Remote Control of Neuronal Activity in Transgenic Mice Expressing Evolved G Protein-Coupled Receptors

Abstract

Examining the behavioral consequences of selective CNS neuronal activation is a powerful tool for elucidating mammalian brain function in health and disease. Newly developed genetic, pharmacological, and optical tools allow activation of neurons with exquisite spatiotemporal resolution; however, the inaccessibility to light of widely-distributed neuronal populations and the invasiveness required for activation by light or infused ligands limit the utility of these methods. To overcome these barriers, we created transgenic mice expressing an evolved G protein-coupled receptor (hM3Dq) selectively activated by the pharmacologically inert, orally bioavailable drug clozapine-N-oxide (CNO). Here, we expressed hM3Dq in forebrain principal neurons. Local field potential and single neuron recordings revealed that peripheral administration of CNO activated hippocampal neurons selectively in hM3Dq-expressing mice. Behavioral correlates of neuronal activation included increased locomotion, stereotypy, and limbic seizures. These results demonstrate a novel and powerful chemical-genetic tool for remotely controlling the activity of discrete populations of neurons in vivo.

Hypothalamic CNTF volume transmission shapes cortical noradrenergic excitability upon acute stress

“…Secondly, they invariably responded to AMPA superfusion by generating long‐lasting inward currents when held at −70 mV (Fig 1E). We then addressed whether glutamatergic innervation of ependymal cells originates from CRH neurons by microinjecting adeno‐associated virus (AAV) particles carrying Cre‐dependent activating DREADD (hM3Dq) in tandem with an mCherry reporter (Alexander et al , 2009) into the PVN (Fig 1F). Histochemical localization of mCherry recapitulated the distribution of VGLUT2 + synaptic puncta along ventricular ependyma (Fig 1F1), supporting the existence of a direct projection from parvocellular CRH neurons.…”

“…We have tested this hypothesis by injecting AAV particles carrying Cre‐dependent DREADD expression systems for neuronal activation (hM3Dq; Alexander et al , 2009) or inactivation (hM4Di; Armbruster et al , 2007) into the LC of Scgn ‐Cre mice (Fig 4H). Once placing CNO pre‐treated animals (10 min; 2 mg/kg) into an open field, we find that chemogenetic NE activation induces freezing, rendering the animals persistently immobile (Figs 4H1 and Movies EV1, EV3A; EV2 and EV3).…”

Pharmacogenetic activation of midbrain dopaminergic neurons induces hyperactivity

“…518 relatively large area of the midbrain [2] . In this study, we tested whether the activation of midbrain dopaminergic neurons affects motor activity with a pharmacogenetic tool [9,10] . The gene encoding the evolved hM3Dq receptor was targeted into midbrain dopaminergic neurons by stereotaxic injection of a Cre-inducible AAV viral vector [11,12] .…”

Selective Manipulation of Neural Circuits

“…The first DREADD system mutated the muscarinic acetylcholine receptor so that it is only activated by clozapine-N-oxide, an inactive metabolite of the central nervous system drug clozapine [146,148,149]. The muscarinic DREADD receptor is coupled to Gq, which is an excitatory channel that depolarizes neurons and enhances their excitability through phospholipase C [146,150]. A chimeric muscarinic-adrenergic receptor DREADD known as GsD also activates neurons but via cyclic adenosine monophosphate-mediated signaling [149,151].…”

“…In terms of choosing of tools for experiments, optogenetics allow precise temporal alterations of function. Chemogenetics, especially DREADDs are more appropriate than optogenetics for changes of behaviors, which requires prolonged testing as DREADD activity is sustained for several hours after 1 injection of the ligand [41,150,151,153]. In addition, chemogenetics also can be done without a headmounted light source and invasive fiber optics.…”