PT  - JOURNAL ARTICLE
AU  - L McKerracher
AU  - C Essagian
AU  - AJ Aguayo
TI  - Marked increase in beta-tubulin mRNA expression during regeneration of axotomized retinal ganglion cells in adult mammals
AID  - 10.1523/JNEUROSCI.13-12-05294.1993
DP  - 1993 Dec 01
TA  - The Journal of Neuroscience
PG  - 5294--5300
VI  - 13
IP  - 12
4099  - http://www.jneurosci.org/content/13/12/5294.short
4100  - http://www.jneurosci.org/content/13/12/5294.full
SO  - J. Neurosci.1993 Dec 01; 13
AB  - Changes in gene expression were investigated in axotomized CNS neurons under conditions that inhibit or permit regrowth of their damaged axons. Levels of mRNA encoding beta-tubulin, the 150 kDa neurofilament subunit (NF-M), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were examined by quantitative in situ hybridization of adult rat retinal ganglion cells (RGCs) after axotomy in the optic nerve or during regeneration in a peripheral nerve (PN) graft. Soon after optic nerve section beta-tubulin, NF-M, and GAPDH mRNA levels decreased and remained low during the 1 month studied. In these retinas beta-tubulin mRNA fell to approximately 50% of normal controls. However, in the PN- grafted retinas, where approximately 20% of the surviving axotomized RGCs regenerate their axons, there were “hot spots” of beta-tubulin mRNAs where neuronal levels were nearly 300% higher than in controls. By retrograde neuronal labeling these hot spots were shown to correspond to the injured RGCs that regrew their axons into the PN graft; beta-tubulin mRNA levels in nonregenerating RGCs of the same retinas averaged 63% of controls. We suggest that interactions of RBC axons and components of the grafts' non-neuronal environment play a key role in the over fourfold differences in beta-tubulin mRNA levels observed between injured and regenerating RGCs.