Olfactory lobe

In vertebrates the neurons for olfaction are located in the nose mucosa and consist of short neurons with a peripheral ending endowed with odorant receptors for a large number of molecules in the environment. Each receptor neuron only contains one odorant receptor and is connected directly with the olfactory lobe of the brain. The vertebrate olfactory system must cope with a staggering developmental problem how to connect millions of olfactory neurons expressing different odorant receptors to appropriate targets in the brain. 

In many deep-sea fish, the olfactory capsule and olfactory lobes are much larger in males than in females. The olfactory lobe of the brain may even change in size in the same individual ripe males of Gonostoma hathyphilus (Gonostomati-dae) have extremely large olfactory lobes. With sex reversal, their olfactory lobes regress (Badcock, 1986). 

Exposing young male prairie deer mice, Peromyscus maniculatus, to soiled bedding from adult male conspecifics retards the growth of their testes and seminal vesicles. Male, but not female, urine applied to the nose has the same effect. Removal of the olfactory lobes at the age of 3 weeks blocks this effect (Lawton, 1979). The reproductive development of male California voles, M. californicus, is suppressed hy chemical cues from the mother (Rissman etah, 1984). 

Carnosine is also associated with nervous tissues, including the brain, where it is concentrated especially in the olfactory lobe (Bonfanti et al., 1999 de Marchis et al., 2000). However, human cerebral spinal fluid contains homocamosine but no carnosine (Huang et al., 2005). 

Carnosine is an avid chelator of metal ions (Baran, 2000). Complexes with calcium, copper, and zinc ions have been described (Trombley et ah, 2000). It is possible, therefore, that carnosine could exert some sort of control of calcium metabolism in muscle tissue (heart or skeletal). It is also likely that the dipeptide controls the availability of zinc ions in neuronal tissue, especially the olfactory lobe where both carnosine and zinc are enriched (Bakardjiev, 1997 Bonfanti et ah, 1999 Sassoe-Pognetto et ah, 1993). Zinc-camosine complexes, called polaprezinc, are also effective in the repair of ulcers and other lesions in the alimentary tract (Matsukura and Tanaka, 2000). 

N-a cetyl-cam os i ne or the decarboxylated form carcinine. In fact N-acetyl-camosine has been proposed as a prodrug to treat cataracts in the eye lens, as the acetyl group is readily removed intracellularly (Barbizhayev et ah, 2004) (see section on cataracts for more details). An alternative way to evade serum camosinase activity would be to introduce carnosine via nasal administration (Hipkiss, 2005). This route may be particularly appropriate for raising carnosine levels in the brain as the olfactory lobe is normally enriched in the dipeptide. 

Examine the head, upper and lower jaws and lips, snout, naris, diagrams and relevant descriptions correspond. Nasolabial sul-cus/cleft, nasal cavity and septum, oral cavity, palate, palatine ridges, incisors, cranium, pinna, eyelid, eye/lens, retina, cornea, vitreous and aqueous chambers, nasopharynx, olfactory lobe, cerebral hemispheres, lateral ventricles, cranial nerves, third ventricle, pituitary, pineal gland, thalamus, perimeningeal space, and internal ear. 

After inhalation exposure of mice to [ 4C]-/)ora-xylene, methylhippurate accumulated in nasal mucosa and the olfactory bulb, possibly due to axonal flow-mediated transport of the methylhippurate from the mucosa, where it is formed, to the olfactory lobe of the brain (Ghantous et al., 1990). Inhalation exposure of rats to /weto-xylene with or without ethyl acetate showed that ethyl acetate caused a decrease in the blood concentration of zweto-xylene (Freundt et al., 1989). 

Dual wavelength measurement with the BHRP was straightforward, because it does not have filters. The skulls of the mice and rats were exposed and small holes were drilled at the frontal cortex and olfactory lobes in order to insert the BHRP. Since the probe has a high spatial resolution and was kept in contact with the tissue surface during the experiment, the spectral changes at exactly the same point on the brain could be compared. 

VIP is a neurotransmitter in the cerebral cortex, the hypothalamus, amygdala, hippocampus, corpus striatum, and the vagal nuclei of the medulla oblongata (131,132). VIP receptors are widely distributed in cerebral cortex, amygdaloid nuclei, hippocampus, olfactory lobes, thalamus, and the suprachias-matic nucleus, and are present in lower concentrations in the hippocampus, brainstem, spinal cord, and dorsal root ganglia. VIP is also involved in the release of other hormones such as CRH, PRL, oxytocin, and vasopressin. 

Limbic system detect a gene mutation. The method uses the coupling of two adjacent synthetic oligonucleotides aligned on the template of the target deoxyribonucleic acid (DNA). Area of the brain associated with small, involuntary functions, emotions and behaviour. Comprises the hypothalamus, parahippocampus, olfactory lobe, dentate gyrus, amygdala, anterior thalamus, fornix and stria terminalis. 

Jhaveri D., Sen A. and Rodrigues V. (2000b) Mechanisms underlying olfactory neuronal connectivity in Drosophila - the atonal lineage organizes the periphery while sensory neurons and glia pattern the olfactory lobe. Dev. Biol. 226, 73-87. 

From the receptor cells nerves pass through the olfactory lobes at the front end of the brain direct to the central basal region, the part known as the "limbic system." This forms part of our deep-seated unconscious mind, being associated with the control of emotion and sexual activity, as well as with feelings of pleasure. In evolutionary terms it is also the oldest part of the brain, providing evidence of the early and continuing importance of the sense of smell in animal behavior. 

The sense of smell depends initially upon the interaction between the stimulus and the olfactory epithelium. It is believed that the molecule must be bound by a receptor on the cilia. The binding process causes olfactory nerve impulses to travel from the sensory cell to the olfactory lobe of the brain. The brain interprets the incoming signals by associating them with a previous olfactory experience. This is how the nose distinguishes between perceived air qualities [5]. 

Strausfeld N, Reisenman CE (2009) Dimorphic olfactory lobes in the Arthropoda. Ann N Y Acad Sci 1170 487-496... 

Fig. 7.2 Schematic representations of chemosensory pathways in the brain, (a) Lateral antennular neuropil (LAN) pathway. dCRNs and MRNs from sensilla on the lateral (LF) and medial (MF) antennular flagellum project somatotopically into both lobes of the LAN and couple directly to antennular motoneurons (MN), (b) Olfactory pathway. ORNs project nontopographically into the olfactory lobe (OL) which is organized into glomeruli. Information is processed by various types of multiglomerular local intemeurons (LN) and output is provided by multiglomerular projections neurons (PN) ascending to the lateral protocerebrum in the eyestalk ganglia...

Axons from chemo- and mechanosensory sensilla on the antennular flagella course within branches of the antennular nerve to three major target areas in the deutocer-ebrum The olfactory lobes (OL), the lateral antennular neuropil (LAN), and the median antennular neuropil (MAN). Backfilling techniques in spiny lobsters have established that ORNs connect with synaptic targets exclusively within the OL, while dCRN and MRN axons target the LAN and MAN (Schmidt et al. 1992 ... 

Schmidt M, Ache BW (1992) Antennular projections to the midbrain of the spiny lobster. II. Sensory innervation of the olfactory lobe. J Comp Neurol 318 291-303... 

Fig. 8.6 Immunohistochemical localization of the neuropeptide SIFamide in the brain of the giant robber crab Birgus latro (Harzsch and Hansson, unpublished data black-white inverted fluorescent images), (a) Horizontal vibratome section of the median brain. The olfactory lobes (OLs) and the hemiellipsoid bodies (HE) dominate the brain, (b) Detail of the hemiellipsoid body showing its layered structure, (c) The OL seems to be composed of three units...

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