The recording characteristics of the monopolar needle in three dimensions have not been well established. A simple spherical recording territory is commonly assumed with the very tip proposed to have a greater spatial recording sensitivity by some authors. We demonstrate by enlarged physical modeling in a homogeneous volume conductor that the recorded amplitude diminishes more gradually radiall...

According to the “standard model,” electric potentials such as the local field potential (LFP) or the electroencephalogram (EEG) are generated by current dipoles made by cerebral cortex neurons arranged in parallel. In this issue of Journal of Neurophysiology, Riera et al. (2012) present experimental evidence that this standard model may be insufficient to account for LFP and EEG signals in the...

In all cases, however, certain technical goals are essential, including control of hemorrhage, visibility, absence of harmful effects to the surgical site and adjacent tissues, postoperative comfort, and rapid healing. One modality that has been used historically to accomplish certain periodontal surgical procedures is electrosurgery. Conventional electrosurgery devices are monopolar, whereby t...

The spindle assembly checkpoint (SAC) functions as a surveillance mechanism to detect chromosome misalignment and to delay anaphase until the errors are corrected. The SAC is thought to control mitosis and meiosis, including meiosis in mammalian eggs. However, it remains unknown if meiosis in the eggs of nonmammalian vertebrate species is also regulated by SAC. Using a novel karyotyping techniq...

Meiosis differs from mitosis in that DNA replication is followed by the segregation of homologous chromosomes but not sister chromatids. This depends on the formation of interhomolog connections through crossover recombination and on the attachment of sister kinetochores to microtubules emanating from the same spindle pole. We show that in yeast, the Dbf4-dependent Cdc7 kinase (DDK) provides a ...

The fission yeast spindle pole body (SPB) comprises a cytoplasmic structure that is separated from an ill-defined nuclear component by the nuclear envelope. Upon mitotic commitment, the nuclear envelope separating these domains disperses as the two SPBs integrate into a hole that forms in the nuclear envelope. The SPB component Cut12 is linked to cell cycle control, as dominant cut12.s11 mutati...