Major depression and Alzheimer׳s disease (AD) are often observed in the elderly. The identification of specific markers for these diseases could improve their screening. The aim of this study was to investigate long-term odor recognition memory in depressed and AD patients, with a view to identifying olfactory markers of these diseases. We included 20 patients with unipolar major depressive epi...

The ad hoc genetic correlation between ethanol sensitivity and learning mechanisms in Drosophila could overemphasize a common process supporting both behaviors. To challenge directly the hypothesis that these mechanisms are singular, we examined the learning phenotypes of 10 new strains. Five of these have increased ethanol sensitivity, and the other 5 do not. We tested place and olfactory memo...

Few attempts have been made to develop an olfactory test that captures episodic retention of olfactory information. Assessment of episodic odor memory is of particular interest in aging and in the cognitively impaired as both episodic memory deficits and olfactory loss have been targeted as reliable hallmarks of cognitive decline and impending dementia. Here, 96 healthy participants (18-92 year...

Individual Camponotus fellah ants perceive and learn odours in a Y-maze in which one odour is paired with sugar (CS+) while a different odour (CS-) is paired with quinine (differential conditioning). We studied olfactory retention in C. fellah to determine whether olfactory learning leads to long-term memory retrievable 24 h and 72 h after training. One and 3 days after training, ants exhibited...

Extensive molecular, genetic, and anatomical analyses have suggested that olfactory memory is stored in the mushroom body (MB), a higher-order olfactory center in the insect brain. The MB comprises three subtypes of neurons with axons that extend into different lobes. A recent functional imaging study has revealed a long-term memory trace manifested as an increase in the Ca(2+) activity in an a...

Impaired olfaction is an early pre-motor symptom of Parkinson's disease. The neuropathology underlying olfactory dysfunction in Parkinson's disease is unknown, however α-synuclein accumulation/aggregation and altered neurogenesis might play a role. We characterized olfactory deficits in a transgenic mouse model of Parkinson's disease expressing human wild-type α-synuclein under the control of t...

UNLABELLED Numerous clinical reports underscore the frequency of olfactory impairments in patients suffering from major depressive disorders (MDDs), yet the underlying physiopathological mechanisms remain poorly understood. We hypothesized that one key link between olfactory deficits and MDD lies in hypercortisolemia, a cardinal symptom of MDD. Corticosterone (CORT) is known to negatively corre...

Processing of olfactory information in the antennal lobes of insects and olfactory bulbs of vertebrates is modulated by centrifugal inputs that represent reinforcing events. Octopamine release by one such pathway in the honeybee antennal lobe modulates olfactory processing in relation to nectar (sucrose) reinforcement. To test more specifically what role octopamine plays in the antennal lobe, w...

Increased AMPA signaling is proposed to mediate long-term memory. Rat neonates acquire odor preferences in a single olfactory bulb if one nostril is occluded at training. Memory testing here confirmed that only trained bulbs support increased odor preference at 24 h. Olfactory nerve field potentials were tested at 24 h in slices from trained and untrained bulbs. A larger AMPA component and a sm...