Odour memory

The nose and its associated structures responsible for our sense of smell linking our nervous and endocrine (hormonal) systems serves to make our perception and reactions to an odour a unique experience. This reinforces its significance in the psychosomatic (mind-body) interchange. Scent can affect mood and emotion at a deep level. People often find that scents are powerfully effective in provoking long-forgotten memories. 

Connolly et al. (1996) transgenically expressed a mutant Gas protein (CG 2835, using the G mutant) in the mushroom bodies which constitutively activates the cyclase, hence presumably rendering any modulation of cyclase activity impaired. This leads to an abolishment of memory scores after odour-shock learning. Whether a knockdown of the rut-cyclase by means of RNA interference would lead to a similar abolishment of short-term odour-shock memory is unknown. 

Thus, synaptic plasticity in the mushroom bodies is sufficient (rat-rescue) and necessary (Ga ) to establish a short-term memory trace during odour-shock training. 

Memory scores for odour-shock learning decay characteristically faster than for odour-sugar learning (Tempel et al. 1983) and... 

It seems that chemosensation and chemosensory learning in Drosophila are beginning to be understood fairly well, in particular in the genuinely sensory aspects, and in terms of odour-taste memory trace formation. The remaining terra... 

Chu, S., Downes, J. J. 2000. "Odour-Evoked Autobiographical Memories Psychological Investigations of Proustian Phenomena." Chemical Senses, 25 111—116. 

Olfaction is a powerfully emotive sense. An odour has the ability to remind us of the past for instance, to bring back memories of situations from our youth, or to remind us of friends or family. It also has the ability to promote feelings of relaxation or comfort, a property which is made much of by aromatherapists, who also use it to aid the therapeutic properties of massage. 

Smell is the sense most closely linked to the emotional centres of our brain. Although more of our brain is dedicated to vision than to any of the other senses, more of our genes are devoted to the sense of smell (1%) than to the detection of all the other kinds of sensory information. We possess an excellent ability to detect and discriminate odours but we have great difficulty in describing them verbally. Despite this fact, odours have an extraordinary ability to remind us of events and memories of our past, sometimes from many years ago. 

F. R. Schab and R. Crowder, Memory for Odours, Erlbaum Publishers, 2000. 

Todrank, J., Heth, G., and Johnston, R. E., 1999b, Social inleiaclion is necessary for discrimination between and memory for odours of close relatives in golden hamsters. Ethology 105 771-782. 

Myers, C. S., 1903, Smell. I. Olfactory acuity and discrimination of odour strengths, II. Memory and discrimination of odours. Rep. Cambridge Anthrop., Expedition to Torres Straits, 2, pt. 2, Univ. Press, Cambridge. 

Larsson, M. and Backman, L. (1997). Age-related differences in episodic odour recognition the role of access to specific odour names. Memory, 5, 361-78. 

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