The Laboratory of Cellular and Synaptic Neurophysiology uses the techniques
of neurophysiology, molecular biology, and cell biology to study signalling
mechanisms related to the development, physiology, and pathophysiology
of the mammalian central nervous system. Specifically, we study receptors,
ion channels, and signalling mechanisms in preparations that range from
isolated cells to highly ordered neural networks in physiological and
pathophysiological conditions in both wild-type and transgenic animals.
Problems under analysis concern mechanisms of short- and long-term plasticity
of synaptic transmission, neurotrophin regulation of excitability and
development, differential targeting of synaptic receptors, neuron-glial
signalling, pathophysiological processes in clinically relevant neuronal
migration disorders, ion channel regulation of development and excitability,
and drug action at a variety of voltage- and ligand-gated receptors.
During the last year, Chris McBain conducted an extensive characterization
of Ca2+-permeable, GluR2-lacking AMPA-, and NMDA-receptors at hippocampal
inhibitory interneuron synapses. His group elucidated the time course
of electrotonically overlapping but kinetically distinct synaptic conductances
on inhibitory interneuron dendrites and the roles of voltage-gated conductances
in the generation of muscarinic receptor– and kainate receptor–induced
hippocampal gamma oscillatory activity. Doug Fields elucidated the role
of adenosine as a neuron-glial transmitter that promotes myelination
in the central nervous system in response to action potential activity.
He also studied the role of electrical activity in regulating late-phase
long-lasting synaptic plasticity. Bai Lu worked on activity- and tyrosine
kinase–dependent facilitation of trkB receptor internalization
in hippocampal neurons and discovered the presence of single nucleotide
polymorphisms in the BDNF gene and the role played by the polymorphisms
in BDNF secretion and hippocampal function, with particular reference
to memory formation. James Russell investigated the kinetics
of Ca2+ release from Ca2+-signalling microdomains and the pattern of type 2 IP3Rs
expressed by astrocytes in situ.
Both Drs. Fields and Lu gained tenure. Dr. McBain was elected to the
editorial board of the Journal of Physiology and Journal of Neuroscience.
Finally, the laboratory made considerable effort to recruit two independent
researchers to the NICHD tenure track: in fall 2002, Drs. Dax Hoffman
and Mark Stopfer joined the LCSN. Dax Hoffman combines patch clamp
recording in brain slices of hippocampus with molecular biology techniques
to investigate
the electrophysiological properties and molecular nature of the voltage-gated
channels expressed in CA1 dendrites. Mark Stopfer combines imaging,
patch clamp physiology, and behavioral analysis to investigate synaptic
and
network mechanisms underlying sensory processing and memory formation,
including coding mechanisms involving the oscillatory interactions
of ensembles of interneurons in the insect antennal lobe.