Pedunculopontine nucleus (PPN) is a brainstem
nucleus with an obscure border and located in the caudal
tegmentum. In recent years, the numbers of studies related to PPN
have been increasing due to its role in sleep/waking, in behavior,
learning, and attention as well as its role in generation and control
of locomotion. Besides cholinergic neurons, there are GABAergic,
glutamatergic, dopaminergic and noradrenergic neurons in the
PPN. Recently, the PPN has been a target for treatment of axial
semptoms in Parkinson disease (PD). Calbindin, a member of the
calcium binding protein family, which is an important molecule
during protein synthesis has been related to neurodegenerative
diseases. In our study, we investigated the developmental
differences of calbindin expression which is related to GABAergic
and glutamatergic neurons.
Materials and Methods: The borders of the PPN were
determined on the basis of the distribution of cholinergic neurons.
Calbindin is expressed by GABAergic and glutamatergic neurons.
Wistar rats aged 7, 14 and 21 days were perfused through the heart
with a 4% paraformaldehyde solution. Brains were removed and 40
μm plane of sections were cut via microtome. Free-floating slices
were stained with anti choline asetyltransferase and calbindin. In
our study, we used 4 rats for each group, totally 12 rats were
utilized. The number, location and diameters of calbindin positive
neurons in PPN were evaluated in 7, 14 and 21 day-old rats.
Results: The mean numbers of neurons were 30 ±3 at 7 days,
11 ±1 at 14 days and 150±50 at 21 days rats. There were
statistically significant differences between 7 and 14 days and 14
and 21 day-old rats (p=0.0075 ve p=0.0343 respectively). The
diameters of the neurons were 13 ±1.4 μm at 7 days, 11±1.6 μm at
14 days; 13.5±1.1μm at 21days.
Conclusion: This study indicates that critical developmental
changes in PPN occur between these intervals. These findings
support and contribute to the findings of previous studies.