Insulin and Leptin Signaling Interact in the Mouse Kiss1 Neuron during the Peripubertal Period.

Reproduction requires adequate energy stores for parents and offspring to survive. Kiss1 neurons, which are essential for fertility, have the potential to serve as the central sensors of metabolic factors that signal to the reproductive axis the presence of stored calories. Paradoxically, obesity is often accompanied by infertility.

Effects of near-infrared laser exposure in a cellular model of wound healing.

Background: Clinical studies have demonstrated beneficial outcomes for low-level laser therapy (LLLT) using near-infrared (NIR) wavelengths. It has been hypothesized that the benefits of NIR LLLT are due in part to the thermal effects of NIR exposure. However, it is not clear whether photochemical interactions between NIR light and superficial tissues contribute to beneficial outcomes.

MATLAB-based Simulation of Whole-Cell and Single-Channel Currents.

Mathematical models of electrophysiological data are used to investigate biophysical mechanisms that underlie electrical excitability. Although the resources and time required for obtaining experimental data to create these models may not be available to undergraduates enrolled in a biophysics course, computational tools that simulate cellular or single-channel responses to electrophysiological stimuli can be utilized to provide these data. We have developed two MATLAB-based simulation packages that are being used in a cellular electrophysiology course for upper-level undergraduate engineering students to demonstrate the design of electrophysiological stimuli, and the analysis and modeling of ionic currents in excitable tissues.

Tyramine receptor (SER-2) isoforms are involved in the regulation of pharyngeal pumping and foraging behavior in Caenorhabditis elegans.

Octopamine regulates essential processes in nematodes; however, little is known about the physiological role of its precursor, tyramine. In the present study, we have characterized alternatively spliced Caenorhabditis elegans tyramine receptor isoforms (SER-2 and SER-2A) that differ by 23 amino acids within the mid-region of the third intracellular loop. Membranes prepared from cells expressing either SER-2 or SER-2A bind [3H]lysergic acid diethylamide (LSD) in the low nanomolar range and exhibit highest affinity for tyramine.

Subthreshold oscillations generated by TTX-sensitive sodium currents in dorsal cochlear nucleus pyramidal cells.

During intracellular recordings in rodent brainstem slice preparations, dorsal cochlear nucleus (DCN) pyramidal cells (PCs) exhibit characteristic discharge patterns to depolarizing current injection that depend on the membrane potential from which the responses are evoked. When depolarized from hyperpolarized potentials, PCs can respond with a short-latency action potential followed by a long silent interval (pauser) or a train of action potentials with a long latency (buildup). During the silent intervals in a pauser or a buildup response, the membrane potential slowly depolarizes towards spike threshold, often exhibiting distinct voltage oscillations of 1-2 mV before the first spike.

Dendritic Ca2+ transients evoked by action potentials in rat dorsal cochlear nucleus pyramidal and cartwheel neurons.

Simultaneous fluorescence imaging and electrophysiologic recordings were used to investigate the Ca(2+) influx initiated by action potentials (APs) into dorsal cochlear nucleus (DCN) pyramidal cell (PC) and cartwheel cell (CWC) dendrites. Local application of Cd(2+) blocked Ca(2+) transients in PC and CWC dendrites, demonstrating that the Ca(2+) influx was initiated by dendritic Ca(2+) channels. In PCs, TTX eliminated the dendritic Ca(2+) transients when APs were completely blocked.