Several properties of central cholinergic and dopaminergic neurons appear to be regulated in part by trophic factors originating from their target tissues. We propose to purify four of these factors and characterize their biological and chemical properties, using neuron-rich cultures of rat central neurons to assay trophic factor effects. In particular, we will study: (1) a factor made by muscle which enhances acetylcholine synthesis in spinal cord cultures, (2) a factor isolated from the neocortex which enhances acetylcholine synthesis and cholineacetyltransferase activity in cultures of rat basal forebrain cells. The activity of this factor is not blocked by antibodies against the classical nerve growth factor, and this factor does not affect spinal cord neurons. (3) a factor from the striatum which enhances dopamine synthesis in cultures of basal mesencephalon (includes substantia nigra) neurons, and (4) a serum-derived factor which greatly enhances the survival of both cholinergic and dopaminergic neurons. Bioassays will be used to follow the trophic activity through biochemical separation procedures. Immunological methods will be used to facilitate the final purification steps and obtain blocking antibodies to help in studying the biological functions of the factors. Purified trophic factor preparations will be tested to determine the range of their effects on target neurons (enhancement of transmitter synthesis, neurite outgrowth, ability to regenerate processes following trauma, and effects on cell survival, protein synthesis and electrophysiological membrane properties). We will also determine whether the trophic actions are reversible and modulatory, or irreversible and perhaps stage-specific. We plan also to extend these trophic factor studies to cultured primate neurons to determine whether the factors that are trophic for rat neurons also have similar actions on primate neurons, and whether primate tissues make similar trophic factors. Using fractions of serum from patients with neurodegenerative diseases affecting the brain regions we culture (amyotrophic lateral sclerosis, Parkinson's disease, Alzheimer's disease), we will test claims of specific neurotoxic serum factors, and determine whether these patients might have antibodies against the trophic factors and their receptors.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS012207-18
Application #
2262398
Study Section
Neurological Sciences Subcommittee 1 (NLS)
Project Start
1986-07-01
Project End
1995-06-30
Budget Start
1992-07-01
Budget End
1995-06-30
Support Year
18
Fiscal Year
1992
Total Cost
Indirect Cost
Name
University of Miami School of Medicine
Department
Physiology
Type
Schools of Medicine
DUNS #
City
Miami
State
FL
Country
United States
Zip Code
33146
White, Michael G; Saleh, Osama; Nonner, Doris et al. (2012) Mitochondrial dysfunction induced by heat stress in cultured rat CNS neurons. J Neurophysiol 108:2203-14
Chaverneff, Florence; Barrett, John (2009) Casein kinase II contributes to the synergistic effects of BMP7 and BDNF on Smad 1/5/8 phosphorylation in septal neurons under hypoglycemic stress. J Neurochem 109:733-43
Panickar, Kiran S; Nonner, Doris; White, Michael G et al. (2008) Overexpression of Cdk5 or non-phosphorylatable retinoblastoma protein protects septal neurons from oxygen-glucose deprivation. Neurochem Res 33:1852-8
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White, Michael G; Luca, Luminita E; Nonner, Doris et al. (2007) Cellular mechanisms of neuronal damage from hyperthermia. Prog Brain Res 162:347-71
Talbot, Janet; Barrett, John N; Barrett, Ellen F et al. (2007) Stimulation-induced changes in NADH fluorescence and mitochondrial membrane potential in lizard motor nerve terminals. J Physiol 579:783-98
Panickar, K S; Nonner, D; Barrett, J N (2005) Overexpression of Bcl-xl protects septal neurons from prolonged hypoglycemia and from acute ischemia-like stress. Neuroscience 135:73-80
White, Michael G; Emery, Michael; Nonner, Doris et al. (2003) Caspase activation contributes to delayed death of heat-stressed striatal neurons. J Neurochem 87:958-68
Vila, Lizette; Barrett, Ellen F; Barrett, John N (2003) Stimulation-induced mitochondrial [Ca2+] elevations in mouse motor terminals: comparison of wild-type with SOD1-G93A. J Physiol 549:719-28
Nonner, D; Barrett, E F; Barrett, J N (2000) Brief exposure to neurotrophins produces a calcium-dependent increase in choline acetyltransferase activity in cultured rat septal neurons. J Neurochem 74:988-99

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