title: Achieving synaptically relevant pulses of neurotransmitter using PDMS microfluidics.
abstract: Fast synaptic transmission is mediated by post-synaptic ligand-gated ion channels (LGICs) transiently activated by neurotransmitter released from pre-synaptic vesicles. Although disruption of synaptic transmission has been implicated in numerous neurological and psychiatric disorders, effective and practical methods for studying LGICs in vitro under synaptically relevant conditions are unavailable. Here, we describe a novel microfluidic approach to solution switching that allows for precise temporal control over the neurotransmitter transient while substantially increasing experimental throughput, flexibility, reproducibility, and cost-effectiveness. When this system was used to apply ultra-brief ( approximately 400micros) GABA pulses to recombinant GABA(A) receptors, members of the cys-loop family of LGICs, the resulting currents resembled hippocampal inhibitory post-synaptic currents (IPSCs) and differed from currents evoked by longer, conventional pulses, illustrating the importance of evaluating LGICs on a synaptic timescale. This methodology should therefore allow the effects of disease-causing mutations and allosteric modulators to be evaluated in vitro under physiologically relevant conditions.
authors.affiliation: Graduate Program in Neuroscience, Vanderbilt University, 465 21st Avenue South, MRBIII, Suite 6140, Nashville, TN 37232, United States. manuel.botzolakis@vanderbilt.edu <manuel.botzolakis@vanderbilt.edu>
authors.forename: E J
authors.initials: EJ
authors.lastname: Botzolakis
authors.forename: A
authors.initials: A
authors.lastname: Maheshwari
authors.forename: H J
authors.initials: HJ
authors.lastname: Feng
authors.forename: A H
authors.initials: AH
authors.lastname: Lagrange
authors.forename: J H
authors.initials: JH
authors.lastname: Shaver
authors.forename: N J
authors.initials: NJ
authors.lastname: Kassebaum
authors.forename: R
authors.initials: R
authors.lastname: Venkataraman
authors.forename: F
authors.initials: F
authors.lastname: Baudenbacher
authors.forename: R L
authors.initials: RL
authors.lastname: Macdonald
mesh_terms: D000494:Allosteric Regulation / Q000187:drug effects / Q000502:physiology; D002460:Cell Line; D016503:Drug Delivery Systems / Q000295:instrumentation / Q000379:methods*; D004582:Electronics, Medical / Q000295:instrumentation / Q000379:methods; D004594:Electrophysiology / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D053444:Inhibitory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods*; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology; D009448:Neurochemistry / Q000295:instrumentation / Q000379:methods; D018377:Neurotransmitter Agents / Q000378:metabolism* / Q000494:pharmacology; D018408:Patch-Clamp Techniques / Q000295:instrumentation / Q000379:methods; D017729:Presynaptic Terminals / Q000187:drug effects / Q000378:metabolism; D011963:Receptors, GABA-A / Q000187:drug effects / Q000378:metabolism; D011994:Recombinant Proteins / Q000187:drug effects / Q000378:metabolism; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors
chemical_list: D018377:Neurotransmitter Agents; D011963:Receptors, GABA-A; D011994:Recombinant Proteins