~15 - 30 %
||Tepper JM et al., Heterogeneity and Diversity of Striatal GABAergic Interneurons: Update 2018. Front Neuroanat. 2018 Nov 8 12: 91. doi: 10.3389/fnana.2018.00091 p.12 left column 3rd paragraphPubMed ID30467465
||Abstract: "In this review, [investigators] report on further advances in the understanding of the functional properties of previously reported striatal GABAergic interneurons and their synaptic connections. With the application of new transgenic fluorescent reporter and Cre-driver/reporter lines, plus optogenetic, chemogenetic and viral transduction methods, several additional subtypes of novel striatal GABAergic interneurons have been discovered, as well as the synaptic networks in which they are embedded."
||P.12 left column 3rd paragraph: "In structures such as the cortex and hippocampus, which are often used as model structures, interneurons make up about 15%–30% of the neuronal populations and are incredibly diverse with 10–15 different interneuron subtypes depending on the classification method."