Olfactory deficits

Corcoran C, Whitaker A, Coleman E, Fried J, Feldman J, et al. 2005. Olfactory deficits, cognition and negative symptoms in early onset psychosis. Schizophr Res 80 283-293. 

Until recently, olfaction has received limited attention in pathological conditions in man. Recent interest in the human olfactory system has been brought about, in part, by neuropathological investigations that described the presence of histological lesions in olfactory-related structures in Alzheimer s disease (Reyes et al. 1987 Pearson et al. 1985 Esiri and Wilcock, 1984), a condition clinically characterized by progressive intellectual decline and behavioral abnormalities. Other clinical studies have shown that olfactory deficits occur in patients with Alzheimer s disease (Doty and Reyes, 1987 Doty et al. 1988), Parkinson s disease (Doty et al. 1988) and schizophrenia. 

Prudhomme JC, Shusterman DJ, Blanc PD. 1998. Acute-onset persisten olfactory deficit resulting from multiple overexposures to ammonia vapor at work. J Am Board Fam Pract 1 l(l) 66-69. 

A behavioral test of a peripherally-induced olfactory deficit. Physiol. Behav., 6 619-621. 

Male mice learn about female cues. In the presence of females, a male emits ultrasonic vocalizations. These vocalizations become less frequent after extirpation of the VNO. The more experience a male has had with females, the smaller the deficit he suffers. The learning is mediated by interaction between the main olfactory system and the accessory olfactory system after vomeronasal deprivation, olfactory cues maintain the behavior (Wysocki etal., 1986). 

Oxytocin typically has a facilitative effect on affiliative behaviors (Witt et ah, 1992), including parental and reproductive behaviors and infant-mother attachment. Oxytocin facilitates social memory, with knockout mice displaying social memory deficits it facilitates conditioning to maternal-related olfactory cues (Nelson and Panksepp, 1996). 

Thus, a GSH deficit has consequences consistent with the concept of functional disconnectivity, as hypofunction of NMDA-R and alteration of dopamine signaling have been observed. When imposed on animals during development, a GSH deficit induces also a structural disconnectivity, as revealed by the decrease in dendritic spines and parvalbumin-immunoreactivity of inhibitory intemeurons in the prefrontal cortex Finally, a transient GSH deficit during brain development causes deficits in visual recognition and olfactory integration. 

The clue to this transition seems to be found in the sense of olfaction. Early in the course of AD, degeneration occurs in the entorhinal cortex-hippocampal-subicular complex (Price and Morris, 1999). The olfactory bulb, particularly the anterior olfactory nucleus, shows numerous neurofibrillary tangles (NFTs). Odor identification deficits during life may be associated with NFTs in the hippocampus (Wilson et al., 2007). 

Additionally, cacosmia, a subjective sense of altered olfactory function and feeling ill on exposure to chemical odors, which is experienced by many MCS patients, might be associated with neurocognitive dysfunction. However, MCS patients do not demonstrate a consistent or specific pattern of neurocognitive deficits and disturbances of memory and attention, which may be a result of depression and anxiety. Some have suggested that cascosmia as... 

Luo AH, Cannon EH, Wekesa KS, Lyman RF, Vandenbergh JG, Anholt RR (2002) Impaired olfactory behavior in mice deficient in the alpha subunit of Go. Brain Res 941 62-71 Mandiyan VS, Coats JK, Shah NM (2005) Deficits in sexual and aggressive behaviors in Cnga2 mutant mice. Nat Neurosci 8 1660-1662... 

Moriguchi S, Tanaka T, Tagashira H, Narrais T, Fukunaga K (2013) Novel nootropic drug sunifiram improves cognitive deficits via CaM kinase II and protein kinase C activation in olfactory bulbectomized mice. Behav Brain Res 242 150-157... 

Mason, J. R., Clark, L., Morton. T. H. 1984. "Selective Deficits in the Sense of Smell Caused by Chemical Modification of the Olfactory Epithelium." Science, 226 1092—1094. 

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