TY - JOUR
T1 - All amacrine neurons of the rat retina show diurnal and circadian rhythms of parvalbumin immunoreactivity
AU - Gábriel, Robert
AU - Lesauter, Joseph
AU - Bánvölgyi, Tamás
AU - Petrovics, György
AU - Silver, Rae
AU - Witkovsky, Paul
N1 - Funding Information:
This study was supported by an OTKA grant (T 34160), NIH grants NS 37919 (R.S.) and ET 03570, NSF grant IBN-96418886 (R.S.), and grants from the Helen Hoffritz Charitable Trust and Research to Prevent Blindness, Inc. R.G. was also in receipt of a J nos Bolyai fellowship
PY - 2004/2
Y1 - 2004/2
N2 - We investigated parvalbumin immunoreactivity (PA-IR) in the retinas of rats maintained on a 12:12 h light:dark cycle, or after being placed in constant darkness for 24-72 h. Retinas were harvested at zeitgeber and circadian times 02:00, 06:00, 10:00, 14:00, 18:00 and 22:00 h. PA-IR was found primarily in retinal amacrine cells of the AII subtype. In a light/dark cycle, PA-IR showed a clear rhythm, with a low near zeitgeber time (ZT) 10:00 h and a peak near ZT 18:00 h. The ratio of immunofluorescence intensities at these timepoints was >15-fold. When animals were kept in complete darkness for 1-3 days, the rhythm of PA-IR was still preserved, but was progressively reduced in amplitude. The rhythm of PA-IR inferred from immunohistochemical data was confirmed by Western blots. We conclude that PA-IR in the rat retina shows an underlying circadian rhythm that is enhanced by cyclic light. The regulation may involve translocation of the protein between cell compartments and/or new protein synthesis.
AB - We investigated parvalbumin immunoreactivity (PA-IR) in the retinas of rats maintained on a 12:12 h light:dark cycle, or after being placed in constant darkness for 24-72 h. Retinas were harvested at zeitgeber and circadian times 02:00, 06:00, 10:00, 14:00, 18:00 and 22:00 h. PA-IR was found primarily in retinal amacrine cells of the AII subtype. In a light/dark cycle, PA-IR showed a clear rhythm, with a low near zeitgeber time (ZT) 10:00 h and a peak near ZT 18:00 h. The ratio of immunofluorescence intensities at these timepoints was >15-fold. When animals were kept in complete darkness for 1-3 days, the rhythm of PA-IR was still preserved, but was progressively reduced in amplitude. The rhythm of PA-IR inferred from immunohistochemical data was confirmed by Western blots. We conclude that PA-IR in the rat retina shows an underlying circadian rhythm that is enhanced by cyclic light. The regulation may involve translocation of the protein between cell compartments and/or new protein synthesis.
KW - Calcium-binding proteins
KW - Immunocytochemistry
KW - Inner plexiform layer
KW - Rat
KW - Western blots
UR - http://www.scopus.com/inward/record.url?scp=2442643740&partnerID=8YFLogxK
U2 - 10.1007/s00441-003-0785-2
DO - 10.1007/s00441-003-0785-2
M3 - Article
C2 - 14610664
AN - SCOPUS:2442643740
SN - 0302-766X
VL - 315
SP - 181
EP - 186
JO - Cell and Tissue Research
JF - Cell and Tissue Research
IS - 2
ER -