scholarly journals GluN2B-containing NMDA receptors and AMPA receptors in medial prefrontal cortex are necessary for odor span in rats

2013 ◽  
Vol 7 ◽  
Author(s):  
Don A. Davies ◽  
Quentin Greba ◽  
John G. Howland
Keyword(s):  
Prefrontal Cortex ◽  
Nmda Receptors ◽  
Medial Prefrontal Cortex ◽  
Ampa Receptors ◽  
Odor Span

scholarly journals Metaplastic Effects of Ketamine and MK-801 on Glutamate Receptors Expression in Rat Medial Prefrontal Cortex and Hippocampus

2021 ◽  
Author(s):  
Alessandro Piva ◽  
Lucia Caffino ◽  
Francesca Mottarlini ◽  
Nicholas Pintori ◽  
Fernando Castillo Díaz ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Nmda Receptors ◽  
Glutamate Receptors ◽  
Medial Prefrontal Cortex ◽  
Ampa Receptors ◽  
Glutamate Transporter ◽  
Fine Tuning ◽  
Scaffolding Proteins ◽  
Glutamatergic Synapses ◽  
Mk 801

AbstractKetamine and MK-801 by blocking NMDA receptors may induce reinforcing effects as well as schizophrenia-like symptoms. Recent results showed that ketamine can also effectively reverse depressive signs in patients’ refractory to standard therapies. This evidence clearly points to the need of characterization of effects of these NMDARs antagonists on relevant brain areas for mood disorders. The aim of the present study was to investigate the molecular changes occurring at glutamatergic synapses 24 h after ketamine or MK-801 treatment in the rat medial prefrontal cortex (mPFC) and hippocampus (Hipp). In particular, we analyzed the levels of the glutamate transporter-1 (GLT-1), NMDA receptors, AMPA receptors subunits, and related scaffolding proteins. In the homogenate, we found a general decrease of protein levels, whereas their changes in the post-synaptic density were more complex. In fact, ketamine in the mPFC decreased the level of GLT-1 and increased the level of GluN2B, GluA1, GluA2, and scaffolding proteins, likely indicating a pattern of enhanced excitability. On the other hand, MK-801 only induced sparse changes with apparently no correlation to functional modification. Differently from mPFC, in Hipp, both substances reduced or caused no changes of glutamate receptors and scaffolding proteins expression. Ketamine decreased NMDA receptors while increased AMPA receptors subunit ratios, an effect indicative of permissive metaplastic modulation; conversely, MK-801 only decreased the latter, possibly representing a blockade of further synaptic plasticity. Taken together, these findings indicate a fine tuning of glutamatergic synapses by ketamine compared to MK-801 both in the mPFC and Hipp.

scholarly journals Interactions between medial prefrontal cortex and dorsomedial striatum are necessary for odor span capacity in rats: role of GluN2B-containing NMDA receptors

2017 ◽  
Vol 24 (10) ◽  
pp. 524-531 ◽  
Author(s):  
Don A. Davies ◽  
Quentin Greba ◽  
Jantz C. Selk ◽  
Jillian K. Catton ◽  
Landon D. Baillie ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Nmda Receptors ◽  
Medial Prefrontal Cortex ◽  
Odor Span ◽  
Dorsomedial Striatum

Interaction of Dopamine D1 and NMDA Receptors Mediates Acute Clozapine Potentiation of Glutamate EPSPs in Rat Prefrontal Cortex

2002 ◽  
Vol 87 (5) ◽  
pp. 2324-2336 ◽  
Author(s):  
Long Chen ◽  
Charles R. Yang
Keyword(s):  
Prefrontal Cortex ◽  
Nmda Receptor ◽  
Nmda Receptors ◽  
Receptor Antagonist ◽  
Ampa Receptors ◽  
Nmda Receptor Antagonist ◽  
D1 Receptor ◽  
Resting Membrane Potential ◽  
Cellular Mechanisms ◽  
Cognitive Improvement

The atypical antipsychotic drug clozapine effectively alleviates both negative and positive symptoms of schizophrenia via unclear cellular mechanisms. Clozapine may modulate both glutamatergic and dopaminergic transmission in the prefrontal cortex (PFC) to achieve part of its therapeutic actions. Using whole cell patch-clamp techniques, current-clamp recordings in layers V–VI pyramidal neurons from rat PFC slices showed that stimulation of local afferents (in 2 μM bicuculline) evoked mixed [AMPA/kainate and N-methyl-d-aspartate (NMDA) receptors] glutamate receptor-mediated excitatory postsynaptic potentials (EPSPs). Clozapine (1 μM) potentiated polysynaptically mediated evoked EPSPs ( V Hold = −65 mV), or reversed EPSPs (rEPSP, V Hold = +20 mV) for >30 min. The potentiated EPSPs or rEPSPs were attenuated by elevating [Ca2+]O(7 mM), by application of NMDA receptor antagonist 2-amino5-phosphonovaleric acid (50 μM), or by pretreatment with dopamine D1/D5 receptor antagonist SCH23390 (1 μM) but could be further enhanced by a dopamine reuptake inhibitor bupropion (1 μM). Clozapine had no significant effect on pharmacologically isolated evoked NMDA-rEPSP or AMPA-rEPSPs but increased spontaneous EPSPs without changing the steady-state resting membrane potential. Under voltage clamp, clozapine (1 μM) enhanced the frequency, and the number of low-amplitude (5–10 pA) AMPA receptor-mediated spontaneous EPSCs, while there was no such changes with the mini-EPSCs (in 1 μM TTX). Taken together these data suggest that acute clozapine can increase spike-dependent presynaptic release of glutamate and dopamine. The glutamate stimulates distal dendritic AMPA receptors to increase spontaneous EPSCs and enabled a voltage-dependent activation of neuronal NMDA receptors. The dopamine released stimulates postsynaptic D1 receptor to modulate a lasting potentiation of the NMDA receptor component of the glutamatergic synaptic responses in the PFC neuronal network. This sequence of early synaptic events induced by acute clozapine may comprise part of the activity that leads to later cognitive improvement in schizophrenia.

scholarly journals Early-life blockade of NMDA receptors induces epigenetic abnormalities in the adult medial prefrontal cortex: possible involvement in memory impairment in trace fear conditioning

2019 ◽  
Vol 237 (1) ◽  
pp. 231-248 ◽  
Author(s):  
Joachim Latusz ◽  
Marzena Maćkowiak
Keyword(s):  
Prefrontal Cortex ◽  
Nmda Receptors ◽  
Fear Conditioning ◽  
Medial Prefrontal Cortex ◽  
Memory Retrieval ◽  
Early Life ◽  
Histone H3 ◽  
Protein Levels ◽  
Trace Fear Conditioning ◽  
Trace Fear

Abstract Rationale Several findings indicate that early-life dysfunction of N-methyl-d-aspartate (NMDA) receptors might cause schizophrenia-like abnormalities in adulthood that might be induced by impairments in epigenetic regulation. Objectives In the present study, we investigated whether postnatal blockade of NMDA receptors (within the first 3 weeks of life) by the competitive antagonist CGP 37849 (CGP) might affect some epigenetic markers in the adult medial prefrontal cortex (mPFC). Methods Histone H3 phosphorylation at serine 10 (H3S10ph), histone H3 acetylation at lysine 9 or 14 (H3K9ac or H3K14ac, respectively), or expression of histone deacetylase (HDAC) 2, HDAC5, myocyte enhancer factor (MEF) 2D and activity-regulated cytoskeleton-associated protein (Arc) were analysed. Moreover, we also evaluated whether the deacetylase inhibitor sodium butyrate (SB; 1.2 mg/kg, ip) could prevent behavioural and neurochemical changes in the mPFC induced by CGP during memory retrieval in the trace fear conditioning paradigm. Results The results showed that CGP administration increased the number of H3S10ph nuclei but did not affect H3K9ac and H3K14ac or HDAC2 protein levels. However, CGP administration altered the HDAC5 mRNA and protein levels and increased the mRNA and protein levels of MEF2D. CGP also increased Arc mRNA, which was correlated with an increase in the amount of Arc DNA bound to MEF2D. SB given 2 h after training prevented impairment of the freezing response and disruption of epigenetic markers (H3S10ph, HDAC5, MEF2D) and Arc expression during memory retrieval induced by CGP administration. Conclusions The early-life blockade of NMDA receptors impairs some epigenetic regulatory processes in the mPFC that are involved in fear memory formation.

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