Delivery of different genes into pre- and post-synaptic neocortical interneurons connected by GABAergic synapses

Comparison of the clinical syndromes of anti-GABAa versus anti-GABAb associated autoimmune encephalitis: A systematic review

The main objective of this article is to improve our understanding of the differences and similarities of these two anti-gamma-aminobutyric acid receptor encephalitis, anti-GABAaR and anti-GABAbR. The data were systematically collected and we found 26 studies: seven studies and 37 patients corresponded to anti-GABAaR encephalitis, and 21 manuscripts and 116 patients were diagnosed with anti-GABAbR encephalitis. Both anti-GABAR encephalitis were marked by prominent seizures. Anti-GABAaR patients were younger and showed multifocal encephalitis. On the other hand, anti-GABAbR patients were older and showed temporal limbic encephalitis. Tumor occurred in a fifth of anti-GABAaR encephalitis and in half of anti-GABAbR encephalitis. The main tumor associated with anti-GABAbR encephalitis is SCLC, whereas the most common tumor associated with anti-GABAaR encephalitis was thymoma. Our data confirms the differences in clinical features between both encephalitis.

Recombinant Antibodies in Basic Neuroscience Research

Basic neuroscience research employs antibodies as key reagents to label, capture, and modulate the function of proteins of interest. Antibodies are immunoglobulin proteins. Recombinant antibodies are immunoglobulin proteins whose nucleic acid coding regions, or fragments thereof, have been cloned into expression plasmids that allow for unlimited production. Recombinant antibodies offer many advantages over conventional antibodies including their unambiguous identification and digital archiving via DNA sequencing, reliable expression, ease and reliable distribution as DNA sequences and as plasmids, and the opportunity for numerous forms of engineering to enhance their utility. Recombinant antibodies exist in many different forms, each of which offers potential advantages and disadvantages for neuroscience research applications. I provide an overview of recombinant antibodies and their development. Examples of their emerging use as valuable reagents in basic neuroscience research are also discussed. Many of these examples employ recombinant antibodies in innovative experimental approaches that cannot be pursued with conventional antibodies. © 2020 Wiley Periodicals LLC.

Efficient gene transfers into neocortical neurons connected by NMDA NR1-containing synapses

BACKGROUND

Within a circuit, specific neurons and synapses are hypothesized to have essential roles in circuit physiology and learning, and dysfunction in these neurons and synapses causes specific disorders. These critical neurons and synapses are embedded in complex circuits containing many neuron and synapse types.

NEW METHOD

We established technology that can deliver different genes into pre- and post-synaptic neurons connected by a specific synapse type. The first, presynaptic gene transfer employs standard gene transfer technology to express a synthetic peptide neurotransmitter which has three domains, a dense core vesicle sorting domain for processing the protein as a peptide neurotransmitter, a receptor-binding domain, here a small peptide that binds to NMDA NR1 subunits, and the His tag. Upon release, this peptide neurotransmitter binds to its cognate receptor on postsynaptic neurons. Gene transfer selectively into these postsynaptic neurons employs antibody-mediated, targeted gene transfer and anti-His tag antibodies, which recognize the His tag domain in the synthetic peptide neurotransmitter.

RESULTS

For the model system, we studied the connection from projection neurons in postrhinal cortex to specific neurons in perirhinal cortex. In our initial report, gene transfer to connected neurons was 20+1% specific. Here, we optimized the technology; we improved the transfection for packaging by using a modern using a modern lipid, Lipofectamine 3000, and used a modern confocal microscope to collect data. We now report 80+2% specific gene transfer to connected neurons.

COMPARISON WITH EXISTING METHODS

There is no existing method with this capability.

CONCLUSIONS

This technology may enable studies on the roles of specific neurons and synapses in circuit physiology and learning, and support gene therapy treatments for specific disorders.

Separate Gene Transfers into Pre- and Postsynaptic Neocortical Neurons Connected by mGluR5-Containing Synapses

mGluR5-containing synapses have essential roles in synaptic plasticity, circuit physiology, and learning, and dysfunction at these synapses is implicated in specific neurological disorders. As mGluR5-containing synapses are embedded in large and complex distributed circuits containing many neuron and synapse types, it is challenging to elucidate the roles of these synapses and to develop treatments for the associated disorders. Thus, it would be advantageous to deliver different genes into pre- and postsynaptic neurons connected by a mGluR5-containing synapse. Here, we develop this capability: The first gene transfer, into the presynaptic neurons, uses standard techniques to deliver a vector that expresses a synthetic peptide neurotransmitter. This peptide neurotransmitter has three domains: a dense core vesicle sorting domain, a mGluR5-binding domain composed of a single-chain variable fragment anti-mGluR5, and the His tag. Upon release, this peptide neurotransmitter binds to mGluR5, predominately located on the postsynaptic neurons. Selective gene transfer into these neurons uses antibody-mediated, targeted gene transfer and anti-His tag antibodies, as the synthetic peptide neurotransmitter contains the His tag. For the model system, we studied the connection between neurons in two neocortical areas: postrhinal and perirhinal cortices. Targeted gene transfer was over 80% specific for mGluR5-containing synapses, but untargeted gene transfer was only ~ 15% specific for these synapses. This technology may enable studies on the roles of mGluR5-containing neurons and synapses in circuit physiology and learning and support gene therapy treatments for specific disorders that involve dysfunction at these synapses.