistance and was blocked by the γ-aminobutyric acid-A (GABAA) antagonist bicuculline. For most of the neurons ( n = 87/102), tetanic stimulation resulted in a maximum hyperpolarization immediately after initiation of the tetanic stimulation, but for some neurons the maximum was achieved after three or more consecutive shock stimuli in the tetanic train of stimuli. When the extracellular Ca2+ concentration was reduced, the maximum IPSP amplitude was reached after several consecutive shock stimuli in the tetanic train for all neurons. Tetanic stimulation at frequencies of 30 Hz and higher resulted in IPSPs that were not sustained but decayed to a more positive level of hyperpolarization. In some neurons the decay was sufficient to become depolarizing and resulted in a biphasic IPSP. It was possible to evoke this biphasic IPSP in all the neurons tested if the cells were hyperpolarized to −75 to −85 mV. The ionic mechanism of the depolarizing IPSPs was examined and was found to be due to an elevation of the extracellular K+ concentration and accumulation of intracellular Cl−. Tetanic stimulation increased the mean 80-ms decay time constant of a single shock–evoked IPSP up to 8 s. The length of the IPSP decay time constant was dependent on the duration and frequency of the tetanic stimulation as well as the extracellular Ca2+ concentration. Afferent sensory input to the rNST consists of trains of relatively high-frequency spike discharges similar to the tetanic stimulation frequencies used to elicit the IPSPs in the brain slices. Thus the short-term changes in inhibitory synaptic activity in the slice preparation probably occur in vivo and may play a key role in taste processing by facilitating synaptic integration.

scholarly journals Double-Dissociation of the Catecholaminergic Modulation of Synaptic Transmission in the Oval Bed Nucleus of the Stria Terminalis

2011 ◽  
Vol 105 (1) ◽  
pp. 145-153 ◽  
Author(s):  
Michal Krawczyk ◽  
François Georges ◽  
Robyn Sharma ◽  
Xenos Mason ◽  
Amandine Berthet ◽  
...  
Keyword(s):  
Synaptic Transmission ◽  
Drugs Of Abuse ◽  
Brain Slices ◽  
Stria Terminalis ◽  
Dependent Manner ◽  
Adult Rats ◽  
Bed Nucleus ◽  
Inhibitory Synaptic Transmission ◽  
Double Dissociation ◽  
Dose Dependent

The bed nucleus of the stria terminalis (BST) is a cluster of nuclei within the extended amygdala, a forebrain macrostructure with extensive projection to motor nuclei of the hindbrain. The subnuclei of the BST coordinate autonomic, neuroendocrine, and somato-motor functions and receive robust neuromodulatory monoaminergic afferents, including 5-HT-, noradrenaline (NA)-, and dopamine (DA)-containing terminals. In contrast to 5-HT and NA, little is known about how DA modulates neuronal activity or synaptic transmission in the BST. DA-containing afferents to the BST originate in the ventral tegmental area, the periaqueducal gray, and the retrorubral field. They form a fairly diffuse input to the dorsolateral BST with dense terminal fields in the oval (ovBST) and juxtacapsular (jxBST) nuclei. The efferent-afferent connectivity of the BST suggests that it may play a key role in motivated behaviors, consistent with recent evidence that the dorsolateral BST is a target for drugs of abuse. This study describes the effects of DA on synaptic transmission in the ovBST. Whole cell voltage clamp recordings were performed on ovBST neurons in brain slices from adult rats in the presence or absence of exogenous DA and receptor-targeted agonists and antagonists. The results showed that DA selectively and exclusively reduced inhibitory synaptic transmission in the ovBST in a dose-dependent and D2-like dopamine receptor-dependent manner. DA also modulated excitatory synaptic transmission in a dose-dependent dependent manner. However, this effect was mediated by α2-noradrenergic receptors. Thus these data reveal a double dissociation in catecholaminergic regulation of excitatory and inhibitory synaptic transmission in the ovBST and may shed light on the mechanisms involved in neuropathological behaviors such as stress-induced relapse to consumption of drugs of abuse.

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