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Ethanol modulates spontaneous calcium waves in axonal growth cones in vitro.

Lindsley TA, Mazurkiewicz JE - Brain Sci (2013)

Bottom Line: Using time-series fluorescence calcium imaging we found that acute treatment of fetal rat hippocampal neurons with 43 or 87 mM ethanol at an early stage of development in culture decreased the percent of axon growth cones showing at least one Ca2+ wave during 10 min of recording, from 18% in controls to 5% in cultures exposed to ethanol.As expected, waves were most prevalent in stationary or retracting growth cones in all treatment groups, except in cultures exposed chronically to 87 mM ethanol.Thus, the relationship between growth cone Ca2+ waves and axon growth dynamics is disrupted by ethanol.

View Article: PubMed Central - PubMed

Affiliation: Center for Neuropharmacology & Neuroscience, Albany Medical College (MC-136), 47 New Scotland Ave., Albany, NY 12208, USA. lindslt@mail.amc.edu.

ABSTRACT
In developing neurons the frequency of long duration, spontaneous, transient calcium (Ca2+) elevations localized to the growth cone, is inversely related to the rate of axon elongation and increases several fold when axons pause. Here we report that these spontaneous Ca2+ transients with slow kinetics, called Ca2+ waves, are modulated by conditions of ethanol exposure that alter axonal growth dynamics. Using time-series fluorescence calcium imaging we found that acute treatment of fetal rat hippocampal neurons with 43 or 87 mM ethanol at an early stage of development in culture decreased the percent of axon growth cones showing at least one Ca2+ wave during 10 min of recording, from 18% in controls to 5% in cultures exposed to ethanol. Chronic exposure to 43 mM ethanol also reduced the incidence of Ca2+ waves to 8%, but exposure to 87 mM ethanol increased their incidence to 31%. Neither chronic nor acute ethanol affected the peak amplitude, time to peak or total duration of Ca2+ waves. In some experiments, we determined the temporal correlation between Ca2+ waves and growth and non-growth phases of axonal growth dynamics. As expected, waves were most prevalent in stationary or retracting growth cones in all treatment groups, except in cultures exposed chronically to 87 mM ethanol. Thus, the relationship between growth cone Ca2+ waves and axon growth dynamics is disrupted by ethanol.

No MeSH data available.


Related in: MedlinePlus

Morphology of hippocampal pyramidal neurons at an early stage of development in low-density dissociated cultures. Shown is a phase contrast image of a representative embryonic rat hippocampal pyramidal neuron 1-day after plating. It illustrates the typical appearance of the newly formed axon, tipped by a growth cone. Several shorter processes emerging from the cell body are nascent dendrites.
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brainsci-03-00615-f001: Morphology of hippocampal pyramidal neurons at an early stage of development in low-density dissociated cultures. Shown is a phase contrast image of a representative embryonic rat hippocampal pyramidal neuron 1-day after plating. It illustrates the typical appearance of the newly formed axon, tipped by a growth cone. Several shorter processes emerging from the cell body are nascent dendrites.

Mentions: To determine whether Ca2+ waves occur in dissociated hippocampal neurons, we loaded fetal rat hippocampal neurons with the Ca2+ indicator dye Fluo-3 and imaged their axonal growth cones for 10 min. Imaging was performed on cultures 24 h after plating, when axons are rapidly extending but not intermingled with other processes. Only pyramidal neurons, which make up greater than 90% of the cells in these cultures, were imaged. Axons were identified by their length, which had to be longer than 40 µm and also longer than the next longest process by at least 20 µm [18] (Figure 1).


Ethanol modulates spontaneous calcium waves in axonal growth cones in vitro.

Lindsley TA, Mazurkiewicz JE - Brain Sci (2013)

Morphology of hippocampal pyramidal neurons at an early stage of development in low-density dissociated cultures. Shown is a phase contrast image of a representative embryonic rat hippocampal pyramidal neuron 1-day after plating. It illustrates the typical appearance of the newly formed axon, tipped by a growth cone. Several shorter processes emerging from the cell body are nascent dendrites.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4061854&req=5

brainsci-03-00615-f001: Morphology of hippocampal pyramidal neurons at an early stage of development in low-density dissociated cultures. Shown is a phase contrast image of a representative embryonic rat hippocampal pyramidal neuron 1-day after plating. It illustrates the typical appearance of the newly formed axon, tipped by a growth cone. Several shorter processes emerging from the cell body are nascent dendrites.
Mentions: To determine whether Ca2+ waves occur in dissociated hippocampal neurons, we loaded fetal rat hippocampal neurons with the Ca2+ indicator dye Fluo-3 and imaged their axonal growth cones for 10 min. Imaging was performed on cultures 24 h after plating, when axons are rapidly extending but not intermingled with other processes. Only pyramidal neurons, which make up greater than 90% of the cells in these cultures, were imaged. Axons were identified by their length, which had to be longer than 40 µm and also longer than the next longest process by at least 20 µm [18] (Figure 1).

Bottom Line: Using time-series fluorescence calcium imaging we found that acute treatment of fetal rat hippocampal neurons with 43 or 87 mM ethanol at an early stage of development in culture decreased the percent of axon growth cones showing at least one Ca2+ wave during 10 min of recording, from 18% in controls to 5% in cultures exposed to ethanol.As expected, waves were most prevalent in stationary or retracting growth cones in all treatment groups, except in cultures exposed chronically to 87 mM ethanol.Thus, the relationship between growth cone Ca2+ waves and axon growth dynamics is disrupted by ethanol.

View Article: PubMed Central - PubMed

Affiliation: Center for Neuropharmacology & Neuroscience, Albany Medical College (MC-136), 47 New Scotland Ave., Albany, NY 12208, USA. lindslt@mail.amc.edu.

ABSTRACT
In developing neurons the frequency of long duration, spontaneous, transient calcium (Ca2+) elevations localized to the growth cone, is inversely related to the rate of axon elongation and increases several fold when axons pause. Here we report that these spontaneous Ca2+ transients with slow kinetics, called Ca2+ waves, are modulated by conditions of ethanol exposure that alter axonal growth dynamics. Using time-series fluorescence calcium imaging we found that acute treatment of fetal rat hippocampal neurons with 43 or 87 mM ethanol at an early stage of development in culture decreased the percent of axon growth cones showing at least one Ca2+ wave during 10 min of recording, from 18% in controls to 5% in cultures exposed to ethanol. Chronic exposure to 43 mM ethanol also reduced the incidence of Ca2+ waves to 8%, but exposure to 87 mM ethanol increased their incidence to 31%. Neither chronic nor acute ethanol affected the peak amplitude, time to peak or total duration of Ca2+ waves. In some experiments, we determined the temporal correlation between Ca2+ waves and growth and non-growth phases of axonal growth dynamics. As expected, waves were most prevalent in stationary or retracting growth cones in all treatment groups, except in cultures exposed chronically to 87 mM ethanol. Thus, the relationship between growth cone Ca2+ waves and axon growth dynamics is disrupted by ethanol.

No MeSH data available.


Related in: MedlinePlus