Cholinergin innervation of the primate hippocampal formation. I. Distribution of choline acetyltransferasse immunoreactivity in the Macaca fascicularis and Macaca mulatta monkeys

Abstract

The cholinergic innervation of the hippocampal formation of Macaca fascicularis (cynomolgus) and Macaca mulatta (rhesus) monkeys was investigated by immunohistochemical procedures using a monoclonal antibody directed against choline acetyltransferase. The distribution of choline acetyltransferase in the monkey demonstrated both similarities and differences with the staining patterns observed in the rat or with acetylcholinesterase in the monkey. While both of these latter preparations demonstrated labeled cells, for example, no choline acetyltransferase labeled neurons were observed in the monkey hippocampal formation. Choline acetyltransferase activity was restricted to fibers which varied in thickness and number of varicosities and in their regional and laminar distribution. The highest densities of labeled fibers were observed in the uncal portion of the hippocampus, in the parasubiculum, and in the entorhinal cortex; the lowest densities of labeled fibers were observed in CA1 and in midrostrocaudal levels of the dentate gyrus. In the dentate gyrus, immunoreactive fibers were densely distributed in the molecular layer and in an infragranular plexus. One of the few striking noticeable interspecies differences was observed in the dentate gyrus. In the rhesus monkey, labeled fibers in the molecular layer were divided into a superficial denser and an inner lighter lamina, whereas in M. fascicularis, the cholinergic fibers were distributed more homogeneously throughout the molecular layer. In the hippocampus proper, there was a progressive decrease in the density of ChAT-immunoreactive fibers from CA3/CA2 into CA1. The subiculum also demonstrated modest labeling which was nonetheless higher than in CA1; the border of these fields demonstrated increased fiber labeling. The density of choline acetyltransferase staining was high in the presubiculum and parasubiculum. In the entorhinal cortex, a relatively clear boundary was observed between the more heavily stained superficial layers (I, II, and III) and the more weakly labeled deep layers (V and VI), especially in the intermediate and caudal fields. A transverse decreasing gradient was observed with the densest plexus of cholinergic fibers found in the medially situated olfactory field of the entorhinal cortex and the lowest density in the laterally located caudal and lateral fields.

The Primate Thalamus Is a Key Target for Brain Dopamine

“…Some sections were processed following a double-bridging procedure by returning them to the secondary antiserum solution for 1 h after the incubation in PAP and then again to the PAP complex for 90 min. After this, the sections were developed, mounted, and intensified by immersion in aqueous solutions of 0.005% osmium tetroxide and 0.05% thiocarbohydrazide (Alonso and Amaral, 1995). DAT was revealed in monkey tissue using a standard DAB protocol (0.05% DAB and 0.003% H 2 O 2 ).…”

Distribution of choline acetyltransferase-immunoreactive structures in the lamprey brain

“…This result also may represent a synapomorphy, because lampreys, diverse teleosts, and amphibians uniformly lack ChAT-ir cells in pallial areas (Ekström, 1987;Brantley and Bass, 1988;Marín et al, 1997;Adrio et al, 2000;Pérez et al, 2000). Even in amniotes the presence of cortical cholinergic neurons seems to be a characteristic acquired relatively late during evolution and certainly is not a feature shared by all species (Vincent and Reiner, 1987;Reiner, 1991;Medina et al, 1993;Medina and Reiner, 1994;Alonso and Amaral, 1995).…”

Comparative Analysis of the Organization of the Cholinergic System in the Brains of Two Holostean Fishes, the Florida Gar <b><i>Lepisosteus platyrhincus</i></b> and the Bowfin <b><i>Amia calva</i></b>

“…Studies of birds and reptiles have revealed the lack of cholinergic cells in cortical regions Brauth et al, 1985;Hoogland and Vermeulen-Van der Zee, 1990;Powers and Reiner, 1993;Medina and Reiner, 1994], with the lone exception of the lizard Gallotia gallotia [Medina et al, 1993]. In mammals, cholinergic cells were detected in the cortex of rats [Houser et al, 1985;Ichikawa and Hirata, 1986;Parnavelas et al, 1986;Ichikawa et al, 1997] and mice [Mufson and Cunningham, 1988;Consonni et al, 2009] but not in dogs, cats, guinea pigs, some rodents, monotremes [Kimura et al, 1981;Vincent and Reiner, 1987;Maley et al, 1988;St-Jacques et al, 1996;Manger et al, 2002;Bhagwandin et al, 2006] and adult primates, including humans Satoh and Fibiger, 1985;Mesulam and Geula, 1988;Geula et al, 1993;Alonso and Amaral, 1995]. Therefore, the presence of cholinergic cells in the pallium/cortex of vertebrates seems to be a variable feature that appears several times in evolution.…”