Early expression of odorant receptors distorts the olfactory circuitry.

The odor response properties of a mammalian olfactory sensory neuron (OSN) are determined by the tightly regulated expression of a single member of a very large family of odorant receptors (ORs). The OR also plays an important role in focusing the central projections of all OSNs expressing that particular receptor to a pair of stereotypic locations (glomeruli) in each olfactory bulb (OB), thus creating a spatial map of odor responses in the brain. Here we show that when initiated late in neural development, transgenic expression of one OR in almost all OSNs has little influence on the architecture of the OB in mice.

Prominent roles for odorant receptor coding sequences in allelic exclusion.

Mammalian odorant receptors (ORs) are crucial for establishing the functional organization of the olfactory system, but the mechanisms controlling their expression remain largely unexplained. Here, we utilized a transgenic approach to explore OR gene regulation. We determined that although olfactory sensory neurons (OSNs) are capable of supporting expression of multiple functional ORs, several levels of control ensure that each neuron normally expresses only a single odorant receptor.

Activity-dependent plasticity in the olfactory intrabulbar map.

In mammals, each olfactory bulb contains two mirror-symmetric glomerular maps. Isofunctional glomeruli within each bulb are specifically linked through a set of reciprocal intrabulbar projections (IBPs) to form an intrabulbar map. We injected neural tracers into the glomerular layer on one side of the bulb and examined the resulting projection on the opposite side.

Effects of sleep disruption on rat dentate granule cell LTP in vivo.

Sleep frequently fragmented or disrupted for prolonged periods can result in mood changes and impaired mental ability and performance. Sleep deprivation is defined as depriving a person or organism of sleep for various periods of fixed durations. Sleep disruption (SD) occurs when a person is awakened at any time when they would normally be sleeping; sometimes on a schedule but usually unexpectedly.