The spatial organization of olfactory receptor surfaces and odorant passageways within the nasal cavity was studied in hamsters through descriptive and morphometric analyses of a complete stereotaxically defined series of coronal, sagittal, and horizontal sections through the snout. These analyses reveal that the caudal two-thirds of each cavity is divided into two longitudinally oriented medial and lateral channels. The olfactory mucosa that lines these two channels projects selectively onto the medial and lateral halves of the main olfactory bulb (MOB), respectively. Moreover, the ethmoturbinates of the caudal recesses create highly convoluted channels, lined by ventrally projecting mucosa, that lie ventral, lateral, and dorsal to a relatively smooth central channel lined by dorsally projecting mucosa. The rhinotopic map makes equivalent representations of medial and lateral olfactory space to the MOB but gives the smooth space lined by dorsally projecting mucosa a disproportionately larger representation on the MOB than the convoluted space lined by the more expansive ventrally projecting mucosa. Recent descriptions of the spatial distribution of probes for odorant receptor proteins conform closely to this organization, giving credence to the idea that rhinotopy is a basis for representing to the MOB the specific molecular features of odorant molecules.

The spatial organization of projections from olfactory receptor neurons to the main olfactory bulb (MOB) was studied in hamsters by using fluorescent stilbene isothiocyanates as retrograde tracers. Injections confined to small sectors of the MOB produce labeling of receptor neurons that is more restricted circumferentially (i.e., with respect to the medial-lateral and dorsal-ventral axes) than longitudinally (i.e., with respect to the rostral-caudal axis) along the mucosal sheet. This restricted labeling is also discontinuous, giving an initial impression that the peripheral input is only crudely organized with respect to the medial-lateral and dorsal-ventral axes of the nasal cavity. However, from analyses of serial sections, it is apparent that each set of mucosal segments shares convergent projections to a circumferential quadrant of the MOB with other segments that are positioned around a common domain of the nasal cavity airspace. The primary afferent projections to the MOB, thus, are organized rhinotopically (i.e., with respect to the three-dimensional position of receptor neurons in olfactory space) rather than mucosotopically.

Aphrodisin, the major soluble protein in hamster vaginal discharge, is detected by receptors within the vomeronasal organ of the male hamster, and stimulates copulatory behavior. The loss of this effect on behavior after degradation of the protein with heat or proteolytic enzymes shows that the polypeptide chain is an essential part of the pheromone. Furthermore, attempts to remove small molecules from the protein have provided little indication of the presence of a transported ligand. However, the chemical and physical properties of the protein itself indicate that it could bind low molecular weight, water-insoluble compounds. The abundance, size, charge, and the primary structure of aphrodisin, when considered together, all indicate that it is a member of the recently recognized α-2u-globulin superfamily of extracellular proteins, some of which, such as serum retinol-binding protein and odorant-binding protein, are known to bind smaller molecules. Preliminary results from a study of the effects of bacterial aphrodisin, produced by molecular cloning in E.coli, on behavior indicate that the polypeptide backbone is only partially active and that post-translational modifications of the protein or the presence of an as yet undetected ligand may be necessary for full activity.

Three proteins related to the hamster vaginal discharge protein aphrodisin were purified, subjected to adsorption chromatography for removal of volatile compounds and tested for pheromonal activity in an assay of copulatory behavior exhibited by male hamsters toward a surrogate female. One of the proteins is conspecific to aphrodisin, it is the second most abundant protein in the vaginal discharge. Like aphrodisin it migrates as a relatively acidic protein in electrophoresis under non-denaturing conditions, and it appears to have an identical monomeric molecular mass (17 kd) in electrophoresis with 0.1% sodium dodecylsulfate. Heterospecific proteins included the female mouse major urinary protein (MUP) and β-lactoglobulin from cow's milk, which have some similarity in amino acid sequence to aphrodisin and belong to the α2u-globulin protein superfamily. In spite of these chemical relationships, neither the conspecific protein nor the heterospecific proteins had aphrodisiac activity comparable to that of aphrodisin in the surrogate female behavioral assay. The pheromonal activity of aphrodisin thus appears to be dependent on specific structural features of the protein.

Aphrodisin is a protein which is secreted in hamster vaginal discharge and acts via the vomeronasal organ of the accessory olfactory system to elicit copulatory behavior in male hamsters. The complete primary structure of aphrodisin was determined by sequence analysis of intact aphrodisin after unblocking the amino terminus with pyroglutamate aminopeptidase and from peptides generated by trypsin and Lys-C digests. Alignment of the peptides was obtained from sequence analysis of peptides from cyanogen bromide and hydroxylamine cleavages. The protein consists of 151 residues of Mr = 17,000. It has disulfide bonds linking cysteine residues at positions 38 and 42 and at 57 and 149. N-acetylglucosamine residues are linked to asparagines at positions 41 and 69. Based on its similarity to the major urinary proteins in rats and mice, aphrodisin is a putative member of the alpha 2u-globulin superfamily of extracellular proteins.

Female mouse urine contains a pheromone that acts via the vomeronasal organ of conspecific males to stimulate a rapid increase in circulating levels of luteinizing hormone. A bioassay based on this male response was used to test biochemical preparations of female urine. Retention of significant biological activity by the urine after dialysis indicated that the activity is associated with urinary protein. Complete loss of activity from the urine after adsorption chromatography on a neutral polystyrene column suggested that the protein functions as a pheromone carrier. Assay of gel permeation chromatography fractions, before and after degradation of the urinary proteins with proteolytic enzymes, demonstrated that the protein is not necessary for the male response in the bioassay. Its resistance to vigorous pro teolytic enzyme treatment further indicates that the pheromone is not a peptide. High biological activity, indistinguishable from that of the unfractionated urine, was isolated in a protein-depleted, presumably low molecular weight fraction containing compounds that are retarded by adsorption on Sephadex. The chemical properties of this female mouse pheromone are markedly different from those of a recently purified female hamster pheromone that also acts via the vomeronasal organ.

Annals of the New York Academy of SciencesVolume 519, Issue 1 p. 150-164 Hormones and Neurotransmitters in the Mammalian Olfactory Systema F. MACRIDES, F. MACRIDES Worcester Foundation for Experimental Biology Shrewsbury, Massachusetts 01545Search for more papers by this authorT. A. SCHOENFELD, T. A. SCHOENFELD Worcester Foundation for Experimental Biology Shrewsbury, Massachusetts 01545Search for more papers by this authorA. N. CLANCY, A. N. CLANCY Worcester Foundation for Experimental Biology Shrewsbury, Massachusetts 01545Search for more papers by this authorM. S. A. KUMAR, M. S. A. KUMAR Department of Anatomy and Cellular Biology, Tufts University School of Veterinary Medicine Boston, Massachusetts 02111Search for more papers by this authorR. M. KREAM, R. M. KREAM Anesthesia Research, Tufts University School of Medicine Boston, Massachusetts 02111Search for more papers by this author F. MACRIDES, F. MACRIDES Worcester Foundation for Experimental Biology Shrewsbury, Massachusetts 01545Search for more papers by this authorT. A. SCHOENFELD, T. A. SCHOENFELD Worcester Foundation for Experimental Biology Shrewsbury, Massachusetts 01545Search for more papers by this authorA. N. CLANCY, A. N. CLANCY Worcester Foundation for Experimental Biology Shrewsbury, Massachusetts 01545Search for more papers by this authorM. S. A. KUMAR, M. S. A. KUMAR Department of Anatomy and Cellular Biology, Tufts University School of Veterinary Medicine Boston, Massachusetts 02111Search for more papers by this authorR. M. KREAM, R. M. KREAM Anesthesia Research, Tufts University School of Medicine Boston, Massachusetts 02111Search for more papers by this author First published: December 1987 https://doi.org/10.1111/j.1749-6632.1987.tb36294.xCitations: 2 a This research was supported by the National Institute of Neurological and Communicative Disorders and Stroke (Grant NS12344) and the National Institute on Drug Abuse (Grant DA04128). AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume519, Issue1The Terminal Nerve (Nervus Terminalis): Structure, Function, and EvolutionDecember 1987Pages 150-164 RelatedInformation

The effects of castration and testosterone (T) replacement on levels of substance P (SP) and luteinizing hormone-releasing hormone (LHRH) were assessed in discrete areas of the male hamster brain. The animals were either castrated, castrated and given a chronically low or high dose of T by Silastic implant, or sham-operated. Brain tissues and trunk blood were collected 3 weeks after surgery. Plasma T levels were maintained within the normal range by the implants but at significantly lower or higher levels than the mean for sham-operated males. Levels of SP and LHRH were quantified in the olfactory bulbs, rostral basal forebrain, anterior hypothalamic and preoptic area, medial basal hypothalamic area, medial basal hypothalamic area and median eminence, and brain stem. In general, castration and T replacement effected opposite changes in levels of SP and LHRH. In the medial basal hypothalamic area and median eminence SP levels were found to be inversely related to the chronic T levels, whereas the LHRH levels were directly correlated. In the anterior hypothalamic and preoptic area, castration reduced levels of SP. Conversely, castration elevated levels of LHRH in this area. This inverse dynamic relationship between changing peptide levels was also observed in the rostral basal forebrain but not in the olfactory bulbs. In most of these forebrain regions, the dose-response curves for the experimental groups could not incorporate the peptide levels in the sham-operated control group. SP levels in the brain stem showed a monotonic inverse relationship to circulating T levels which did include the control group values.(ABSTRACT TRUNCATED AT 250 WORDS)

Annals of the New York Academy of SciencesVolume 519, Issue 1 p. 287-298 The Chemistry of Vomeronasally Detected Pheromones: Characterization of an Aphrodisiac Proteina ALAN G. SINGER, ALAN G. SINGER The Rockefeller University New York, New York 10021Search for more papers by this authorWILLIAM C. AGOSTA, WILLIAM C. AGOSTA The Rockefeller University New York, New York 10021Search for more papers by this authorANDREW N. CLANCY, ANDREW N. CLANCY Worcester Foundation for Experimental Biology Shrewsbury, Massachusetts 01545Search for more papers by this authorFOTEOS MACRIDES, FOTEOS MACRIDES Worcester Foundation for Experimental Biology Shrewsbury, Massachusetts 01545Search for more papers by this author ALAN G. SINGER, ALAN G. SINGER The Rockefeller University New York, New York 10021Search for more papers by this authorWILLIAM C. AGOSTA, WILLIAM C. AGOSTA The Rockefeller University New York, New York 10021Search for more papers by this authorANDREW N. CLANCY, ANDREW N. CLANCY Worcester Foundation for Experimental Biology Shrewsbury, Massachusetts 01545Search for more papers by this authorFOTEOS MACRIDES, FOTEOS MACRIDES Worcester Foundation for Experimental Biology Shrewsbury, Massachusetts 01545Search for more papers by this author First published: December 1987 https://doi.org/10.1111/j.1749-6632.1987.tb36304.xCitations: 29 a This work was supported in part by NIH Grants HD19764 (to A.G.S.) and NS12344 (to F.M.). AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume519, Issue1The Terminal Nerve (Nervus Terminalis): Structure, Function, and EvolutionDecember 1987Pages 287-298 RelatedInformation

The effects of olfactory bulbectomy on circulating gonadotropin, prolactin and testosterone levels and on the testicular and pituitary responses to shortening of day length were studied in Syrian hamsters. Adult animals maintained on a 14L:10D cycle were sham-operated or sustained bilateral radical olfactory bulbectomies by aspiration to remove the main and accessory olfactory bulbs and the adjacent regions of the anterior olfactory nucleus. They were then maintained either on the long photoperiod or housed on a 10L:14D cycle. Testicular length was measured at weekly intervals over a 5-mo period. Sham-operated controls exhibited the normal pattern of testicular regression and eventual recrudescence on the short photoperiod. Testicular regression was significantly reduced in bulbectomized animals. Many of these animals showed no regression; others exhibited a reduced degree and/or shortened duration of regression. Serum levels of follicle-stimulating hormone (FSH) were substantially elevated in bulbectomized males maintained in long days. Their serum levels of luteinizing hormone (LH), prolactin and testosterone remained within the range for shams on long photoperiod. In short days, the bulbectomized animals showed the normal, pronounced decline in circulating prolactin levels. Serum FSH and LH levels also showed substantial declines, but the FSH levels were not reduced below the range for controls in long days, and the decline in LH levels was not as great as that for controls in short days.(ABSTRACT TRUNCATED AT 250 WORDS)

Previous research has shown that a urinary pheromone of female mice acts via the vomeronasal organ of the accessory olfactory system to elicit rapid release of luteinizing hormone (LH) in conspecific males. Several experiments were conducted to examine the importance of sexual experience for gonadotropin responses in male mice to female urine, male urine, saline, or mixtures of these stimuli. Both sexually naive and sexually experienced male mice had significantly higher plasma LH levels after presentations of female urine than after presentations of male urine. However, sexual experience appeared to increase the reliability of the short-latency gonadotropin response to female urine relative to a sexually neutral component of urine such as sodium chloride, and male urine appeared to suppress spontaneous LH secretion episodes in both naive and sexually experienced males. Subsequent experiments with sexually experienced subjects demonstrated that male mouse urine is a powerful suppressant of LH release in other males. Specifically, female mouse urine mixed with male urine failed to elicit LH responses in male subjects, whereas female urine mixed with saline was highly effective. Urine obtained from castrated male donors was as potent as urine from intact males in suppressing the gonad otropin response to female urine. The suppressive activity in male mouse urine thus does not appear to be critically dependent on gonadal hormones. The existence of a potent stimulatory pheromone in female urine and a potent suppressive pheromone in male urine makes male mice an excellent model system for studying the neural regulation of LH secretion.

Hormonally regulated proteinaceous material secreted in hamster vaginal discharge is detected via the vomeronasal organ and elicits copulatory behavior in males. The major soluble protein in estrous vaginal discharge has been isolated, characterized by molecular weight and amino acid content, and shown to have substantial aphrodisiac activity. The aphrodisiac activity of the purified protein is abolished by heating or proteolysis, and the native protein retains the activity after procedures for removing possible ligands such as volatile odorants, steroids, and peptides. This evidence that the protein is a reproductive pheromone indicates that the mammalian vomeronasal organ can mediate sensory detection of behaviorally relevant macromolecules.

The organization of intrinsic axonal projections of principal neurons in the main olfactory bulb (MOB) was studied in hamsters by using wheat germ agglutinin-horseradish peroxidase (WGA-HRP) and fluorescent dyes. Punctate injections of either WGA-HRP or fast blue (FB) that are restricted to small sectors on one side of the MOB produce comparably restricted fields of retrograde labeling on the opposite side. Label is found predominantly in superficially situated (middle and external) tufted cells that lie near and at the border between the external plexiform and glomerular layers. Few of the deeper middle tufted, internal tufted, or mitral cells and no external tufted cells that lie in the superficial two-thirds of the glomerular layer are labeled in regions remote to the injection site. Anterograde transport of WGA-HRP from the injection site labels axons that travel dorsally and ventrally in restricted bands through the internal plexiform layer and then terminate within this layer in the punctate sector on the opposite side that contains retrogradely labeled neurons. Such reciprocal projections between opposing regions of the medial and lateral sides of the MOB are found at all rostrocaudal and dorsoventral levels. When punctate injections of FB into the MOB are paired with restricted injections of a second fluorescent tracer (nuclear yellow or diamidino yellow dihydrochloride) into the appropriate sector of pars externa (pE) of the anterior olfactory nucleus, the punctate region of remote retrogradely labeled principal neurons is embedded within a topographically restricted longitudinal wedge of retrogradely labeled mitral and tufted cells that project extrinsically to or through pE. However, extremely few of these neurons are double-retrogradely labeled. The results reveal the existence of an intrabulbar associational system in which principal neurons engage in point-to-point, reciprocal projections between opposing regions of the medial and lateral MOB. Moreover, the results indicate that this associational system largely arises from superficially situated tufted cells distinct from those that support bulbofugal projections into the topographically organized interbulbar commissural system via pE.

Journal Article Evidence for morphologically, neurochemically and functionally heterogeneous classes of mitral and tufted cells in the olfactory bulb Get access Foteos Macrides, Foteos Macrides Worcester Foundation for Experimental BiologyShrewsbury, MA 01545, USA Search for other works by this author on: Oxford Academic PubMed Google Scholar Thomas A. Schoenfeld, Thomas A. Schoenfeld Worcester Foundation for Experimental BiologyShrewsbury, MA 01545, USA Search for other works by this author on: Oxford Academic PubMed Google Scholar James E. Marchand, James E. Marchand Worcester Foundation for Experimental BiologyShrewsbury, MA 01545, USA Search for other works by this author on: Oxford Academic PubMed Google Scholar Andrew N. Clancy Andrew N. Clancy Worcester Foundation for Experimental BiologyShrewsbury, MA 01545, USA Search for other works by this author on: Oxford Academic PubMed Google Scholar Chemical Senses, Volume 10, Issue 2, 1985, Pages 175–202, https://doi.org/10.1093/chemse/10.2.175 Published: 01 April 1985