GABAergic local circuit neurons are critical for the network activity and functional interaction of the amygdala and hippocampus. Previously, we obtained evidence for a GABAergic contribution to the hippocampal projection into the basolateral amygdala. Using fluorogold retrograde labeling, we now demonstrate that this projection indeed has a prominent GABAergic component comprising 17% of the G...

Formation of the normal mammalian cerebral cortex requires the migration of GABAergic inhibitory interneurons from an extracortical origin, the lateral ganglionic eminence (LGE). Mechanisms guiding the migratory direction of these neurons, or other neurons in the neocortex, are not well understood. We have used an explant assay to study GABAergic neuronal migration and found that the ventricula...

GABA is a key mediator of neural activity in the mammalian central nervous system, and a diverse set of GABAergic neurons utilize GABA as a transmitter. It has been widely accepted that GABAergic neurons typically serve as interneurons while glutamatergic principal cells send excitatory signals to remote areas. In general, glutamatergic projection neurons monosynaptically innervate both princip...

UNLABELLED It is generally thought that neurons in the thalamic reticular nucleus (TRN) form GABAergic synapses with other TRN neurons and that these interconnections are important for the function of the TRN. However, the existence of such intrinsic connections is controversial. We combine two complementary approaches to examine intrinsic GABAergic connections in the TRN of the mouse. We find ...

We have examined whether GABAergic neurons in the mesencephalic reticular formation (RFMes), which are believed to inhibit the neurons in the pons that generate paradoxical sleep (PS or REMS), are submitted to homeostatic regulation under conditions of sleep deprivation (SD) by enforced waking during the day in mice. Using immunofluorescence, we investigated first, by staining for c-Fos, whethe...

and ectopic expression, we demonstrated that Gata2 regulates GABAergic neuron development in the midbrain, but not in the rhombomere1. Without Gata2, all the precursors in the embryonic midbrain fail to activate GABAergic neuron-specific gene expression and switch to a glutamatergic phenotype instead. Surprisingly, this fate switch is also observed throughout the neonatal midbrain, except for t...

and ectopic expression, we demonstrated that Gata2 regulates GABAergic neuron development in the midbrain, but not in the rhombomere1. Without Gata2, all the precursors in the embryonic midbrain fail to activate GABAergic neuron-specific gene expression and switch to a glutamatergic phenotype instead. Surprisingly, this fate switch is also observed throughout the neonatal midbrain, except for t...

Visual responsiveness of cortical neurons changes depending on the brain state. Neural circuit mechanism underlying this change is unclear. By applying the method of in vivo two-photon functional calcium imaging to transgenic rats in which GABAergic neurons express fluorescent protein, we analyzed changes in visual response properties of cortical neurons when animals became awakened from anesth...

Basal forebrain GABAergic and cholinergic circuits regulate the activity of cholinergic projections to the cortex and hippocampus. Because these projections influence cortical development and function, the development of basal forebrain excitatory and inhibitory neurons is critical for overall brain development. We show that the neurotransmitter phenotype of these neurons is developmentally reg...

GABAergic projections from the neocortex to subcortical structures have been poorly characterized. Using Dlxi12b-Cre mice, we found anatomical evidence for GABAergic neurons that project from the mouse medial prefrontal cortex (mPFC) to multiple subcortical targets. We used a combination of patch-clamp electrophysiology, optogenetics, and pharmacology to confirm that Dlxi12b-labeled projections...