Immunohistochemical mapping of neuropeptide Y in the tree shrew brain

Abstract

Day-active tree shrews are promising animals as research models for a variety of human disorders. Neuropeptide Y (NPY) modulates many behaviors in vertebrates. Here we examined the distribution of NPY in the brain of tree shrews (Tupaia belangeri chinensis) using immunohistochemical techniques. The differential distribution of NPY-immunoreactive (-ir) cells and fibers were observed in the rhinencephalon, telencephalon, diencephalon, mesencephalon, metencephalon, and myelencephalon of tree shrews. Most NPY-ir cells were multipolar or bipolar in shape with triangular, fusiform, and/or globular perikarya. The densest cluster of NPY-ir cells were found in the mitral cell layer of the main olfactory bulb (MOB), arcuate nucleus of the hypothalamus, and pretectal nucleus of the thalamus. The MOB presented a unique pattern of NPY immunoreactivity. Laminar distribution of NPY-ir cells was observed in the MOB, neocortex, and hippocampus. Compared to rats, the tree shrews exhibited a particularly robust and widespread distribution of NPY-ir cells in the MOB, bed nucleus of the stria terminalis, and amygdala as well as the ventral lateral geniculate nucleus and pretectal nucleus of the thalamus. By contrast, a low density of neurons were scattered in the striatum, neocortex, polymorph cell layer of the dentate gyrus, superior colliculus, inferior colliculus, and dorsal tegmental nucleus. These findings provide the first detailed mapping of NPY immunoreactivity in the tree shrew brain and demonstrate species differences in the distribution of this neuropeptide, providing an anatomical basis for the participation of the NPY system in the regulation of numerous physiological and behavioral processes.

Herpes Simplex Virus 1 Infection of Tree Shrews Differs from That of Mice in the Severity of Acute Infection and Viral Transcription in the Peripheral Nervous System

“…Rodent models are seldom used for chronic stress paradigms of human disease, whereas tree shrews are (43)(44)(45). Furthermore, tree shrews are finding a place in many models of human brain pathogenesis from mapping of neuropeptide distribution (46), models for opiate addiction (47) to drug target mining (48) and specific diseases such as Parkinson's disease (49). HSV infection was first reported in the tree shrew in 1978 by Darai et al, who studied the pathogenesis following intravenous, intraperitoneal, and subcutaneous infection (27).…”

创制动物模型,为何不用树鼩呢?

“…The recent studies of the presence and distribution of neuropeptides in tree shrew brain and comparative analyses with other species (Ni et al, 2014, 2015; Petruzziello et al, 2012) has laid the biochemical basis for us to learn more about the specific and common features of tree shrew brain. It is very important to highlight all of these diverse and interesting aspects of the tree shrew, in order to promote the acceptance of this animal more widely in neurobehavioral studies.…”

Distribution of corticotropin-releasing factor in the tree shrew brain

“…Designation of neuroanatomical structures is based on the published atlas for tree shrews (Marrocco et al, 1970;Ni et al, 2014Ni et al, , 2015Yang et al, 1990) and the Paxinos brain atlases of rat and monkey (Paxinos et al, 1999;Paxinos and Watson, 2006). Light microscopic images were captured using an Axiocam HRc digital microscope camera (Carl Zeiss).…”

“…The relative density of labeling was classified as absent (0), sparse (1), moderate (2), and dense (3) as described previously (Ni et al, 2015). The degree of CRF immunostaining was assessed by the same observer blind to the experimental condition of each animal.…”

“…In addition, the tree shrew is a (footnote continued) division; CA1, field CA1 of the hippocampus; CA2, field CA2 of the hippocampus; CA3, field CA3 of the hippocampus; b r a i n r e s e a r c h 1 6 1 8 ( 2 0 1 5 ) 2 7 0 -2 8 5 day-active species closely related to primates and thus may be a valuable model species for studies of sleep behavior in humans (Coolen et al, 2012). Moreover, immunohistochemical mapping of several neuropeptides has been clearly drawn in the tree shrew brain (Ni et al, 2014(Ni et al, , 2015. Only a small number of CRF-ir cells were observed in the PVN but not in the BST and CeA in control or stressed tree shrews (Kozicz et al, 2008).…”