Dscam1 Has Diverse Neuron Type-Specific Functions in the Developing CNS.

Two key features endow Down syndrome cell adhesion molecule 1 (Dscam1) with the potential to provide a ubiquitous code for neuronal arbor self-avoidance. First, Dscam1 contains three large cassettes of alternative exons, so that stochastic alternative splicing yields 19,008 Dscam1 isoforms with different Ig ectodomains. Second, each neuron expresses a different subset of Dscam1 isoforms, and isoform-specific homophilic binding causes repulsion.

Separation of presynaptic Ca2 and Ca1 channel function in synaptic vesicle exo- and endocytosis by the membrane anchored Ca pump PMCA.

Synaptic vesicle (SV) release, recycling, and plastic changes of release probability co-occur side by side within nerve terminals and rely on local Ca signals with different temporal and spatial profiles. The mechanisms that guarantee separate regulation of these vital presynaptic functions during action potential (AP)-triggered presynaptic Ca entry remain unclear. Combining genetics with electrophysiology and imaging reveals the localization of two different voltage-gated calcium channels at the presynaptic terminals of glutamatergic neuromuscular synapses (the Ca2 homolog, Dmca1A or cacophony, and the Ca1 homolog, Dmca1D) but with spatial and functional separation.

Dendritic and Axonal L-Type Calcium Channels Cooperate to Enhance Motoneuron Firing Output during Larval Locomotion.

Behaviorally adequate neuronal firing patterns are critically dependent on the specific types of ion channel expressed and on their subcellular localization. This study combines electrophysiology with genetic and pharmacological intervention in larval of both sexes to address localization and function of L-type like calcium channels in motoneurons. We demonstrate that Dmca1D (Ca1 homolog) L-type like calcium channels localize to both the somatodendritic and the axonal compartment of larval crawling motoneurons.