Rod bipolar cells and horizontal cells form displaced synaptic contacts with rods in the outer nuclear layer of the nob2 retina

Philippa R. Bayley, Catherine Morgans

    Research output: Contribution to journalArticle

    61 Citations (Scopus)

    Abstract

    The nob2 mouse carries a null mutation in the Cacna1f gene, which encodes the pore-forming subunit of the L-type calcium channel, Cav1.4. The loss of the electroretinogram b-wave in these mice suggests a severe reduction in transmission between photoreceptors and second-order neurons in the retina and supports a central role for the Cav1.4 calcium channel at photoreceptor ribbon synapses, to which it has been localized. Here we show that the loss of Cav1.4 leads to the aberrant outgrowth of rod bipolar cell dendrites and horizontal cell processes into the outer nuclear layer (ONL) of the nob2 retina and to the formation of ectopic synaptic contacts with rod photoreceptors in the ONL. Ectopic contacts are predominantly between rods and rod bipolar cells, with horizontal cell processes also present at some sites. Ectopic contacts contain apposed pre- and postsynaptic specializations, albeit with malformed synaptic ribbons. Cone photoreceptor terminals do not participate in ectopic contacts in the ONL. During retinal development, ectopic contacts appear in the days after eye opening, appearing progressively farther into the ONL at later postnatal stages. Ectopic contacts develop at the tips of rod bipolar cell dendrites and are less frequently associated with the tips of horizontal cell processes, consistent with the adult phenotype. The relative occurrence of pre- and postsynaptic markers in the ONL during development suggests a mechanism for the formation of ectopic synaptic contacts that is driven by the retraction of rod photoreceptor terminals and neurite outgrowth by rod bipolar cell dendrites.

    Original languageEnglish (US)
    Pages (from-to)286-298
    Number of pages13
    JournalJournal of Comparative Neurology
    Volume500
    Issue number2
    DOIs
    StatePublished - Jan 10 2007

    Fingerprint

    Retina
    Dendrites
    Retinal Rod Photoreceptor Cells
    Retinal Cone Photoreceptor Cells
    L-Type Calcium Channels
    Calcium Channels
    Synapses
    Phenotype
    Neurons
    Mutation
    Genes

    Keywords

    • Bipolar cell
    • Horizontal cell
    • Rod retraction
    • Second-order neuron outgrowth

    ASJC Scopus subject areas

    • Neuroscience(all)

    Cite this

    Rod bipolar cells and horizontal cells form displaced synaptic contacts with rods in the outer nuclear layer of the nob2 retina. / Bayley, Philippa R.; Morgans, Catherine.

    In: Journal of Comparative Neurology, Vol. 500, No. 2, 10.01.2007, p. 286-298.

    Research output: Contribution to journalArticle

    @article{e1f4795913a44e88beb0d334aff92bf4,
    title = "Rod bipolar cells and horizontal cells form displaced synaptic contacts with rods in the outer nuclear layer of the nob2 retina",
    abstract = "The nob2 mouse carries a null mutation in the Cacna1f gene, which encodes the pore-forming subunit of the L-type calcium channel, Cav1.4. The loss of the electroretinogram b-wave in these mice suggests a severe reduction in transmission between photoreceptors and second-order neurons in the retina and supports a central role for the Cav1.4 calcium channel at photoreceptor ribbon synapses, to which it has been localized. Here we show that the loss of Cav1.4 leads to the aberrant outgrowth of rod bipolar cell dendrites and horizontal cell processes into the outer nuclear layer (ONL) of the nob2 retina and to the formation of ectopic synaptic contacts with rod photoreceptors in the ONL. Ectopic contacts are predominantly between rods and rod bipolar cells, with horizontal cell processes also present at some sites. Ectopic contacts contain apposed pre- and postsynaptic specializations, albeit with malformed synaptic ribbons. Cone photoreceptor terminals do not participate in ectopic contacts in the ONL. During retinal development, ectopic contacts appear in the days after eye opening, appearing progressively farther into the ONL at later postnatal stages. Ectopic contacts develop at the tips of rod bipolar cell dendrites and are less frequently associated with the tips of horizontal cell processes, consistent with the adult phenotype. The relative occurrence of pre- and postsynaptic markers in the ONL during development suggests a mechanism for the formation of ectopic synaptic contacts that is driven by the retraction of rod photoreceptor terminals and neurite outgrowth by rod bipolar cell dendrites.",
    keywords = "Bipolar cell, Horizontal cell, Rod retraction, Second-order neuron outgrowth",
    author = "Bayley, {Philippa R.} and Catherine Morgans",
    year = "2007",
    month = "1",
    day = "10",
    doi = "10.1002/cne.21188",
    language = "English (US)",
    volume = "500",
    pages = "286--298",
    journal = "Journal of Comparative Neurology",
    issn = "0021-9967",
    publisher = "Wiley-Liss Inc.",
    number = "2",

    }

    TY - JOUR

    T1 - Rod bipolar cells and horizontal cells form displaced synaptic contacts with rods in the outer nuclear layer of the nob2 retina

    AU - Bayley, Philippa R.

    AU - Morgans, Catherine

    PY - 2007/1/10

    Y1 - 2007/1/10

    N2 - The nob2 mouse carries a null mutation in the Cacna1f gene, which encodes the pore-forming subunit of the L-type calcium channel, Cav1.4. The loss of the electroretinogram b-wave in these mice suggests a severe reduction in transmission between photoreceptors and second-order neurons in the retina and supports a central role for the Cav1.4 calcium channel at photoreceptor ribbon synapses, to which it has been localized. Here we show that the loss of Cav1.4 leads to the aberrant outgrowth of rod bipolar cell dendrites and horizontal cell processes into the outer nuclear layer (ONL) of the nob2 retina and to the formation of ectopic synaptic contacts with rod photoreceptors in the ONL. Ectopic contacts are predominantly between rods and rod bipolar cells, with horizontal cell processes also present at some sites. Ectopic contacts contain apposed pre- and postsynaptic specializations, albeit with malformed synaptic ribbons. Cone photoreceptor terminals do not participate in ectopic contacts in the ONL. During retinal development, ectopic contacts appear in the days after eye opening, appearing progressively farther into the ONL at later postnatal stages. Ectopic contacts develop at the tips of rod bipolar cell dendrites and are less frequently associated with the tips of horizontal cell processes, consistent with the adult phenotype. The relative occurrence of pre- and postsynaptic markers in the ONL during development suggests a mechanism for the formation of ectopic synaptic contacts that is driven by the retraction of rod photoreceptor terminals and neurite outgrowth by rod bipolar cell dendrites.

    AB - The nob2 mouse carries a null mutation in the Cacna1f gene, which encodes the pore-forming subunit of the L-type calcium channel, Cav1.4. The loss of the electroretinogram b-wave in these mice suggests a severe reduction in transmission between photoreceptors and second-order neurons in the retina and supports a central role for the Cav1.4 calcium channel at photoreceptor ribbon synapses, to which it has been localized. Here we show that the loss of Cav1.4 leads to the aberrant outgrowth of rod bipolar cell dendrites and horizontal cell processes into the outer nuclear layer (ONL) of the nob2 retina and to the formation of ectopic synaptic contacts with rod photoreceptors in the ONL. Ectopic contacts are predominantly between rods and rod bipolar cells, with horizontal cell processes also present at some sites. Ectopic contacts contain apposed pre- and postsynaptic specializations, albeit with malformed synaptic ribbons. Cone photoreceptor terminals do not participate in ectopic contacts in the ONL. During retinal development, ectopic contacts appear in the days after eye opening, appearing progressively farther into the ONL at later postnatal stages. Ectopic contacts develop at the tips of rod bipolar cell dendrites and are less frequently associated with the tips of horizontal cell processes, consistent with the adult phenotype. The relative occurrence of pre- and postsynaptic markers in the ONL during development suggests a mechanism for the formation of ectopic synaptic contacts that is driven by the retraction of rod photoreceptor terminals and neurite outgrowth by rod bipolar cell dendrites.

    KW - Bipolar cell

    KW - Horizontal cell

    KW - Rod retraction

    KW - Second-order neuron outgrowth

    UR - http://www.scopus.com/inward/record.url?scp=33845564840&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=33845564840&partnerID=8YFLogxK

    U2 - 10.1002/cne.21188

    DO - 10.1002/cne.21188

    M3 - Article

    C2 - 17111373

    AN - SCOPUS:33845564840

    VL - 500

    SP - 286

    EP - 298

    JO - Journal of Comparative Neurology

    JF - Journal of Comparative Neurology

    SN - 0021-9967

    IS - 2

    ER -