Regulation of cell survival in the developing thalamus: an in vitro analysis.
There is evidence that developing thalamic cells become dependent for their survival on the integrity of their afferent and/or efferent connections, which may provide required levels of neural activity and/or essential neurotrophic factors. These connections develop in the second half of gestation in mice and, during this time (embryonic days 17-19), isolated thalamic cells either grown as explants or dissociated from each other lose their ability to survive. Here we show that the loss of viability of explants, but not of dissociated cells, is delayed if the cultures are treated with depolarizing stimuli. The survival of dissociated thalamic cells is promoted by culture medium conditioned by thalamic explants grown with depolarizing stimuli, indicating that the effect of depolarization involves trophic factors released by thalamic cells. This survival promoting effect is found prenatally, but not postnatally, and is prevented by the neurotrophin blocker K252a. Culture medium conditioned by cortex also promotes the survival of thalamic cells and this effect does occur postnatally. These findings suggest that diffusible factors, possibly members of the neurotrophin family, and depolarizing stimuli regulate thalamic cell survival before birth, but trophic support from cortex becomes crucial after birth. This culture model may provide a means of investigating the mechanisms of thalamic cell survival during development.
Asavaritikrai
Pundit
P
Genes and Development Research Group, Biomedical Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK.
Lotto
Beau
B
Anderson
Gillian
G
Price
David J
DJ
D000818:Animals; D002227:Carbazoles / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D017077:Culture Media, Conditioned / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005865:Gestational Age; D018698:Glutamic Acid / Q000494:pharmacology; D020287:In Situ Nick-End Labeling; D026121:Indole Alkaloids; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D009414:Nerve Growth Factors / Q000037:antagonists & inhibitors / Q000502:physiology; D011188:Potassium / Q000494:pharmacology; D013788:Thalamus / Q000166:cytology* / Q000187:drug effects / Q000196:embryology
D002227:Carbazoles; D017077:Culture Media, Conditioned; D004791:Enzyme Inhibitors; D026121:Indole Alkaloids; D009414:Nerve Growth Factors; D018698:Glutamic Acid; C049985:staurosporine aglycone; D011188:Potassium