Martin P. Meyer

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The form of a neuron's dendritic arbor determines the set of axons with which it may form synaptic contacts, thus establishing connectivity within neural circuits. However, the dynamic relationship between dendrite growth and synaptogenesis is not well understood. To observe both processes simultaneously, we performed long-term imaging of non-spiny(More)
To explore the relationship between axon arbor growth and synaptogenesis, developing retinal ganglion cell (RGC) axon arbors in zebrafish optic tectum were imaged in vivo at high temporal and spatial resolution using two-photon microscopy. Individual RGC axons were dually labeled by expression of a cytosolic red fluorescent protein (DsRed Express) to mark(More)
In the retinotectal projection, synapses guide retinal ganglion cell (RGC) axon arbor growth by promoting branch formation and by selectively stabilizing branches. To ask whether presynaptic function is required for this dual role of synapses, we have suppressed presynaptic function in single RGCs using targeted expression of tetanus toxin light-chain fused(More)
How features of the visual scene are encoded in the population activity of retinal ganglion cells (RGCs) targeting specific regions of the brain is not well understood. To address this, we have used a genetically encoded reporter of presynaptic function (SyGCaMP3) to record visually evoked activity in the population of RGC axons innervating the zebrafish(More)
How local circuits within the brain process visual information has classically been addressed at the single neuron level. Such reductionist approaches, however, struggle to capture the full scope of functional properties associated with even "simple" brain nuclei. Using population functional calcium imaging, we aim to describe how local circuits within the(More)
We have examined the form, diversity, and organization of three functional classes of retinal inputs to the zebrafish optic tectum during development. Our systems-based approach was to analyze data from populations of retinal ganglion cells labeled with a presynaptic targeted calcium indicator, synaptophysin GCaMP3 (SyGCaMP3). Collectively, our findings(More)
Genetically encoded calcium indicators (GECIs) allow repeated, non-invasive measurements of neural activity in defined populations of neurons, but until recently GECIs based on single fluorescent proteins have been limited to the green region of the color spectrum. Recent efforts in protein engineering have expanded the color palette of GECIs. One of these(More)
The study of nervous system development has been greatly facilitated by recent advances in molecular biology and imaging techniques. These approaches are perfectly suited to young transparent zebrafish where they have allowed direct observation of neural circuit assembly in vivo. In this review we will highlight a number of key studies that have applied(More)
The PSD-95 family of membrane- associated guanylate kinases (MAGUKs) are thought to act as molecular scaffolds that regulate the assembly and function of the multiprotein signaling complex found at the postsynaptic density of excitatory synapses. Genetic analysis of PSD-95 family members in the mammalian nervous system has so far been difficult, but the(More)