ABSTRACT
Substance P (SP) is implicated in stress regulation and affective and anxiety-related behavior. Particularly high expression has been found in the main output region of the amygdala complex, the central amygdala (CE). Here we investigated the cellular mechanisms of SP in CE in vitro, taking advantage of glutamic acid decarboxylase-green fluorescent protein (GAD67-GFP) knockin mice that yield a reliable labeling of GABAergic neurons, which comprise 95% of the neuronal population in the lateral section of CE (CEl). In GFP-positive neurons within CEl, SP caused a membrane depolarization and increase in input resistance, associated with an increase in action potential firing frequency. Under voltage-clamp conditions, the SP-specific membrane current reversed at -101.5 ± 2.8 mV and displayed inwardly rectifying properties indicative of a membrane K(+) conductance. Moreover, SP responses were blocked by the neurokinin type 1 receptor (NK1R) antagonist L-822429 and mimicked by the NK1R agonist [Sar(9),Met(O2)(11)]-SP. Immunofluorescence staining confirmed localization of NK1R in GFP-positive neurons in CEl, predominantly in PKCδ-negative neurons (80%) and in few PKCδ-positive neurons (17%). Differences in SP responses were not observed between the major types of CEl neurons (late firing, regular spiking, low-threshold bursting). In addition, SP increased the frequency and amplitude of GABAergic synaptic events in CEl neurons depending on upstream spike activity. These data indicate a NK1R-mediated increase in excitability and GABAergic activity in CEl neurons, which seems to mostly involve the PKCδ-negative subpopulation. This influence can be assumed to increase reciprocal interactions between CElon and CEloff pathways, thereby boosting the medial CE (CEm) output pathway and contributing to the anxiogenic-like action of SP in the amygdala.
Subject(s)
Central Amygdaloid Nucleus/physiology , GABAergic Neurons/physiology , Receptors, Neurokinin-1/metabolism , Substance P/metabolism , Animals , Central Amygdaloid Nucleus/drug effects , Fluorescent Antibody Technique , GABAergic Neurons/drug effects , Gene Knock-In Techniques , Glutamate Decarboxylase/genetics , Glutamate Decarboxylase/metabolism , Green Fluorescent Proteins/genetics , Green Fluorescent Proteins/metabolism , Male , Membrane Potentials/drug effects , Membrane Potentials/physiology , Mice, Inbred C57BL , Mice, Transgenic , Neurokinin-1 Receptor Antagonists/pharmacology , Patch-Clamp Techniques , Piperidines/pharmacology , Potassium/metabolism , Protein Kinase C-delta/metabolism , Tissue Culture TechniquesABSTRACT
We investigate by angle-resolved photoemission the electronic structure of in situ grown tetragonal CuO, a synthetic quasi-two-dimensional edge-sharing cuprate. We show that, in spite of the very different nature of the copper oxide layers, with twice as many Cu in the CuO layers of tetragonal CuO as compared to the CuO(2) layers of the high-T(c) cuprates, the low-energy electronic excitations are surprisingly similar, with a Zhang-Rice singlet dispersing on weakly coupled cupratelike sublattices. This system should thus be considered as a member of the high-T(c) cuprate family, with, however, interesting differences due to the intralayer coupling between the cupratelike sublattices.
ABSTRACT
We report a comprehensive study of the paradigmatic quasi-1D compound (TaSe(4))(2)I performed by means of angle-resolved photoemission spectroscopy (ARPES) and first-principles electronic structure calculations. We find it to be a zero-gap semiconductor in the nondistorted structure, with non-negligible interchain coupling. Theory and experiment support a Peierls-like scenario for the charge-density wave formation below T(CDW)=263 K, where the incommensurability is a direct consequence of the finite interchain coupling. The formation of small polarons, strongly suggested by the ARPES data, explains the puzzling semiconductor-to-semiconductor transition observed in transport at T(CDW).
ABSTRACT
We show that in graphene epitaxially grown on SiC the Drude absorption is transformed into a strong terahertz plasmonic peak due to natural nanoscale inhomogeneities, such as substrate terraces and wrinkles. The excitation of the plasmon modifies dramatically the magneto-optical response and in particular the Faraday rotation. This makes graphene a unique playground for plasmon-controlled magneto-optical phenomena thanks to a cyclotron mass 2 orders of magnitude smaller than in conventional plasmonic materials such as noble metals.
ABSTRACT
Young children with sleep problems received either "standard" or graduated ignoring treatment. Both brief treatments were superior to a wait-list control condition and resulted in comparable improvements in bedtime and nighttime sleep problems. At bedtime, the treatments did not differ with respect to maternal compliance and stress. For nighttime wakings, mothers in the graduated ignoring group reported higher rates of compliance and less treatment-related stress. Maternal characteristics predicted treatment outcome in the standard ignoring condition. Following treatment, only positive side effects were observed. When compared to the wait-list group, mothers in the standard ignoring group reported less verbose discipline and decreased stress in parenting, while mothers in the graduated ignoring group reported improved parent-child relationships. Treatment gains were maintained over a 2-month follow-up period.
