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The "toxin-resistant" R-type Ca2+ channels are expressed widely in the CNS and distributed mainly in apical dendrites and spines. They play important roles in regulating signal transduction and intrinsic properties of neurons, but the modulation of these channels in the mammalian CNS has not been studied. In this study we used whole-cell patch-clamp(More)
Peripheral inflammation leads to a number of centrally mediated physiological and behavioral changes. The underlying mechanisms and the signaling pathways involved in these phenomena are not yet well understood. We hypothesized that peripheral inflammation leads to increased neuronal excitability arising from a CNS immune response. We induced inflammation(More)
Endocannabinoids (eCBs) are ubiquitous retrograde signaling molecules in the nervous system that are recruited in response to robust neuronal activity or the activation of postsynaptic G-protein-coupled receptors. Physiologically, eCBs have been implicated as important mediators of the stress axis and they may contribute to the rapid feedback inhibition of(More)
The magnocellular neurons of the hypothalamic supraoptic nucleus (SON) are a major source of both systemic and central release of the neurohypophyseal peptides, oxytocin (OXT) and arginine-vasopressin (AVP). Both OXT and AVP are released from the somatodendritic compartment of magnocellular neurons and act within the SON to modulate the electrophysiological(More)
Endothelin (ET-1) given centrally has many reported actions on hormonal and autonomic outputs from the CNS. However, it is unclear whether these effects are due to local ischemia via its vasoconstrictor properties or to a direct neuromodulatory action. ET-1 stimulates the release of oxytocin (OT) and vasopressin (VP) from supraoptic magnocellular (MNCs)(More)
Neural networks that regulate an organism's internal environment must sense perturbations, respond appropriately, and then reset. These adaptations should be reflected as changes in the efficacy of the synapses that drive the final output of these homeostatic networks. Here we show that hemorrhage, an in vivo challenge to fluid homeostasis, induces LTD at(More)
PURPOSE Cholinergic-dependent plateau potentials (PPs) are intrinsically generated conductances that can elicit ictal-type seizure activity. The aim of this study was to investigate the actions of topiramate (TPM) on the generation of PPs. METHODS We used whole-cell patch-clamp recordings from CA1 pyramidal neurons in rat hippocampal slices to examine the(More)
ATP release from astrocytes contributes to calcium ([Ca(2+)]) wave propagation and may modulate neuronal excitability. In epithelial cells and hepatocytes, cell swelling causes ATP release, which leads to the activation of a volume-sensitive Cl(-) current (I(Cl,swell)) through an autocrine pathway involving purinergic receptors. Astrocyte swelling is(More)
Exposure to a stressor sensitizes or 'primes' the hypothalamic-pituitary-adrenal axis to a subsequent novel stressor. The synaptic mechanisms underlying this priming, however, are not known. We found that exposing a rat to a single stressor primed glutamate synapses in the paraventricular nucleus of the hypothalamus and allowed them to undergo a short-term(More)
Plateau potentials are prolonged membrane depolarizations that are observed in hippocampal pyramidal neurons when spiking and Ca(2+) entry occur in combination with muscarinic receptor activation. In this study, we used whole-cell voltage clamping to study the current underlying the plateau potential and to determine the cellular signaling pathways(More)