Laminin and a basement membrane extract have different effects on axonal and dendritic outgrowth from embryonic rat sympathetic neurons in vitro

• Published in: Developmental biology Vol. 136; no. 2; pp. 330 - 345
• Main Authors: Lein, Pamela J., Higgins, Dennis
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.12.1989; Elsevier
• Subjects: Animals; Axons - ultrastructure; Basement Membrane - physiology; Biological and medical sciences; Cell Differentiation - drug effects; Culture Techniques; Dendrites - ultrastructure; Dose-Response Relationship, Drug; Embryology: invertebrates and vertebrates. Teratology; Experimental organogenesis; Fundamental and applied biological sciences. Psychology; Ganglia, Sympathetic - cytology; Ganglia, Sympathetic - metabolism; Laminin - pharmacology; Norepinephrine - metabolism; Organogenesis. Physiological fonctions; Polylysine - pharmacology; Rats; RNA - metabolism; Embryonic development; Rat; Growth; Rodentia; Tissue culture; Axon; In vitro; Dendrite; Vertebrata; Mammalia; Laminin; Neuron; Morphology; Extracellular matrix; Nerve fiber; Sympathic nervous system
• DOI: 10.1016/0012-1606(89)90260-1
• ISSN: 0012-1606

We have characterized the effects of laminin and a basement membrane extract (BME) on the morphology of embryonic rat sympathetic neurons maintained in tissue culture in the absence of nonneuronal cells. Neurons were grown on polylysine-coated coverslips in the presence or absence of laminin or BME in serum-free medium. Axons were distinguished from dendrites using intracellular dye injections, immunocytochemistry, and [ 3H]uridine autoradiography. In short-term (⩽24 hr) culture, laminin had a potent neurite-promoting effect, causing increases in the number of processes, total neuritic length, and neuritic branching. In long-term (3–35 days) cultures chronically exposed to laminin, most (>75%) neurons maintained supernumerary axons but failed to form dendrites. In contrast, most neurons (>70%) grown in long-term culture on polylysine in the absence of laminin were unipolar, extending a single axon. BME caused sympathetic neurons to extend multiple (range, 1–15) dendrites. Morphometric measurements made after 1 month of exposure to BME indicated that the amount of dendritic growth that occurred in vitro was similar to that normally occurring during a comparable period in situ. BME did not cause changes in the number of axons per neuron or in the uptake of neurotransmitter. Preliminary characterization of the dendrite-promoting activity of BME suggests that it resides in extracellular matrix (ECM) molecules and not in low-molecular weight contaminants. These observations indicate that (1) axonal and dendritic growth may be differentially regulated by various constituents of the ECM, and (2) such process-specific interactions can significantly affect the morphological development of sympathetic neurons.