神经生物学

Normal development and homeostasis result from a tenuous balance between cell proliferation and cell death. Disruption of this balance, in favor of cell death in particular, could easily lead to pathological states in postmitotic organs such as the adult brain (see Thompson, 1995). For exam ...

Naturally occurring cell death (NOCD) has been recognized for many years as a critical phase in the development of the nervous system (Hamburger and Levi-Montalcini, 1949; Oppenheim, 1991). During this process, immature neurons undergo an active process of cell death, probably because th ...

During embryogenesis of vertebrates, programmed cell death (or apoptosis) is an important event involved in tissue formation and organogenesis (Ernst, 1926; Gl�cksmann, 1951; Kerr et al., 1972). In the nervous system, programmed cell death of sensory and motor neurons occurs in embryonic s ...

In recent years, we have studied cell death in the developing nervous system (Owens et al., 1995), in fetal tissue grafts (Mahalik et al., 1995), and in the rodent olfactory epithelium (Mahalik, 1995). In addition, we are interested in correlating cell death in the rodent CNS with the expression of a putati ...

Apoptosis is one type of programmed cell death responsible for the physiological elimination of various cell populations during development (Wyllie, 1988). It has been estimated that up to 50% or more of vertebrate neurons in the central nervous system (CNS) die during embryonic developm ...

Apoptosis is a mode of cell death that has been defined largely on the basis of morphology (Wyllie et al, 1980; Clarke, 1990). The primary criteria used to delineate cell death as “apoptotic” are the condensation of nuclear chromatin and the fragmentation of nuclear DNA into oligonucleosomal-si ...

Apoptosis is an active process of selective cell death that occurs during development and has been implicated in the pathogenesis of a variety of human diseases (Thompson, 1995). Apoptosis can be distinguished from the other major form of cell death, necrosis, on the basis of both morphological ...

DNA fragments of discrete sizes, multiples of monomeric units, have clearly been observed during the period of nuclear degeneration of the terminal lens cell differentiation (Appleby and Modak, 1977). The same puzzling phenomenon has been associated with thymocyte apoptoses (Wyll ...

Our understanding of apoptosis and programmed cell death has rapidly evolved over the last decade. As originally conceived, apoptosis was a purely morphological phenomena based on the appearance of membrane blebbing (apoptotic bodies) and nuclear changes, including chromatin co ...

It is well known that cell death forms an important part of normal developmental and plastic processes in the brain. For example, during development, proliferating neuronal precursors generate a population of differentiated neurons, some of which make contact with their targets and sur ...

Although synaptosomes are a widely accepted preparation for studying regulation of transmitter release at the isolated presynaptic level (see also Chapter 4), they are not suited for the investigation of synaptic events mediated by postsynaptic mechanisms. In the past, isolated mem ...

Neuropeptides constitute the largest and most diverse class of signaling substances known in metazoans. Over the last 20 yr it has become apparent that neuropeptides have important roles as neurohormones, neuromodulators, cytokines, morphogenetic factors, and possibly in some c ...

It is generally thought that up to 90% of all synapses in the mammalian brain use amino acids as neurotransmitters (1). Neurotransmitter amino acids may either be those that are also used directly as protein constituents (such as glutamate) or modified amino acids, such as γ-amino butyric acid (GAB ...

Brain tissue is extremely heterogeneous—being comprised of neurons (which are often myelinated) and a number of glial cell types—and, therefore, requires some purification in order to study neuronal and glial functioning in isolation at the molecular level. The introduction of the ult ...

Immunocytochemistry (ICC) of small, water-soluble molecules requires some special precautions compared to ICC of large protein molecules. In general, protein antigens are relatively insensitive to the type of fixative used. Apparently, the epitopes are not altered in a decisive way ...

Exocytotic fusion of secretory vesicles with the plasma membrane occurs in cells in either a constitutive or regulated fashion (Burgess and Kelly, 1987). Constitutive exocytosis is the mechanism by which membrane components and certain soluble proteins are released. In the regulated ...

Rod and cone photoreceptors transduce the absorption of a photon of light into an electrical response. Within the last decade, our understanding of photoreceptors has increased enormously, and this growth in understanding has resulted in large part from the application of new electrop ...

Invertebrate phototransduction is a central subject in neuroscience that includes several key topics with implications to a wide variety of cells and tissues. The phototransduction cascade begins with isomerization of the retinoid chromophore by photons that activate the phot ...

Inositol 1,4,5-trisphosphate (Ins(1,4,5)P 3) was first shown to stimulate mobilization of intracellular Ca2+ from permeabilized pancreatic acinar cells (Streb et al., 1983) and has since become recognized as an intracellular messenger formed after receptor activation and then res ...

There is now compelling evidence that stimulation of inosito1 phospholipid metabolism via phosphoinositidase C (MC) is the signal transduction pathway for a wide variety of receptors in the mammalian nervous system. A by no means comprehensive list is shown in Table 1. Receptors are thoug ...