Full-field electroretinogram response to increment and decrement stimuli.

Purpose: The d-wave is typically elicited after the termination of an increment flash, but a decrement flash provides an alternative, and perhaps more appropriate, stimulus to elicit the d-wave. Here, we investigated the affects of stimulus polarity on the electroretinogram (ERG) response.

Methods: ERG responses elicited to increment and decrement flashes of varying intensity and duration from different background levels were measured from human participants to assess the b-wave and d-wave responses as a function of adaptation level and flash polarity.

Apoptosis in oligodendrocytes is associated with axonal degeneration in P301L tau mice.

Transgenic mice overexpressing human tau with the P301L mutation develop neurofibrillary tangles, extensive gliosis, adult-onset motor abnormalities, and neuronal loss in affected brain regions. We investigated the mechanism of neuronal cell death in this model of tauopathy. There was no evidence of neuronal apoptosis at any age; however, a population of oligodendorocytes was immunopositive for TUNEL and activated caspase-3.