Quantitative chemical composition of cortical GABAergic neurons revealed in transgenic Venus-expressing rats. Cereb Cortex

The first 2 authors contributed equally to this work. Although neocortical GABAergic (g-aminobutyric acidergic) inter-neurons 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 bio-chemical markers, including a-actitin-2, which preferentially la-beled late-spiking neurogliaform cells. Taking advantage of the fact that Venus expression allows for targeted recording from al