Neurotrophin receptor proteins immunoreactivity in the rat cerebellar cortex as a function of age.
The influence of age on immunohistochemically demonstrable neurotrophin receptor proteins (p75, trkA-, trkB-, and trkC-proteins) was studied in the cerebellar cortex of Wistar male rats aged 3 (young), 12 (adult) and 24 (old) months. The number of Purkinje neurons displaying p75, trkA- and trkC-like proteins immunoreactivity (IR), as well as the intensity of p75 and trkA-like protein IR, were significantly reduced in aged rats in comparison with 3 and 12-month-old rats. The intensity of trkC-like protein in the cytoplasm of Purkinje neurons remained unchanged for all the period studied. Moreover, no significant age-dependent changes were observed in the density of p75 or trkC-like proteins IR in the granule neurons layer. The molecular layer showed faint p75 IR which decreased as a function of age. No immunolabelling for neuronal trkB-like proteins was observed, but trkB- and trkC-like proteins IR was found in non-neuronal cells. These results suggest that cerebellar cortex neurons are responsive to and/or dependent upon different neurotrophins. Moreover, the age-dependent impairment in the expression of some neurotrophin receptors in Purkinje neurons, but not in the granule neurons, lends support to a role for neurotrophins in cerebellar aging.
Departamento de Morfología y Biología Celular, Facultad de Medicina, Universidad de Oviedo, Spain.
J M
JM
Torres
F
F
Javier Naves
I
I
Esteban
M E
ME
Del Valle
J A
JA
Vega
D000367:Age Factors; D000375:Aging / Q000502:physiology*; D000818:Animals; D000906:Antibodies / Q000276:immunology; D002540:Cerebral Cortex / Q000276:immunology / Q000502:physiology*; D007150:Immunohistochemistry; D008297:Male; D011505:Protein-Tyrosine Kinases / Q000276:immunology*; D011506:Proteins / Q000276:immunology*; D051381:Rats; D017208:Rats, Wistar
D000906:Antibodies; D011506:Proteins; D011505:Protein-Tyrosine Kinases