1
|
Delta-opioid receptor-mediated modulation of excitability of individual hippocampal neurons: mechanisms involved. Pharmacol Rep 2020; 73:85-101. [PMID: 33161533 DOI: 10.1007/s43440-020-00183-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 10/22/2020] [Accepted: 10/24/2020] [Indexed: 12/11/2022]
Abstract
BACKGROUND Delta-opioid receptor (DOR)-mediated modulation of hippocampal neural networks is involved in emotions, cognition, and in pathophysiology and treatment of mood disorders. In this study, we examined the effects of DOR agonist (SNC80) and antagonist (naltrindole) on the excitability of individual hippocampal neurons. METHODS Primary neuronal cultures were prepared from hippocampi of newborn rats and cultivated in vitro for 8-14 days (DIV8-14). The effects of SNC80 naltrindole on evoked and spontaneous action potentials (APs) were measured at DIV8-9 and DIV13-14, respectively. RESULTS SNC80 (100 µM) potentiated spontaneous AP firing and stimulated sodium current; naltrindole had opposite effects. The stimulatory effect of 100 µM of SNC80 was revoked by pre-administration of 1 µM of naltrindole. SNC80 and naltrindole induced similar inhibitory effects on the evoked AP firing and on the calcium current. Further, SNC80 inhibited both peak and sustained potassium currents. Naltrindole had no effect on potassium currents. CONCLUSION We suggest that the effects of naltrindole and high concentration of SNC80 on the sodium currents are mediated via DORs and underlying the changes in spontaneous activity. The inhibitory effects of SNC80 on calcium and potassium currents might also be DOR-dependent; these currents might mediate SNC80 effect on the evoked AP firing. The inhibitory effects of naltrindole on calcium and of low doses of SNC80 on sodium currents might be however DOR independent. The behavioral effects of SNC80 and naltrindole, observed in previous studies, might be mediated, at least in part, via the modulatory effect of these ligands on the excitability of hippocampal neurons.
Collapse
|
2
|
Fernández-Fernández D, Lamas JA. Metabotropic Modulation of Potassium Channels During Synaptic Plasticity. Neuroscience 2020; 456:4-16. [PMID: 32114098 DOI: 10.1016/j.neuroscience.2020.02.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 02/14/2020] [Accepted: 02/18/2020] [Indexed: 01/06/2023]
Abstract
Besides their primary function mediating the repolarization phase of action potentials, potassium channels exquisitely and ubiquitously regulate the resting membrane potential of neurons and therefore have a key role establishing their intrinsic excitability. This group of proteins is composed of a very diverse collection of voltage-dependent and -independent ion channels, whose specific distribution is finely tuned at the level of the synapse. Both at the presynaptic and postsynaptic membranes, different types of potassium channels are subjected to modulation by second messenger signaling cascades triggered by metabotropic receptors, which in this way serve as a link between neurotransmitter actions and changes in the neuron membrane excitability. On the one hand, by regulating the resting membrane potential of the postsynaptic membrane, potassium channels appear to be critical towards setting the threshold for the induction of long-term potentiation and depression. On the other hand, these channels maintain the presynaptic membrane potential under control, therefore influencing the probability of neurotransmitter release underlying different forms of short-term plasticity. In the present review, we examine in detail the role of metabotropic receptors translating their activation by different neurotransmitters into a final effect modulating several types of potassium channels. Furthermore, we evaluate the consequences that this interplay has on the induction and maintenance of different forms of synaptic plasticity.
Collapse
Affiliation(s)
- D Fernández-Fernández
- Laboratory of Neuroscience, Biomedical Research Center (CINBIO), University of Vigo, Vigo, Galicia, Spain.
| | - J A Lamas
- Laboratory of Neuroscience, Biomedical Research Center (CINBIO), University of Vigo, Vigo, Galicia, Spain
| |
Collapse
|
3
|
Albiñana E, Luengo JG, Baraibar AM, Muñoz MD, Gandía L, Solís JM, Hernández-Guijo JM. Choline induces opposite changes in pyramidal neuron excitability and synaptic transmission through a nicotinic receptor-independent process in hippocampal slices. Pflugers Arch 2017; 469:779-795. [PMID: 28176016 DOI: 10.1007/s00424-017-1939-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 01/17/2017] [Accepted: 01/19/2017] [Indexed: 01/13/2023]
Abstract
Choline is present at cholinergic synapses as a product of acetylcholine degradation. In addition, it is considered a selective agonist for α5 and α7 nicotinic acetylcholine receptors (nAChRs). In this study, we determined how choline affects action potentials and excitatory synaptic transmission using extracellular and intracellular recording techniques in CA1 area of hippocampal slices obtained from both mice and rats. Choline caused a reversible depression of evoked field excitatory postsynaptic potentials (fEPSPs) in a concentration-dependent manner that was not affected by α7 nAChR antagonists. Moreover, this choline-induced effect was not mimicked by either selective agonists or allosteric modulators of α7 nAChRs. Additionally, this choline-mediated effect was not prevented by either selective antagonists of GABA receptors or hemicholinium, a choline uptake inhibitor. The paired pulse facilitation paradigm, which detects whether a substance affects presynaptic release of glutamate, was not modified by choline. On the other hand, choline induced a robust increase of population spike evoked by orthodromic stimulation but did not modify that evoked by antidromic stimulation. We also found that choline impaired recurrent inhibition recorded in the pyramidal cell layer through a mechanism independent of α7 nAChR activation. These choline-mediated effects on fEPSP and population spike observed in rat slices were completely reproduced in slices obtained from α7 nAChR knockout mice, which reinforces our conclusion that choline modulates synaptic transmission and neuronal excitability by a mechanism independent of nicotinic receptor activation.
Collapse
Affiliation(s)
- E Albiñana
- Department of Pharmacology and Therapeutic, University Autónoma de Madrid, Av. Arzobispo Morcillo 4, 28029, Madrid, Spain.,Instituto Teófilo Hernando, Facultad de Medicina, University Autónoma de Madrid, 28029, Madrid, Spain
| | - J G Luengo
- Department of Pharmacology and Therapeutic, University Autónoma de Madrid, Av. Arzobispo Morcillo 4, 28029, Madrid, Spain.,Instituto Teófilo Hernando, Facultad de Medicina, University Autónoma de Madrid, 28029, Madrid, Spain
| | - A M Baraibar
- Department of Pharmacology and Therapeutic, University Autónoma de Madrid, Av. Arzobispo Morcillo 4, 28029, Madrid, Spain.,Instituto Teófilo Hernando, Facultad de Medicina, University Autónoma de Madrid, 28029, Madrid, Spain
| | - M D Muñoz
- Servicio de Neurología Experimental, Hospital Universitario Ramón y Cajal, IRYCIS, 28034, Madrid, Spain
| | - L Gandía
- Department of Pharmacology and Therapeutic, University Autónoma de Madrid, Av. Arzobispo Morcillo 4, 28029, Madrid, Spain.,Instituto Teófilo Hernando, Facultad de Medicina, University Autónoma de Madrid, 28029, Madrid, Spain
| | - J M Solís
- Servicio de Neurobiología-Investigación, Hospital Universitario Ramón y Cajal, IRYCIS, 28034, Madrid, Spain
| | - J M Hernández-Guijo
- Department of Pharmacology and Therapeutic, University Autónoma de Madrid, Av. Arzobispo Morcillo 4, 28029, Madrid, Spain. .,Instituto Teófilo Hernando, Facultad de Medicina, University Autónoma de Madrid, 28029, Madrid, Spain.
| |
Collapse
|
4
|
Activation of endocannabinoid system in the rat basolateral amygdala improved scopolamine-induced memory consolidation impairment. Behav Brain Res 2016; 311:183-191. [DOI: 10.1016/j.bbr.2016.05.043] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 05/17/2016] [Accepted: 05/20/2016] [Indexed: 12/28/2022]
|
5
|
Ohi Y, Kato D, Mizuno M, Sato T, Ueki Y, Borlongan CV, Ojika K, Haji A, Matsukawa N. Enhancement of long-term potentiation via muscarinic modulation in the hippocampus of HCNP precursor transgenic mice. Neurosci Lett 2015; 597:1-6. [PMID: 25899776 DOI: 10.1016/j.neulet.2015.04.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 03/26/2015] [Accepted: 04/15/2015] [Indexed: 10/23/2022]
Abstract
Hippocampal cholinergic neurostimulating peptide (HCNP) regulates acetylcholine synthesis in the septal hippocampus through the quantitative increase of choline acetyltransferase levels in the septal nucleus both in vitro and in vivo. Additionally, HCNP-precursor protein transgenic (HCNP-pp Tg) mice display depressive behavior. To examine the physiological function of HCNP and/or HCNP-pp on hippocampal neural activity, we investigated whether overexpression of HCNP-pp strengthened the efficiency of neural activity in the hippocampus. Long-term potentiation (LTP) of excitatory synaptic transmission was induced by a tetanic stimulation of the Schaffer collateral-commissural fibers (SCs) in mouse hippocampal slices. LTP in HCNP-pp Tg mice was significantly enhanced when compared with wild-type littermate (WT) mice. This facilitation of LTP in HCNP-pp Tg mice was blocked by atropine or pirenzepine, but not by mecamylamine. In contrast, LTP in WT mice was not affected by atropine, but enhanced by carbachol. However, neither difference in the input-output relationship of field excitatory postsynaptic potentials nor in the facilitation ratio in paired-pulse stimulation of the SCs was observed between HCNP-pp Tg and WT mice, indicating that presynaptic glutamate release in HCNP-pp Tg mice is similar to that of WT mice. These results suggest that muscarinic (M1) modulation of glutamatergic postsynaptic function may be involved in strengthening LTP in HCNP-pp Tg mice.
Collapse
Affiliation(s)
- Yoshiaki Ohi
- Laboratory of Neuropharmacology, School of Pharmacy, Aichi Gakuin University, 1-100 Kusumoto, Chikusa-ku, Nagoya 464-8650, Japan
| | - Daisuke Kato
- Department of Neurology, School of Medicine, Nagoya City University, 1 Kawasumi, Mizuho-ku, Nagoya 467-8602, Japan
| | - Masayuki Mizuno
- Department of Neurology, School of Medicine, Nagoya City University, 1 Kawasumi, Mizuho-ku, Nagoya 467-8602, Japan
| | - Toyohiro Sato
- Department of Neurology, School of Medicine, Nagoya City University, 1 Kawasumi, Mizuho-ku, Nagoya 467-8602, Japan
| | - Yoshino Ueki
- Department of Neurology, School of Medicine, Nagoya City University, 1 Kawasumi, Mizuho-ku, Nagoya 467-8602, Japan
| | - Cesario V Borlongan
- Center of Excellence for Aging and Brain Repair, Department of Neurosurgery and Repair, University of South Florida, Tampa, Florida, USA
| | - Kosei Ojika
- Department of Neurology, School of Medicine, Nagoya City University, 1 Kawasumi, Mizuho-ku, Nagoya 467-8602, Japan
| | - Akira Haji
- Laboratory of Neuropharmacology, School of Pharmacy, Aichi Gakuin University, 1-100 Kusumoto, Chikusa-ku, Nagoya 464-8650, Japan
| | - Noriyuki Matsukawa
- Department of Neurology, School of Medicine, Nagoya City University, 1 Kawasumi, Mizuho-ku, Nagoya 467-8602, Japan.
| |
Collapse
|
6
|
Mans RA, Warmus BA, Smith CC, McMahon LL. An acetylcholinesterase inhibitor, eserine, induces long-term depression at CA3-CA1 synapses in the hippocampus of adult rats. J Neurophysiol 2014; 112:2388-97. [PMID: 25143547 DOI: 10.1152/jn.00048.2014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Studies in humans and rodents support a role for muscarinic ACh receptor (mAChR) and nicotinic AChR in learning and memory, and both regulate hippocampal synaptic plasticity using complex and often times opposing mechanisms. Acetylcholinesterase (AChE) inhibitors are commonly prescribed to enhance cholinergic signaling in Alzheimer's disease in hopes of rescuing cognitive function, caused, in part, by degeneration of cholinergic innervation to the hippocampus and cortex. Unfortunately, therapeutic efficacy is moderate and inconsistent, perhaps due to unanticipated mechanisms. M1 mAChRs bidirectionally control synaptic strength at CA3-CA1 synapses; weak pharmacological activation using carbachol (CCh) facilitates potentiation, whereas strong agonism induces muscarinic long-term depression (mLTD) via an ERK-dependent mechanism. Here, we tested the prediction that accumulation of extracellular ACh via inhibition of AChE is sufficient to induce LTD at CA3-CA1 synapses in hippocampal slices from adult rats. Although AChE inhibition with eserine induces LTD, it unexpectedly does not share properties with mLTD induced by CCh, as reported previously. Eserine-LTD was prevented by the M3 mAChR-preferring antagonist 1,1-dimethyl-4-diphenylacetoxypiperidinium iodide (4-DAMP), and pharmacological inhibition of MEK was completely ineffective. Additionally, pharmacological inhibition of p38 MAPK prevents mLTD but has no effect on eserine-LTD. Finally, long-term expression of eserine-LTD is partially dependent on a decrease in presynaptic release probability, likely caused by tonic activation of mAChRs by the sustained increase in extracellular ACh. Thus these findings extend current literature by showing that pharmacological AChE inhibition causes a prolonged decrease in presynaptic glutamate release at CA3-CA1 synapses, in addition to inducing a likely postsynaptic form of LTD.
Collapse
Affiliation(s)
- Robert Alan Mans
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama; Department of Physiology and Biophysics, University of Alabama at Birmingham, Birmingham, Alabama; and
| | - Brian A Warmus
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Caroline C Smith
- Department of Physiology and Biophysics, University of Alabama at Birmingham, Birmingham, Alabama; and
| | - Lori L McMahon
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama; Department of Physiology and Biophysics, University of Alabama at Birmingham, Birmingham, Alabama; and
| |
Collapse
|
7
|
Ionotropic glutamate receptors and voltage-gated Ca²⁺ channels in long-term potentiation of spinal dorsal horn synapses and pain hypersensitivity. Neural Plast 2013; 2013:654257. [PMID: 24224102 PMCID: PMC3808892 DOI: 10.1155/2013/654257] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Revised: 08/27/2013] [Accepted: 08/27/2013] [Indexed: 12/18/2022] Open
Abstract
Over the last twenty years of research on cellular mechanisms of pain hypersensitivity, long-term potentiation (LTP) of synaptic transmission in the spinal cord dorsal horn (DH) has emerged as an important contributor to pain pathology. Mechanisms that underlie LTP of spinal DH neurons include changes in the numbers, activity, and properties of ionotropic glutamate receptors (AMPA and NMDA receptors) and of voltage-gated Ca2+ channels. Here, we review the roles and mechanisms of these channels in the induction and expression of spinal DH LTP, and we present this within the framework of the anatomical organization and synaptic circuitry of the spinal DH. Moreover, we compare synaptic plasticity in the spinal DH with classical LTP described for hippocampal synapses.
Collapse
|