The Harderian gland of the northern grasshopper mouse,Onychomys leucogaster

Abstract

The Harderian gland of the northern grasshopper mouse, Onychomys leucogaster, consists of glandular tubuloalveolar endpieces with secretory cells (small- and large-droplet cells) surrounding a wide lumen. Lumina from adjacent endpieces join repeatedly, forming progressively wider channels. Ultimately, a single secretory duct opens at the anterior canthus of the eye. Abundant sudanophilic materials secreted into the lumina of the tubuloalveoli drain into the orbit of the eye. The presence of amber–brown concretions in, and the intense fluorescence of, the Harderian gland suggest that in O. leucogaster the secretory materials also include porphyrins. Fluorescence of these secretions demonstrates that they drain from the orbit into the nasal passages; grooming spreads these materials from the nares onto other parts of the body. Although the Harderian gland of O. leucogaster shows no sexual dimorphism, there are age-related changes. Small-droplet cells are present at 1 week of age and large-droplet cells appear by 2 weeks. By 4 weeks the gland is comparable to that of adults. Glands of a few adults exhibit two features rarely reported in other rodents: (1) clusters of degenerated tubules characterized by a loss of the secretory epithelium and (2) large aggregations of lymphoid cells.

Alligator tears: A reevaluation of the lacrimal apparatus of the crocodilians

“…This is based on the presence of interstitial lymphatic tissue (see Burns, 1992, for review) and numerous immunological studies (Burns, 1992;Montgomery and Maslin, 1992). Numerous studies have also described the presence of either lymphatic tissue (Krause and McMenamin, 1992;Tolivia et al, 1992;Bodyak and Stepanova, 1994;Coulson and Pinter, 1996;Sabry et al, 2000) or scattered plasma cells and lymphocytes (Sinha and Calhoun, 1966;Aitken and Survashe, 1977;Payne et al, 1982;Martin et al, 1988;Djeridane, 1992Djeridane, , 1994Djeridane, , 1996Antolín-Gonzá lez et al, 1993;Shirama et al, 1997;Aldana et al, 2002;Izci et al, 2002, Kumar et al, 2003Paulsen, 2003) in the mammalian Harderian gland. Thus, the presence of interstitial plasma cells and lymphocytes in alligators is not unusual, although the organization of the lymphatic tissue is unique.…”

Septomaxilla of nonmammalian synapsids: Soft-tissue correlates and a new functional interpretation

“…3) may simply reflect this realignment, in concert with the origin of Flehmen behavior (the presence of a nasopalatine duct in nonmammalian cynodonts suggests that some aspects of this process may have originated earlier). However, although the nasolacrimal fluids are known to be a component of the moisture on the rhinarium (Thiessen, 1992;Coulson and Pinter, 1996), there are currently no empirical data to indicate specifically that either Harderian gland secretions or other fluids in the nasolacrimal duct are implicated in the collection of VNO-sensitive odor samples in mammals.…”

“…The function of the Harderian gland has been studied in rodents, but is, unfortunately, unknown in other mammals. In rodents, Harderian gland secretions are implicated in pheromone secretion (Harriman and Thiessen, 1985;Thiessen and Harriman, 1986;Coulson and Pinter, 1996), photoreception (Wetterberg et al, 1970a,b;Reiter and Klein, 1971;Pevet et al, 1984), and thermoregulation (Thiessen, 1977;Thiessen and Kittrell, 1980;Harlow, 1984;Pevet et al, 1984;see Olcese andWesche, 1989, andThiessen, 1992, for reviews). The secretions are released first onto the cornea, and are subsequently drained through the nasolacrimal duct and delivered to the rostrum.…”

“…The secretions are released first onto the cornea, and are subsequently drained through the nasolacrimal duct and delivered to the rostrum. During self-grooming episodes, Harderian gland lipids are spread across the fur, in a manner analogous to the preening behavior of birds (Thiessen, 1977(Thiessen, , 1992Coulson and Pinter, 1996). The Harderian gland secretions coat the fur and, like the avian preening oils, provide a lipid barrier to cold and wetness and alter the reflectance quality of the pelage (Thiessen, 1977(Thiessen, , 1992Thiessen and Kittrell, 1980;Harlow, 1984).…”

“…Harderian lipids also reduce cutaneous water loss (Harriman and Thiessen, 1983;Harlow, 1984). Furthermore, Harderian gland exudates are thought to contain pheromones that affect intraspecific interactions, such as female proceptive behavior, intermale aggression, and parent/offspring interactions (Olcese and Wesche, 1989;Thiessen, 1992;Coulson and Pinter, 1996). The rodent Harderian gland has not been implicated in VNO function.…”