Insulin-like growth factor-I (IGF-I) is emerging as an important growth factor able to modulate the programmed cell death (PCD) pathway mediated by the cysteine-dependent aspartate proteases (caspases); however, little is known about the effect of IGF-I after nerve growth factor (NGF) withdrawal in neurons. To begin to understand the neuronal death-sparing effect of IGF-I under NGF-free conditi...

The prion diseases occur following the conversion of the cellular prion protein (PrPC) into an alternatively folded, disease-associated isoform (PrPSc). However, the spread of PrPSc from cell to cell is poorly understood. In the present manuscript we report that soluble PrPSc bound to and replicated within both GT1 neuronal cells and primary cortical neurons. The capacity of PrPSc to bind and r...

Although it is widely accepted that an activity-dependent gene transcription is induced by the calcium (Ca(2+)) signals in neurons, it is still unclear how the particular mRNA moieties are transiently accumulated in response to synaptic transmission that evokes multiple intracellular signals including Ca(2+) and cAMP ones. Promoters of the brain-derived neurotrophic factor (BDNF) and the pituit...

Previous studies have shown that exposing hippocampal slices to low osmolarity (pi(o)) or to low extracellular NaCl concentration ([NaCl](o)) enhances synaptic transmission and also causes interstitial calcium ([Ca(2+)](o)) to decrease. Reduction of [Ca(2+)](o) suggests cellular uptake and could explain the potentiation of synaptic transmission. We measured intracellular calcium activity ([Ca(2...

Glucagon-like peptide-2 (GLP-2) is a nutrient-responsive neuropeptide that exerts diverse actions in the gastrointestinal tract, including enhancing mucosal cell survival and proliferation. GLP-2 stimulates mucosal growth in vivo with an increased rate of protein synthesis. However, it was unclear whether GLP-2 can directly stimulate protein synthesis. The objective was to test critically wheth...

We have recently isolated and identified a brain specific Na(+)-dependent inorganic phosphate (Pi) cotransporter cDNA (rBNPI) from a rat brain cDNA library (Ni, et al., 1994). We now report the regional and developmental expression, as well as the cellular localization, of rBNPI mRNA in the rat brain. In situ hybridization histochemistry reveals that rBNPI mRNA is selectively expressed in neuro...

Intracellular recordings of jejunal myenteric neurons with an afterspike hyperpolarization (AH) from Trichinella spiralis-infected animals showed enhanced excitability on days 3, 6, and 10postinfection (PI) compared with uninfected animals. Lower membrane potential, increased membrane input resistance, decreased threshold for action potential discharge, decreased AH amplitude and duration, and ...

Planning and directing thought and behavior require the working memory (WM) functions of prefrontal cortex. WM is compromised by stress, which activates phosphatidylinositol (PI)-mediated IP3-PKC intracellular signaling. PKC overactivation impairs WM operations and in vitro studies indicate that IP3 receptor (IP3R)-evoked calcium release results in SK channel-dependent hyperpolarization of pref...

A feedforward Sigma-Pi neural network with a single hidden layer of m neurons is given by mSigma(j=1) cjg (nPi(k=1) xk-thetak(j)/lambdak(j)) where cj, thetak(j), lambdak are elements of R. In this paper, we investigate the approximation of arbitrary functions f: Rn-->R by a Sigma-Pi neural network in the Lp norm. An Lp locally integrable function g(t) can approximate any given function, if and ...

background and objective: evaluation of degenerative changes of motoneurons and their related synapses can be useful in understanding the mechanisms of neurodegenerative diseases and their potential treatment. the present electron microscopic and immunohistochemical study investigates the axotomy-induced changes of adult spinal motoneurons up to 3 months following sciatic nerve transection. mat...