Volodya Y. Hayrapetyan

Learn More
We examined the contribution of the nigrostriatal DA system to instrumental learning and behavior using optogenetics in awake, behaving mice. Using Cre-inducible channelrhodopsin-2 (ChR2) in mice expressing Cre recombinase driven by the tyrosine hydroxylase promoter (Th-Cre), we tested whether selective stimulation of DA neurons in the substantia nigra pars(More)
The prefrontal cortex (PFC) has been implicated in the maintenance of task-relevant information during goal-directed behavior. Using a combination of lesions, local inactivation, and optogenetics, we investigated the functional role of the medial prefrontal cortex (mPFC) in mice with a novel operant delayed alternation task. Task difficulty was manipulated(More)
Two gap junction proteins, connexin43 (Cx43) and connexin45 (Cx45), are coexpressed in many cardiac and other cells. Homomeric channels formed by these proteins differ in unitary conductance, permeability, and regulation. We sought to determine the ability of Cx43 and Cx45 to oligomerize with each other to form heteromeric gap junction channels and to(More)
Allosteric modulation of mouse 5-Hydroxytryptamine(3A) (5-HT(3A)) and 5-HT(3A/B) receptor function by ethanol and trichloroethanol (TCEt) was assessed in HEK293 cells with whole cell patch-clamp electrophysiological recordings. Ethanol enhanced 5-HT(3A) receptor function, but had no effect on mouse 5-HT(3A/B) receptor mediated currents. The enhancing action(More)
1 The goal of this study was to determine whether mutations of L293 at the 15' position of TM2 in the 5-HT(3A) receptor alter macroscopic current kinetics, and if these changes could account for alterations in alcohol modulation. Receptor function was assessed in Xenopus oocytes under voltage-clamp and in HEK293 cells with whole-cell patch-clamp recording(More)
Human neuroimaging studies suggest that aberrant neural connectivity underlies behavioural deficits in autism spectrum disorders (ASDs), but the molecular and neural circuit mechanisms underlying ASDs remain elusive. Here, we describe a complete knockout mouse model of the autism-associated Shank3 gene, with a deletion of exons 4-22 (Δe4-22). Both(More)
Huntington's disease (HD) is a neurodegenerative disease caused by the expansion of a poly-glutamine (poly-Q) stretch in the huntingtin (Htt) protein. Gain-of-function effects of mutant Htt have been extensively investigated as the major driver of neurodegeneration in HD. However, loss-of-function effects of poly-Q mutations recently emerged as potential(More)
Angelman syndrome (AS) is a neurodevelopmental disorder characterized by mental retardation and impaired speech. Because patients with this disorder often exhibit motor tremor and stereotypical behaviors, which are associated with basal ganglia pathology, we hypothesized that AS is accompanied by abnormal functioning of the striatum, the input nucleus of(More)
This report of the proceedings of a symposium presented at the 2005 annual meeting of the Research Society on Alcoholism highlights the actions of ethanol on purinergic (P2XRs) and 5-hydroxytryptamine3 (5-HT3Rs) receptors. Both P2XRs and 5-HT3Rs, are modulated by pharmacologically relevant concentrations of ethanol, with inhibition or stimulation of P2XR(More)
  • 1