Quantitative chemical composition of cortical GABAergic neurons revealed in transgenic venus-expressing rats.
Although neocortical GABAergic (gamma-aminobutyric acidergic) interneurons have been the focus of intense study, especially in the rat, a consensus view of the functional diversity and organization of inhibitory cortical neurons has not yet been achieved. To better analyze GABAergic neurons in the rat, we used a bacterial artificial chromosome (BAC) construct and established 2 lines of transgenic rats that coexpress Venus, a yellow fluorescent protein, with the vesicular GABA transporter. The brain GABA content from both transgenic lines was similar to the level found in wild-type rats. In the frontal cortex, Venus was expressed in >95% of GABAergic neurons, most of which also expressed at least one of 6 biochemical markers, including alpha-actitin-2, which preferentially labeled late-spiking neurogliaform cells. Taking advantage of the fact that Venus expression allows for targeted recording from all classes of nonpyramidal cells, irrespective of their somatic morphologies, we demonstrated that fast-spiking neurons, which were heterogeneous in somatic size as well as vertical dendritic projection, had relatively uniform horizontal dimensions, suggesting a cell type-specific columnar input territory. Our data demonstrate the benefits of VGAT-Venus rats for investigating GABAergic circuits, as well as the feasibility of using BAC technology in rats to label subsets of specific, genetically defined neurons.
Uematsu
Masakazu
M
Laboratory of Neurochemistry, National Institute for Physiological Sciences (NIPS), Okazaki 444-8585, Japan.
Hirai
Yasuharu
Y
Karube
Fuyuki
F
Ebihara
Satoe
S
Kato
Megumi
M
Abe
Kuniya
K
Obata
Kunihiko
K
Yoshida
Sachiko
S
Hirabayashi
Masumi
M
Yanagawa
Yuchio
Y
Kawaguchi
Yasuo
Y
D000818:Animals; D030801:Animals, Genetically Modified; D001426:Bacterial Proteins; D001931:Brain Mapping / Q000379:methods*; D002540:Cerebral Cortex / Q000378:metabolism*; D007395:Interneurons / Q000378:metabolism*; D008164:Luminescent Proteins; D008856:Microscopy, Fluorescence / Q000379:methods; D009433:Neural Inhibition / Q000502:physiology*; D051381:Rats / Q000235:genetics; D009435:Synaptic Transmission / Q000502:physiology*; D014018:Tissue Distribution; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D001426:Bacterial Proteins; D008164:Luminescent Proteins; C054562:yellow fluorescent protein, Bacteria; D005680:gamma-Aminobutyric Acid