By studying mammalian olfactory neurons and odorant receptors, Richard Axel is pioneering studies on the molecular biology of sensory perception. Thomas Jessell studies the molecular mechanisms for development of the vertebrate nervous system. Through studies of Aplysia and mutant mice, Eric Kandel is elucidating the genes and molecular circuits that control learning and memory. Arthur Karlin is determining the mechanisms for signal recognition, gating, conductance and selectivity in neurotransmitter receptors. Oliver Hobert studies the molecular basis of neural circuit generation and behavioral patterns in C. elegans.
"The developing neural tube of a chick embryo", From Jessell and Ericson et al. Cell (1997) 90, p. 169-180.
Visualizing the olfactory sensory map: Neurons involved in smell (olfaction) have been genetically altered to express a protein that can stain them blue. From Mombaert and Axel et al. (1996) Cell, 87, 675-686.
Sonic Hedgehog signaling controls neuronal identity in the developing spinal cord. Illustration shows the expression of the sonic hedghog protein (yellow) in floor plate cells and its influence on cell pattern in the spinal cord and hindbrain. Sonic hedghog induces expression of the homeodomain protein Nkx2.2 (red) in the most ventral progenitor cells and restricts expression of Pax6 (green) to more dorsal progenitor cells. Motor neurons are defined by expression of the homeodomain protein Isl1 (blue) and derive both from Nkx2.2 and ventral Pax6 progenitor cells. Image provided by J.Ericson. Ericson J and Jessell, T. et al (1997) Cell 90, 169-80.
This photomicrograph shows a single presynaptic Aplysia sensory neuron making synaptic contact with two spatially separated postsynaptic motor neurons in culture. Injection of carboxyfluorescein (red) into the sensory neurons reveals the synapses (varicosities) formed by the sensory neuron onto each of the motor neurons. Repeated local application of serotonin onto the synaptic connections made with one of the motor neurons (in this case, the motor neuron in the upper right panel) produce synapse-specific, long-term facilitation. This long-term facilitation involves both synapse-specific increases in EPSP amplitude and synapse-specific growth. From the laboratory of Eric Kandel.
This photomicrograph shows MAPK staining in Aplysia sensory-motor cocultures following exposure to five pulses of serotonin, which produces long-term facilitation. MAPK translocates into the presynaptic but not the postsynaptic cell nucleus during long-term facilitation. From the laboratory of Eric Kandel.
Ventral view of two interneurons in the brain and the ventral nerve cord of C. elegans, visualized in live transgenic animals expressing a lin-11:GFP reporter gene construct. From the Hobert Laboratory