Self-sustained spreading depressions in the chicken retina and short-term neuronal-glial interactions within the gray matter neuropil

Lima, Vera Maura Fernandes de; Scheller, D.; Tegtmeier, F.; Hanke, Wolfgang; Schlue, Wolf-R.

doi:10.1016/0006-8993(93)91016-l

Cited by 23 publications

(14 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, this is the behaviour expected of any potassium‐selective membrane such as that in astrocytes. In fact, potassium and Δ V o signals during SD follow different time courses (Herreras & Somjen, 1993b) and may even be detached from each other (Fernandes de Lima et al ., 1993). Besides, the selective impairment of glial function and glial depolarization does not reduce SD negativity, but rather it becomes markedly prolonged (Largo et al ., 1996, 1997a,b).…”

Section: Discussionmentioning

confidence: 99%

Variations in tissue resistivity and in the extension of activated neuron domains shape the voltage signal during spreading depression in the CA1 in vivo

Makarova¹,

Gómez-Galán²,

Herreras³

2008

Eur J of Neuroscience

View full text Add to dashboard Cite

Spreading depression (SD), a wave of neuron activity related to migraine and the ischaemic penumbra, features a moving shell of extracellular negative potential shift (V(o)) whose generators are poorly understood. We investigated its subcellular correlates in the hippocampal CA1 in vivo by localizing the neuron domains that generate transmembrane current (I(m)) using field analysis, and the local changes of tissue resistivity, a major determinant of extracellular current flow. A large increase of tissue resistivity occurred in times and dendritic strata displaying large V(o), albeit with different rates. Typically, SD is composed of basal and apical dendritic components. The apical SD lasts much longer, while it becomes gradually restricted to a narrow dendritic region. Strikingly, pyramidal cells displayed a strong surge of inward current only when SD affected a small dendritic region. However, when the V(o) signal covered most of the main neuron axis, only smaller surges of inward current developed at the outer dendritic rims of a wide null current zone. Computational reconstruction showed that this effect was due to strong spatial cancellation of the inward and outward currents in SD-activated isopotential and shunted regions of individual neurons. Consequently, despite former accounts of large conductance increase, the net I(m) is small and the large DeltaV(o) amplitude mostly due to increased tissue resistivity. The particular subcellular evolution indicates an initial explosive opening of conductance along most of the pyramidal neuron followed by a wave-like centripetal closure towards the apical dendrites. The applicability of these mechanisms to SD in other brain regions is discussed.

show abstract

Section: Discussionmentioning

confidence: 99%

Variations in tissue resistivity and in the extension of activated neuron domains shape the voltage signal during spreading depression in the CA1 in vivo

Makarova¹,

Gómez-Galán²,

Herreras³

2008

Eur J of Neuroscience

View full text Add to dashboard Cite

show abstract

“…This stimulation produces a circular wave front in the retina propagating outwards isotropically with a speed of about 4.5 mm/min. In order to obtain spirals, the circular wave front is broken (at a diameter of ~1.5 mm) by local application of 0.5 ml Ringer solution through a pipette (tip diameter ~0.5 mm) containing a Mg 2+ concentration raised to 10 mM (Fernandes de Lima et al 1993). High Mg 2+ concentration, together with low Ca 2+ , is a classical neurophysiological manipulation to depress synaptic activity.…”

Section: Stimulation and Inhibitionmentioning

confidence: 99%

“…The potassium hypothesis was followed by a glutamate hypothesis (Van Harreveld 1959); subsequent hypotheses have mainly considered the role of the glial cells. The well-known slow negative potential change associated with this phenomenon has been found to be caused by the glial membrane potential (Fernandes de Lima et al 1993).…”

Section: Introductionmentioning

confidence: 99%

Self-induced splitting of spiral-shaped spreading depression waves in chicken retina

Dahlem

Müller

1997

Exp Brain Res

View full text Add to dashboard Cite

Spreading depression (SD) of electroencephalographic activity is a dynamic wave phenomenon in the central nervous system (CNS). The retina, especially the isolated chicken retina, is an excellent constituent of the CNS in which to observe the dynamic behavior of the SD wave fronts, because it changes its optical properties during a SD attack. The waves become visible as milky fronts on a black background. It is still controversial what the basic mechanistic steps of SD are, but certainly SD belongs to the self-organization phenomena occurring in neuronal tissue. In this work, spiral-shaped wave fronts are analyzed using digital video imaging techniques. We report how the inner end of the wave front, the spiral tip, breaks away repeatedly. This separation process is associated with a Z-shaped trajectory (extension approximately 1.2 mm) that is described by the tip over one spiral revolution (period 2.45+/-0.1 min). The Z-shaped trajectory does not remain fixed, but performs a complex motion across the retina with each period. This is the first time, to our knowledge, that established imaging methods have been applied to the study of the two-dimensional features of SD wave propagation and to obtaining quantitative data of their dynamics. Since these methods do not interfere with the tissue, it is possible to observe the intrinsic properties of the phenomenon without any external influence.

show abstract

“…It is well established that chemical waves, which affect the electrical activity of neurons, can propagate through out the cortex [17,18,19,20,21]. This brings to mind that such chemical waves can regulate the wiring process over the meso and macro scales.…”

Section: The Excitable Media Mechanismmentioning

confidence: 99%

From Neurons to Brain: Adaptive Self-Wiring of Neurons

Segev

Ben‐Jacob

1998

Advs. Complex Syst.

View full text Add to dashboard Cite

During embryonic morpho-genesis, a collection of individual neurons turns into a functioning network with unique capabilities. Only recently has this most staggering example of emergent process in the natural world, began to be studied. Here we propose a navigational strategy for neurites growth cones, based on sophisticated chemical signaling. We further propose that the embryonic environment (the neurons and the glia cells) acts as an excitable media in which concentric and spiral chemical waves are formed. Together with the navigation strategy, the chemical waves provide a mechanism for communication, regulation, and control required for the adaptive self-wiring of neurons.

show abstract

Self-sustained spreading depressions in the chicken retina and short-term neuronal-glial interactions within the gray matter neuropil

Cited by 23 publications

References 28 publications

Variations in tissue resistivity and in the extension of activated neuron domains shape the voltage signal during spreading depression in the CA1 in vivo

Variations in tissue resistivity and in the extension of activated neuron domains shape the voltage signal during spreading depression in the CA1 in vivo

Self-induced splitting of spiral-shaped spreading depression waves in chicken retina

From Neurons to Brain: Adaptive Self-Wiring of Neurons

Contact Info

Product

Resources

About