Purkinje neurons and granule neurons are two major cell populations in the cerebellar cortex. Purkinje neurons are well recognized by the size and complexity of their dentritic arbors. The numerous spines on the arbors serve as postsynaptic sites for reception of afferent input from the parallel fiber axons of granule neurons. The presynaptic axonal membranes, associated vesicles containing neurotransmitters and the thickened postsynaptic spinous membranes form structural complexes called synapses. The total number of synapses on Purkinje dendritic arbors of normally aging rats was known to be significantly reduced after chronic ethanol treatment, an effect that was reversed after recovery from the ethanol treatment. There were no ethanol-induced decreases in the number of parallel fibers because the number of granule neurons did not change. The overall size of the dendritic arbors was unchanged, but dendritic segments within the arbors were longer than normal following ethanol treatme nt, suggesting that some segments and their branch points had been deleted. The purpose of this study was to determine whether the loss of synapses represented a direct effect of ethanol on the density of spines (spines/nm) on the dendritic segments or an indirect effect of segment deletion. Spine densities on terminal dentrites were determined in Purkinje neurons from 40 old male Fischer 344 rats that were assigned randomly to one of three treatments groups, a chow-fed control group (n=8), an isocaloric and isovolumetric (pair-fed) control group (n=16), or an ethanol-fed group (n=16). Brain tissues were prepared by the Golgi-Cox procedure for light microscopy and coded to avoid investigator bias. 14 Purkinje neurons from each rat (a total of 560 cells) were randomly selected for quantitation of spines. In each neuron, spine counts and terminal segment lengths were determined for 14 paired and 14 umpaired terminal dendritic segments (a total of 15,680 measurements). Group averages tested by ANOVA showed no statistically significant decreases in spine density on spiny branchlets of Purkinje ne urons after chronic ethanol consumption. It was concluded that ethanol did not reduce the density of spines on dendritic segments of Purkinje neurons directly and that the decrease in synaptic density after ethanol treatment represented an indirect effect of segment deletion. (Funded by NIH/NIAAA grant AA05592) Keywords: Cerebellar Cortex, Ethanol, Golgi Cox, Purkinje Neurons, Synaptic Spine

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Unknown (K16)
Project #
5K16DE000158-14
Application #
6104538
Study Section
Project Start
1999-07-01
Project End
2000-06-30
Budget Start
1998-10-01
Budget End
1999-09-30
Support Year
14
Fiscal Year
1999
Total Cost
Indirect Cost
Name
State University of New York at Buffalo
Department
Type
DUNS #
038633251
City
Buffalo
State
NY
Country
United States
Zip Code
14260
Krebs, Linda J; Wang, Xiaopeng; Nagy, Atilla et al. (2002) Bombesin and epidermal growth factor potentiate the effect of cytotoxic LH-RH analog AN-152 in vitro. Int J Oncol 21:1325-9
Krebs, Linda J; Wang, Xiaopeng; Nagy, Attila et al. (2002) A conjugate of doxorubicin and an analog of Luteinizing Hormone-Releasing Hormone shows increased efficacy against oral and laryngeal cancers. Oral Oncol 38:657-663
Rogers, J D; Scannapieco, F A (2001) RegG, a CcpA homolog, participates in regulation of amylase-binding protein A gene (abpA) expression in Streptococcus gordonii. J Bacteriol 183:3521-5
Krebs, L J; Wang, X; Pudavar, H E et al. (2000) Regulation of targeted chemotherapy with cytotoxic lutenizing hormone-releasing hormone analogue by epidermal growth factor. Cancer Res 60:4194-9
Malek, R; Fisher, J G; Caleca, A et al. (1994) Inactivation of the Porphyromonas gingivalis fimA gene blocks periodontal damage in gnotobiotic rats. J Bacteriol 176:1052-9
Dolce, C; Anguita, J; Brinkley, L et al. (1994) Effects of sialoadenectomy and exogenous EGF on molar drift and orthodontic tooth movement in rats. Am J Physiol 266:E731-8
Stephan, E B; Dziak, R (1994) Effects of genistein, tyrphostin, and pertussis toxin on EGF-induced mitogenesis in primary culture and clonal osteoblastic cells. Calcif Tissue Int 54:409-13
Grossi, S G; Zambon, J J; Ho, A W et al. (1994) Assessment of risk for periodontal disease. I. Risk indicators for attachment loss. J Periodontol 65:260-7
Winston, J L; Chen, C K; Neiders, M E et al. (1993) Membrane protein expression by Actinobacillus actinomycetemcomitans in response to iron availability. J Dent Res 72:1366-73
Sharma, A; Sojar, H T; Lee, J Y et al. (1993) Expression of a functional Porphyromonas gingivalis fimbrillin polypeptide in Escherichia coli: purification, physicochemical and immunochemical characterization, and binding characteristics. Infect Immun 61:3570-3

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