title: Moniliform deformation of retinal ganglion cells by formaldehyde-based fixatives.
abstract: Protocols for characterizing cellular phenotypes commonly use chemical fixatives to preserve anatomical features, mechanically stabilize tissue, and stop physiological responses. Formaldehyde, diluted in either phosphate-buffered saline or phosphate buffer, has been widely used in studies of neurons, especially in conjunction with dyes and antibodies. However, previous studies have found that these fixatives induce the formation of bead-like varicosities in the dendrites and axons of brain and spinal cord neurons. We report here that these formaldehyde formulations can induce bead formation in the dendrites and axons of adult rat and rabbit retinal ganglion cells, and that retinal ganglion cells differ from hippocampal, cortical, cerebellar, and spinal cord neurons in that bead formation is not blocked by glutamate receptor antagonists, a voltage-gated Na(+) channel toxin, extracellular Ca(2+) ion exclusion, or temperature shifts. Moreover, we describe a modification of formaldehyde-based fixatives that prevents bead formation in retinal ganglion cells visualized by green fluorescent protein expression and by immunohistochemistry.
authors.affiliation: Department of Neurobiology, Physiology and Behavior, University of California, Davis, California, 95616.
authors.forename: Tyler W
authors.initials: TW
authors.lastname: Stradleigh
authors.forename: Kenneth P
authors.initials: KP
authors.lastname: Greenberg
authors.forename: Gloria J
authors.initials: GJ
authors.lastname: Partida
authors.forename: Aaron
authors.initials: A
authors.lastname: Pham
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Ishida
mesh_terms: D000818:Animals; D016477:Artifacts; D002118:Calcium / Q000172:deficiency; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005404:Fixatives; D005557:Formaldehyde; D018014:Gene Transfer Techniques; D049452:Green Fluorescent Proteins / Q000235:genetics; D007150:Immunohistochemistry; D018613:Microscopy, Confocal; D016900:Neurofilament Proteins / Q000378:metabolism; D009994:Osmolar Concentration; D011817:Rabbits; D012165:Retinal Ganglion Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D017299:Rod Opsins / Q000378:metabolism; D012964:Sodium / Q000172:deficiency; D013779:Tetrodotoxin / Q000494:pharmacology; D059008:Time-Lapse Imaging; D046509:Tissue Culture Techniques; D000099210:Melanopsin
chemical_list: D002118:Calcium; D018691:Excitatory Amino Acid Antagonists; D005404:Fixatives; D005557:Formaldehyde; D049452:Green Fluorescent Proteins; D016900:Neurofilament Proteins; D017299:Rod Opsins; D012964:Sodium; D013779:Tetrodotoxin; D000099210:Melanopsin; C485184:enhanced green fluorescent protein; C051774:neurofilament protein H
keywords: RRID:AB_10049285 (antibody_DKaMSaf488); RRID:AB_10058149 (antibody_GFP); RRID:AB_10562716 (antibody_DKaRBaf555); RRID:AB_1566483 (antibody_SMI32); RRID:AB_2156044 (antibody_melanopsin); RRID:NIF-0000-30467(software_ImageJ); RRID:NLX_143660 (database_JCNantibody); RRID:RGD_60991 (organism_LErat); axons; dendrites; paraformaldehyde; retina; sucrose; varicosities