TINA M. WEATHERBY

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Speed of nerve impulse conduction is greatly increased by myelin, a multi-layered membranous sheath surrounding axons. Myelinated axons are ubiquitous among the vertebrates, but relatively rare among invertebrates. Electron microscopy of calanoid copepods using rapid cryofixation techniques revealed the widespread presence of myelinated axons. Myelin(More)
The sinus gland of Cardisoma carnifex was examined by light and transmission electron microscopy. This neurohemal organ is composed primarily of enlarged, branching axon terminals with numerous finger-like projections, which act as storage and release sites for neurohormones that are assumed to be contained in membrane-bound, electron-dense neurosecretory(More)
Aerobic methanotrophic bacteria consume methane as it diffuses away from methanogenic zones of soil and sediment. They act as a biofilter to reduce methane emissions to the atmosphere, and they are therefore targets in strategies to combat global climate change. No cultured methanotroph grows optimally below pH 5, but some environments with active methane(More)
The mechanoreceptors of the first antennae of Pleuromamma xiphias, a mesopelagic calanoid copepod, are critical for the detection of potential threats. These receptors exceed the physiological performance of other crustacean mechanoreceptors in sensitivity to water velocities as well as in frequency response. A study of these receptors was initiated to(More)
Calcium overload of neural cell mitochondria plays a key role in excitotoxic and ischemic brain injury. This study tested the hypothesis that brain mitochondria consist of subpopulations with differential sensitivity to calcium-induced inner membrane permeability transition, and that this sensitivity is greatly reduced by physiological levels of adenine(More)
Meninges, the connective tissue of the vertebrate central nervous system (CNS), have not been recognized in invertebrates. We describe the ultrastructure of the adult brain, antennules, and cord in five marine copepods: Calanus finmarchicus, Gaussia princeps, Bestiolina similis, Labidocera madurae, and Euchaeta rimana. In all of these locations we(More)
SUMMARY The sinus gland (a neurohaemal organ) and its nerve have been isolated from the eyestalk of the crabs Cardisoma carnifex and Portunus sanguino-lentus for studies correlating electrical responses recorded extra-cellularly from the sinus gland with hormone release. The appearance of erythrophore concentrating hormone (ECH) in the perfusate was(More)
The preparation of isolated peptidergic nerve terminals from the sinus gland (a neurohemal organ) of the crab (Cardisoma carnifex) is described. In this species the nerve endings can have diameters up to 30 microns. They release neurosecretory material as judged by the decrease in the volumetric density of granules upon depolarization with potassium.(More)
The mechanoreceptors of the ®rst antennae of Pleuromamma xiphias, a mesopelagic calanoid copepod, are critical for the detection of potential threats. These receptors exceed the physiological performance of other crustacean mechanoreceptors in sensitivity to water velocities as well as in frequency response. A study of these receptors was initiated to(More)
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