This seminar will begin at 4:00 pm at the Jerome L. Greene Science Center on Columbia University’s Manhattanville campus (L7-119). Light refreshments will be available starting at 3:30 pm.
This month's speakers:
Heike Blockus (Polleux lab): "A Novel Neurexin-Slit-Robo2 Complex Links Synaptic Specificity to Circuit Function in the Hippocampus"
The degree of synaptic specificity that characterizes circuits of the mammalian central nervous system and determines behavioral repertoires is remarkable, but the molecular mechanisms underlying synaptic specificity remain poorly understood. We identified a novel tripartite Neurexin-Slit-Robo2 trans-synaptic adhesion complex that instructs excitatory synapse formation between specific classes of hippocampal pyramidal neurons (PNs). Cell-autonomous deletion of Robo2 from CA1 pyramidal neurons leads to a drastic reduction of the excitatory synapses that they receive from CA3/CA2 but has no effect on synapses deriving from the entorhinal cortex (EC). Using in vivo Ca2+ 2-photon imaging of CA1 PNs, we find that developmental deletion of Robo2 from CA1 PNs results in decreases in place cell fraction, sensitivity, and — most significantly — place cell stability. Our results identify a novel molecular effector of synaptic specificity with critical effects on circuit function in vivo.
Eviatar Yemini (Hobert lab): "NeuroPAL: A Neuronal Polychromatic Atlas of Landmarks for Whole-Brain Imaging in C. elegans"
The identification of neuronal patterns of activity, gene expression, & mutant effects represents a major challenge when investigating neural circuitry. I introduce a multicolor nematode strain, called the NeuroPAL (a Neuronal Polychromatic Atlas of Landmarks), to resolve unique neural identities in whole-brain images. All NeuroPAL worms share an identical color map, permitting unambiguous determination of individual neuron names when using GCaMP/GFP/CFP/YFP reporters. I will present the results of several broad NeuroPAL applications.