Comparison of three intracellular markers for combined electrophysiological, morphological and immunohistochemical analyses

Tasker, Jeffrey G.; Hoffman, Neil W.; Dudek, F. Edward

doi:10.1016/0165-0270(91)90163-t

Cited by 26 publications

(20 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Tasker et al . [7] compared LY, the fluorescent dye ethidium bromide and biocytin for intracellular recordings and staining in hypothalamic neurons. They concluded, that overall, the electrical recordings with biocytin were the best.…”

Section: Electrophysiological Studies Using Ly‐filled Electrodesmentioning

confidence: 99%

Lucifer yellow – an angel rather than the devil

Hanani

2011

J Cellular Molecular Medi

View full text Add to dashboard Cite

The fluorescent dye Lucifer yellow (LY) was introduced in 1978, and has been extremely useful in studying cell structure and communications. This dye has been used mostly for labelling cells by intracellular injection from microelectrodes. This review describes the numerous applications of LY, with emphasis on the enteric nervous system and interstitial cells of Cajal. Of particular importance is the dye coupling method, which enables the detection of cell coupling by gap junctions.

show abstract

Section: Electrophysiological Studies Using Ly‐filled Electrodesmentioning

confidence: 99%

Lucifer yellow – an angel rather than the devil

Hanani

2011

J Cellular Molecular Medi

View full text Add to dashboard Cite

show abstract

“…All experiments were done on MCNs voltage-clamped at Ϫ80 mV using an Axopatch 1D or Axopatch 200A amplifier and pClamp 7 software (Axon Instruments, Foster City, CA). MCNs were identified on the basis of the delayed onset to action potential generation in response to positive current injection (Tasker et al, 1991;Armstrong, 1995). Membrane currents were recorded without series resistance compensation, filtered at 1 kHz, digitized at 5-10 kHz, and stored for off-line analysis.…”

Section: Methodsmentioning

confidence: 99%

“…MCNs can be distinguished from other neurons by their characteristic delayed onset of action potential firing to depolarization from hyperpolarized potentials (Tasker et al, 1991;Armstrong, 1995). In addition, two subtypes of MCNs, namely AVP and OXT neurons, have been characterized by a number of electrophysiological features, including SOR (Armstrong et al, 1994;Stern and Armstrong, 1995).…”

Section: Voltage-dependent Currents Characterize Two Distinct Populatmentioning

confidence: 99%

Vasopressin Differentially Modulates Non-NMDA Receptors in Vasopressin and Oxytocin Neurons in the Supraoptic Nucleus

et al. 2003

View full text Add to dashboard Cite

Magnocellular neurons of the supraoptic nucleus release the neuropeptides oxytocin and vasopressin from their dendrites to regulate their synaptic inputs. This study aims to determine the cellular mechanism by which vasopressin modulates excitatory synaptic transmission. Presumably by electroporation through perforated patch, we were able to successfully introduce biocytin into cells in which we performed an electrophysiological study. This method enabled us to determine that roughly half of the recorded neurons were immunoreactive to oxytocin-associated neurophysin and showed two characteristic features: an inward rectification and a sustained outward rectification. The remaining half showed a linear voltage-current relationship and was immunoreactive to vasopressin-associated neurophysin. Using these electrophysiological characteristics and post hoc immunohistochemistry to identify vasopressin or oxytocin neurons, we found that vasopressin decreased evoked EPSCs in vasopressin neurons while increasing EPSCs in oxytocin neurons. In both types of neurons, EPSC decay constants were not affected, indicating that desensitization of non-NMDA receptors did not underlie the EPSC amplitude change. In vasopressin neurons, both vasopressin and a V1a receptor agonist, F-180, decreased AMPA-induced currents, an effect blocked by a V1a receptor antagonist SR49059. In oxytocin neurons, AMPA-induced currents were facilitated by vasopressin, whereas F-180 had no effect. An oxytocin receptor antagonist blocked the facilitatory effect of vasopressin. Thus, we conclude that vasopressin inhibits EPSCs in vasopressin neurons via postsynaptic V1a receptors, whereas it facilitates EPSCs in oxytocin neurons through oxytocin receptors.

show abstract

“…All experiments were performed on magnocellular neurons (MCNs) in the supraoptic nucleus (SON), voltage clamped at Ϫ80 mV by using an Axopatch 1D amplifier (Axon Instruments, Foster City, CA). MCNs were identified based on the delayed onset to action potential generation in response to positive current injection (9,10). Membrane currents were recorded without series resistance compensation, filtered at 1 kHz, and digitized at 2-10 kHz and stored for off-line analysis.…”

Section: Methodsmentioning

confidence: 99%

Nifedipine facilitates neurotransmitter release independently of calcium channels

Hirasawa

Pittman²

2003

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Nifedipine, a drug used for treatment of hypertension and angina, exerts its effect by calcium channel blockade and nitric oxide production. We report here a previously uncharacterized action of nifedipine on central synaptic transmission that may partially explain its side effects. Nifedipine causes a long-lasting facilitation of tetrodotoxin-insensitive spontaneous glutamate release. This effect is independent of its L-type calcium channel blocking effect, and is not mimicked by other dihydropyridines such as nimodipine, nicardipine, or Bay K 8644. The effect was dose dependent, with EC 50 of 7.8 M, with the lowest effective dose being 100 nM, a clinically relevant dose. At 10 M, the increase is 14.7-fold. This effect is largely calcium-independent, because Cd 2؉ , thapsigargin, or BAPTA-AM [1,2-bis(2-aminophenoxy)ethane-N,N,N,N-tetraacetic acid-acetoxymethyl ester] did not inhibit the nifedipine effect. Thus, nifedipine seems to act on the release process downstream of calcium entry or release. Protein kinases A or C do not mediate its effect, because it is not blocked by inhibitors of these kinases. Our finding indicates that nifedipine may be a useful tool as a secretagogue to directly target the release process, but raises caution for its use as an L-type calcium channel blocker. N ifedipine has been a commonly prescribed compound for treatment of angina and hypertension. Its clinical effect is attributed to its blocking action on L-type calcium channels or release of nitric oxide (NO) from the vascular endothelium, which will result in relaxation or prevention of cardiac or vascular smooth muscle contraction. Compared with other dihydropyridines (DHPs), nifedipine has been reported to have relatively high incidence of neurologic adverse reactions, such as dizziness (4.1-27%) and nervousness (Ͼ7.0%) (information obtained from www.drugdigest.org͞DD͞SE͞DisplayDrug͞1,3997,488,00. html?DVHNameϭNifedipine). Nifedipine can easily cross the brain-blood barrier (1); thus, it may have a direct effect in the brain. The present report introduces a previously uncharacterized action of nifedipine on synaptic transmission in the central nervous system. Nifedipine induces a profound increase in spontaneous glutamate release in a calcium-independent manner. This effect was unique to nifedipine and could not be mimicked by other DHPs; thus, its action is not through blockade of L-type calcium channels. Such synaptic activation in the central nervous system may underlie some of its adverse neurologic reactions.Spontaneous, action potential-independent transmitter release occurs when a synaptic vesicle fuses spontaneously to the presynaptic plasma membrane and releases its content. It is not yet clear what may be the role of spontaneous release for the function of the nervous system. Recent studies indicate that spontaneously released glutamate acts to maintain the postsynaptic dendritic structure (2) and to induce clustering of AMPA (␣-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) receptors on the postsynaptic membran...

show abstract

Comparison of three intracellular markers for combined electrophysiological, morphological and immunohistochemical analyses

Cited by 26 publications

References 25 publications

Lucifer yellow – an angel rather than the devil

Lucifer yellow – an angel rather than the devil

Vasopressin Differentially Modulates Non-NMDA Receptors in Vasopressin and Oxytocin Neurons in the Supraoptic Nucleus

Nifedipine facilitates neurotransmitter release independently of calcium channels

Contact Info

Product

Resources

About