Hugo L. Fernandez

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The major formed elements of axons of the ventral nerve cord of the crayfish are longitudinally oriented microtubules, filamentous matrix material, and mitochondria. Lanthanum staining delineates both microtubules and filamentous material to great advantage, and it is demonstrated that filamentous elements continuous with matrix material are associated with(More)
The main component of Alzheimer's disease (AD) amyloid deposits is amyloid beta-peptide (A beta), a fragment of the larger amyloid precursor protein (APP). The cellular source of A beta is not known, but a circulatory origin has been postulated. We studied human blood from healthy individuals and found that platelets account for almost 90% of the total(More)
The effects of internally and externally applied sulfhydryl reagents on the bioelectric properties of the giant axon of the squid Loligo pealeii and Dosidicus gigas were studied. Cysteine-HCl (400 mM, pH 7.3) was used to remove axoplasm from the perfusion channel. Oxidizing agents (1 to 60 mM) tended to increase the duration of the action potential and had(More)
This work addresses the physiological regulation of skeletal muscle acetylcholinesterase (AChE) isoforms by examining endplate-enriched samples from adult rat gracilis muscles 48 h after: lowintensity treadmill exercise; obturator nerve transection; nerve impulse conduction blockade by tetrodotoxin; acetylcholine (ACh) receptor (AChR) inactivation by(More)
Axoplasmic proteins in the crayfish nerve cord were labeled by the incorporation of high specific activity (3)H-leucine that was injected into one of the abdominal ganglia. The labeled proteins moved caudad as a sharply defined peak at 1.1 mm/day. The level of radioactivity in the cord decreased slowly as the peak approached the tail. From the sharpness of(More)
This work addresses the role of calcitonin gene-related peptide (CGRP) in the physiological maintenance of acetylcholinesterase (AChE) molecular forms in motor endplate regions of adult Sprague-Dawley rat fast-twitch anterior gracilis muscles. Results show that: (a) CGRP is present in obturator nerve motor neurons which supply the gracilis muscle, as well(More)
The characterization of individual acetylcholinesterase (AChE) molecular form subcellular pools in adult mammalian skeletal muscle is a critical point when considering such questions as the origin, assembly, and neurotrophic regulation of these molecules. By correlating the results of differential extraction, in vitro collagenase digestion, and in situ(More)
Axotomy-induced increase in 2-deoxyglucose (2-DG) uptake by motor nuclei and neuronal chromatolytic changes were studied after subepineural injection of colchicine into the motor nerve. Hypoglossal nuclei of either cats or rats were axotomized bilaterally, while one of the nerves was injected with colchicine or saline proximal to the site of nerve(More)
The state of intracellular Ca2+ in aging and in Alzheimer's disease (AD) is a key but highly controversial issue and direct measurement of the Ca2+ fluctuations in the living human brain has not been possible thus far. We therefore further considered this issue from a theoretical perspective. Ca2+ signaling mediates many life processes including:(More)
Calcitonin gene-related peptide (CGRP) has been implicated in the trophic regulation of acetylcholine receptors and G4 acetylcholinesterase at the rat neuromuscular junction. Since these latter molecules exhibit significant changes with advancing age, we examined the possibility that certain aspects of CGRP transport are also influenced by aging. Double(More)