Cochlear nucleusRevealing the molecular layer of the primate dorsal cochlear nucleus
Section snippets
Tissue procedure
Tissue from rhesus monkeys was obtained after transcardial perfusion at the Johns Hopkins Medical School, Baltimore, MD, USA, or the Emory Primate Center, Atlanta, GA, USA. At both institutions, animal protocols were approved by the institutional animal care and use committees and followed NIH guidelines. All experiments conformed to named local and international guidelines on the ethical use of animals. This research minimized the number of animals used and their suffering.
Three rhesus monkeys
Granule cells and PFs in the primate DCN
Nissl staining was used to determine whether the primate DCN had a laminar organization. Coronal sections revealed a layered organization in the rhesus DCN (Fig. 1A). There was a superficial or molecular layer (layer I) with scattered small nuclei and a deeper region (layers II and III) with abundant nuclei of different shapes and sizes (8–20 µm). Large elongated cell bodies of fusiform cells (20 µm in size) were clearly observed distributed in layer II and formed a discrete but distinguishable
Discussion
By using electron microscopy and immunohistochemistry at the light and electron microscopic level we observed that the organization of the primate DCN is similar to that of the nonprimate mammal. The finding of many unmyelinated thin axons and the characteristic en passant glutamatergic synapses on dendritic spines within the molecular layer strongly support these arguments. Furthermore, we showed that the primate DCN share the main molecular components of excitatory neurotransmission with
Acknowledgments
We acknowledge NIH/NIDCD RO1 DC006881 to M.E.R., RO1 DC004395 to D.K.R. and NSF DBI-0420580 for funds to purchase the Tecnai G2 Spirit Biotwin electron microscope. We thank D. Robert Wenthold for kindly providing the antibodies for GluR1, Glu2/3, GluR4 and delta [1/2]. Antibodies directed against PDF10A were generously provided by Pfizer, Inc.
References (64)
- et al.
Calcium-binding proteins in the nervous system
Trends Neurosci
(1992) - et al.
Localization of VGLUT3, the vesicular glutamate transporter type 3, in the rat brain
Neuroscience
(2004) - et al.
Purkinje-like cells in rat cochlear nucleus
Hear Res
(1994) - et al.
Specific plasticity responses to unilaterally decreased or increased hearing intensity in the adult cochlear nucleus and beyond
Hear Res
(2006) - et al.
Tinnitus as a plastic phenomenon and its possible neural underpinnings in the dorsal cochlear nucleus
Hear Res
(2005) Role of the dorsal cochlear nucleus in the sound localization behaviour of cats
Hear Res
(2000)Redistribution of synaptic AMPA receptors at glutamatergic synapses in the dorsal cochlear nucleus as an early response to cochlear ablation in the rat
Hear Res
(2006)- et al.
Glutamate receptors are selectively targeted to postsynaptic sites in neurons
Neuron
(1997) - et al.
Immunohistochemical localization of PDE10A in the rat brain
Brain Res
(2003) - et al.
Glycine immunoreactive projections from the dorsal to the anteroventral cochlear nucleus
Hear Res
(1991)