JianXin Shen

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Ca2+ sparks are the elementary release events in many types of cells. Here we present a morphometric analysis of Ca2+ sparks (i.e., amplitude and kinetic parameters) using an approach that minimizes the confounding factor of the detection of out-of-focus events. By activation and visualization of Ca2+ sparks from Ca2+ release units under loose-seal(More)
Ca2+ ions passing through a single or a cluster of Ca2+-permeable channels create microscopic, short-lived Ca2+ gradients that constitute the building blocks of cellular Ca2+ signaling. Over the last decade, imaging microdomain Ca2+ in muscle cells has unveiled the exquisite spatial and temporal architecture of intracellular Ca2+ dynamics and has reshaped(More)
β-amyloid (Aβ) accumulation is described as a hallmark of Alzheimer’s disease (AD). Aβ perturbs a number of synaptic components including nicotinic acetylcholine receptors containing α7 subunits (α7-nAChRs), which are abundantly expressed in the hippocampus and found on GABAergic interneurons. We have previously demonstrated the existence of a novel,(More)
Tobacco use is a major public health problem. Nicotine acts on widely distributed nicotinic acetylcholine receptors (nAChRs) in the brain and excites dopamine (DA) neurons in the ventral tegmental area (VTA). The elicited increase of DA neuronal activity is thought to be an important mechanism for nicotine reward and subsequently the transition to(More)
Lamotrigine (LTG), an anticonvulsive drug, is often used for the treatment of a variety of epilepsies. In addition to block of sodium channels, LTG may act on other targets to exert its antiepileptic effect. In the present study, we evaluated the effects of LTG on neuronal nicotinic acetylcholine receptors (nAChRs) using the patch-clamp technique on human(More)
Alzheimer's disease (AD) is a neurodegenerative condition characterized by increased accumulation of Aβ and degeneration of cholinergic signaling between basal forebrain and hippocampus. Nicotinic acetylcholine receptors (nAChRs) are important mediators of cholinergic signaling in modulation of learning and memory function. Accumulating lines of evidence(More)
The α7 nicotinic acetylcholine receptor (α7 nAChR) is highly expressed in the brain, where it maintains various neuronal functions including (but not limited to) learning and memory. In addition, the protein expression levels of α7 nAChRs are altered in various brain disorders. The classic rule governing α7 nAChR assembly in the mammalian brain was that it(More)
AIMS To evaluate the acute effects of the mitochondrial complex I inhibitor rotenone on rat hippocampal synaptic plasticity. METHODS Electrophysiological field potential recordings were used to measure basal synaptic transmission and synaptic plasticity in rat coronal hippocampal slices. Synaptic long-term potentiation (LTP) was induced by high-frequency(More)
Cigarette smoking is associated with a decreased incidence of Parkinson disease (PD) through unknown mechanisms. Interestingly, a decrease in the numbers of α4β2 nicotinic acetylcholine receptors (α4β2-nAChRs) in PD patients suggests an α4β2-nAChR-mediated cholinergic deficit in PD. Although oligomeric forms of α-synuclein have been recognized to be toxic(More)
Human hypothalamic hamartoma (HH) is a rare developmental malformation often characterized by gelastic seizures, which are refractory to medical therapy. Ictal EEG recordings from the HH have demonstrated that the epileptic source of gelastic seizures lies within the HH lesion itself. Recent advances in surgical techniques targeting HH have led to dramatic(More)