Neuronal nitric oxide synthase immunopositive neurons in cat claustrum—a light and electron microscopic study

Abstract

Nitric oxide is a unique neurotransmitter, which participates in many physiological and pathological processes in the organism. Nevertheless there are little data about the neuronal Nitric Oxide Synthase immunoreactive (nNOS-ir) neurons and fibers in the dorsal claustrum (DC) of a cat. In this respect the aims of this study were: (1) to demonstrate nNOS-ir in the neurons and fibers of the DC; (2) to describe their light microscopic morphology and distribution; (3) to investigate and analyze the ultrastructure of the nNOS-ir neurons, fibers and synaptic terminals; (4) to verify whether the nNOS-ir neurons consist a specific subpopulation of claustral neurons; (5) to verify whether the nNOS-ir neurons have a specific pattern of organization throughout the DC. For demonstration of the nNOS-ir the Avidin-Biotin-Peroxidase Complex method was applied. Immunopositive for nNOS neurons and fibers were present in all parts of DC. On the light microscope level nNOS-ir neurons were different in shape and size. According to the latter they were divided into three groups-small (with diameter under 15 microm), medium-sized (with diameter from 16 to 20 microm) and large (with diameter over 21 microm). Some of nNOS-ir neurons were lightly-stained while others were darkly-stained. On the electron microscope level the immunoproduct was observed in neurons, dendrites and terminal boutons. Different types of nNOS-ir neurons differ according to their ultrastructural features. Three types of nNOS-ir synaptic boutons were found. As a conclusion we hope that the present study will contribute to a better understanding of the functioning of the DC in cat and that some of the data presented could be extrapolated to other mammals, including human.

Synaptic organization of striate cortex projections in the tree shrew: A comparison of the claustrum and dorsal thalamus

“…1L). As previously described for the cat claustrum (Rahman and Baizer, 2007;Hinova-Palova et al, 2008), antibodies against calretinin, neuronal nitric oxide synthase, and parvalbumin stain subpopulations of nonspiny cells within the claustrum (Fig. 1J-L), whereas the substance P antibody stains axon terminals (Fig.…”

“…In support of this, we found that presynaptic dendrites in the claustrum contain GABA. Many varieties of calcium‐binding proteins, neuropeptides, and enzymes are found within the nonspiny neurons of the claustrum (Druga et al, ; Hinova‐Palova et al, , , , ; Reynhout and Baizer, ; Rahman and Baizer, ; Baizer et al, ; Kim et al, ). We also found that cells in the tree shrew claustrum stained with antibodies against parvalbumin, neuronal nitric oxide synthase, or calretinin did not exhibit spines.…”

Topographical distribution and morphology of NADPH-diaphorase-stained neurons in the human claustrum

“…The investigations of our laboratory have been focused on the cytoarchitecture, ultrastructure, immunocytochemistry, and connections of the claustrum for over 30 years (Hinova-Palova et al, 1979, 1980a,b, 1988, 1997, 2001, 2007, 2008, 2012a,b; Hinova-Palova, 1981, 1986; Hinova-Palova and Usunoff, 1981; Hinova-Palova and Christova, 1988a,b; Hinova-Palova and Braak, 1993; Edelstein et al, 2011a,b, 2012a,b). The internal complexity and intricate cortical interrelationships of this broad and sheet-like telencephalic mass comes as no surprise, given its diverse neuronal composition and intrinsic functional heterogeneity.…”

The Claustrum in the Squirrel Monkey

“…For example, expression of calcium‐binding proteins defines subclasses of CLA neurons in several species including humans (Reynhout and Baizer, ; Real et al, ; Wójcik et al, ; Dávila et al, ; Hinova‐Palova et al, ; Rahman and Baizer, ; Kowianski et al, ; Hinova‐Palova et al, ; Druga et al, ; Pirone et al, ; Szalak et al, ). Other markers that define neurons in the CLA include nNOS, the synthetic enzyme for nitric oxide, and several peptides (Eiden et al, ; Hinova‐Palova et al, ; Kowiański et al, ; Kowianski et al, ; Hinova‐Palova et al, ; Landzhov et al, ). These data suggest that there are multiple neurochemically defined classes of interneurons; subclasses of projection neurons have not been similarly identified.…”