4 research outputs found
Retinal afferents on Golgi-identified vertical neurons in the superior colliculus of the rabbit. A Golgi-EM,
The characteristics and distribution pattem of
retinal afferent terminals making synaptic contacts on
narrow field vertical neurons in the stratum griseum
superficiale of the rabbit superior colliculus were studied
using the Golgi-gold substitution technique in
combination with either autoradiographic or
degenerative methods. At the level of light microscopy,
identified gold-toned vertical neurons showed similar
features to those previously described by others.
Although their axons were frequently seen rising from
the basal dendritic tuft, they could also emerge from an
apical dendrite, but rarely from the cell body. The
electron rnicroscopic study revealed that these neurons
received radiolabelled or degenerated profiles with
typical features of retinal terminals, while more proximal
parts seemed to receive fewer terminals but of larger
size. Axo-somatic synaptic junctions were very rare and,
interestingly, retinal terminals were not seen forming
synapses on the basal dendritic arborization. The present
results indicate that the narrow field vertical cells are
targets for retinotectal projection
Distribution of cortico-visual neurons projecting to the pons in the cat. A retrograde labelling study with rhodamine latex microspheres
Injections of the low diffusion retrograde
tracer rhodamine latex microspheres were made in the
pontine grey matter of the cat in order to study the
cortical convergence to the pons. We found a different
distribution of cells in the convex surface of the brain
hemisphere making ventral os dorsolateral injections. In
the first case, cells were grouped in the top of the gyri. In
the second case, cells were more frequent in the bottom
of the sulci. Our results show a possible retinotopic
organization of this projection
Immunocytochemical localization of metabotropic (mGluR2/3 and mGluR4a) and ionotropic (GluR2/3) glutamate receptors in adrenal medullary ganglion cells
The localization of metabotropic glutamate
receptors of groups II (mGluR2/3) and III (mGluR4a)
and the subunits 2 and 3 of alfa-amino-3-hydroxy-5-
methyl-4-isoxazolepropionic acid (AMPA) ionotropic
glutamate receptors (GluR2/3) was investigated with
immunocytochemical methods in the rat adrenal gland.
MGluR2/3, mGluR4a and GluR2/3 immunoreactivities
were observed in large-sized, centrally located type I
adrenal medullary ganglion neurons. Furthermore, the
small-sized type II adrenal ganglion neurons identified
by their immunoreactivity to brain nitric oxide synthase
(bNOS), also expressed mGluR2/3, mGluR4a and
GluR2/3. These cells were disposed in the peripheral
portion of the adrenal medulla. None of the type I
neurons were positively labeled for bNOS. These
morphological observations suggest that activation of
glutamate receptors in ganglion neurons may be
instrumental in the control of adrenal endocrine systems
as well as blood regulation