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A L Politoff

Publications and source records attributed to A L Politoff.

4 recordsLinked to original sources

Decreased alpha bandwidth responsiveness to photic driving in Alzheimer disease.

The power spectra of the photically activated occipital EEGs of 9 mildly to moderately demented probable Alzheimer disease (AD) patients (according to NINCDS-ADRDA criteria), 9 normal age-matched control and 27 normal subjects of different ages were compared. In normal subjects, photic stimulation with rhythmic flashes ranging between 2 and 20 Hz elicited a characteristic response in each EEG bandwidth (delta, theta, alpha, beta1 and beta2). The magnitude of each bandwidth response was a function of the frequency of the photic stimulus. In AD patients the alpha bandwidth response curve was significantly smaller than that of age-matched controls (MANOVA main effect of group, P = 0.018); all the other bandwidth response curves were normal. Therefore, in AD there is a selective abnormality in the alpha bandwidth responsiveness to photic stimulation, probably due to AD pathology in the neuronal generator of the alpha rhythm.

Aged

Neurotrophic control of RNA synthesis in amphibian striated muscle.

When frog sartorius muscles are incubated in culture for 3 days, a 98% increase in RNA synthesis by the muscles is seen. A portion of this increase (60--100% in different experiments) is prevented by the presence of a 2 cm distal nerve stump left attached to the muscle, or by the addition to the culture medium of nerve and spinal cord extracts from frog, rat or cow. The effect of the nerve stump and the extract is seen under conditions of neuro-muscular blockade by 50 mg/l gentamicin sulfate present in the culture medium. Autoradiography of 1 micrometer sections of muscles previously labeled with [3H]uridine shows that isotope incorporation is largely confined to muscle fibers rather than connective tissue. Muscles cultured for 3 days display normal action and resting potentials either in the presence or absence of extract. The results are discussed in terms of control of muscle RNA synthesis by substances present in motor neurons.

Action Potentials