Biomedical subjects

K L Coburn

Publications and source records attributed to K L Coburn.

21 records · Page 2Linked to original sources

PubMed1985

The elgiloy microelectrode: fabrication techniques and characteristics.

A glass-insulated microelectrode made from elgiloy orthodontic wire, a stainless cobalt-chromium alloy containing 15% iron, was described by Suzuki and Azuma (1976). Here, we detail a set of modified electrode fabrication procedures, including techniques for hardening and etching the wire, specifying the size, geometry and exposure of the tip, and adjusting tip impedance over a wide range. Accurate insulation of the tip with molten solder glass produces microelectrodes suitable for extracellular recording from single or multiple units and simultaneous recording of evoked potentials. The finished electrode is tough enough to withstand multiple penetrations of the thickened, fibrous dura of the chronic monkey preparation. The iron content allows Prussian blue staining of marking lesions for histological verification of recording sites.

Alloys↗

PubMed1984

Taste potentiation of poisoned odor by temporal contiguity.

The synergistic interaction between odor and taste in flavor-toxicosis conditioning was tested in two experiments. The temporal interval between a 2-min odor and a 2-min taste was varied for thirsty rats licking at a water spout. In the first experiment, taste was presented at time zero, and odor was presented at -10, -1, 0, 1 and 10 min to independent groups in a simple compartment. In the second experiment, taste was presented at 0, and odor was presented at -5, -2, and 0 min in a "wind tunnel" apparatus. The results indicated that odor alone is an ineffective conditioned stimulus for a toxic unconditioned stimulus under our conditions, simultaneous (0-min) presentation of odor with taste potentiates the odor component so that it becomes more effective than the taste component, a 2-min interval between odor and taste attenuates potentiation, and a 5-min interval disrupts the effect, and the interaction in asymmetrical, that is, odor has no such systematic effect on the conditioning of taste.

Animals↗

PubMedDate not supplied

Delayed late component of visual global field power in probable Alzheimer's disease.

A substantial literature shows that late components of visual evoked potentials (VEPs) are delayed in at least some forms of dementia in the elderly. The late-component delay is selective in that earlier components are not affected. More recent work with better defined clinical groups suggests that the selective late-component delay may be characteristic of Alzheimer's disease (AD) rather than an inevitable feature of dementia in general. To overcome problems in traditional VEP component latency measurement the present study uses reference-free Global Field Power (GFP) analysis to more objectively define VEP components and finds that the GFP peak corresponding to the late P2 component of the flash VEP is delayed in a probable AD group but not in a demented unlikely AD group, relative to age-equivalent healthy controls. The late-component delay is again found to be selective in that the GFP peak corresponding to the earlier P1 component of the flash VEP does not differ between groups. These findings further strengthen the evidence for electrocortical changes in the visual system of AD patients.

Aged↗