Calcium binding proteins immunohistochemistry and identification of neurons in the mammalian pineal gland of the African giant rat: Cricetomys gambianus
E. Bastianelli et al., Calcium binding proteins immunohistochemistry and identification of neurons in the mammalian pineal gland of the African giant rat: Cricetomys gambianus, GEN PHYSL B, 18(1), 1999, pp. 5-17
The presence of true neurons in the rodent pineal gland is still a matter o
f controversy. In this work, by using immunohistochemistry with five antibo
dies against calcium-binding proteins (calbindin-D28k, calretinin, calmodul
in, neurocalcin and S-100 beta) and Cricetomys gambianus, a rodent belongin
g to Muridae family living in Africa, we were able to illustrate the presen
ce of neurons in the pineal gland. Anti-calbindin-D28k and anti-calretinin
labelled neurons belonging to two neural ganglia. One ganglion was localize
d in the anterior part of the gland near the pineal stalk and the other one
in the posterior portion of the organ. Immunoreactive neurons are medium i
n size (15-20 mu m) and have long thick processes running towards the stalk
. Calretinin and calbindin-D28k positive neurons stained with different int
ensities. Thin processes were detected by anti-calretinin whereas thick pro
cesses were preferentially calbindin-D28k positive. Neurocalcin labelled a
few smaller neurons and many thin processes within the ganglion. Calmodulin
could not be detected immunochemically. Within the ganglia many astrocytic
processes were S-100 beta positive. The afferent and the efferent pathways
of the pineal ganglia remain to be elucidated.